EV Ute Conversion - NZ

EV-Ute on a diet

2010-04-22T22:48:00.000-07:00

Well the red ute has been rolling around my home town, Dunedin, for well over a year and a half by now. It has received four Warrants of Fitness (required every six months).
The last WOF was the first one that was more than routine. The ute was rejected on rear brakes and RUST! The word sent a cold shiver through me when I was given the news. Rust was what killed Gavin Shoebridge's EV Mitzi. Suddenly the wisdom of investing so much money in the conversion of a 20 year old ute seemed to be mis-founded ...
Once I calmed down I set about locating the appropriate professionals to make everything OK again. Inside a two days the brakes were completely overhauled and a section of the cab ground away to allow new sheet steel to be welded in place. A quick trip to the testing station and I was street legal again.
Speaking of bureaucracy, the central government removed the need to pay Road User Charges for electric vehicles. So, I no longer need to buy RUCs. Seems like a cheap political promise to please the sustainability lobby, since there are still so few electric vehicles in New Zealand.
Anyway, to the point of the post. The ute needs to go on a diet. It is abundantly clear that the light any EV is the better it is for almost everything. They go fast sooner. They have more range and they stop quicker under emergency braking. My ute was, regretfully, showing signs of mid-age spread. I simply need to trim away the kilos in order to enjoy a nippier, longer range EV. The butchers bill for slicing away weight looks like this:

Taking off the tow bar / trailer coupling
Leaving the spare tyre at home
Cutting away most of the flat deck steel except around the battery box
Removing the automotive 12V battery and replacing it with a small storage battery

It's a work in progress, but I'll let you know how I get on.

Taking a rest and just driving it

2008-12-06T22:39:00.000-08:00

I haven't blogged on the subject of the EV ute for quite a long time. I'm reminded of the title of a post that Jerry Halstead had on his website (http://www.evconvert.com/), along the lines of "Still crazy after all this time". He was reflecting that even though his entire home and life had been turned upside down by the arrival of his first-born last year, and that his previous energy put into the Probe conversion or website maintenance had fallen flat, that he was still hooked by the thought of getting back onto it.
I've been taking a rest from obsessive EV conversion activity since completing the Courier and the seminars that we ran on EV conversion in Dunedin, Invercargill and Christchurch. But, I have been fortunate that the EV ute has been performing flawlessly for almost a thousand kilometres. It takes time to run up a 1000 km on around-town trips, but it does eventually happen. On the technical side, I made a minute adjustment to the control circuit that solved the tendancy for the two breakdowns of the EV. In June and August the EV ute rolled to an unplanned halt due to the main contactor sticking open. I had set up the PB6 potentiometer ('pot-box') as recommended with the micro-switch switching the control circuit. This meant that whenever the foot was raised off the accelerator that the micro-switch would open and the main contactor would open. You could hear it going 'thunk, thunk' as you eased off the accelerator and applied it again. The breakdowns occurred when the second 'thunk' didn't happen and the contactor stuck open. I thought about and asked other EV drivers with the Curtis configuration. Eventually, I cut the micro-switch out of the control circuit. Now there is a single 'thunk' of the main contactor closing when I turn the key switch on and it stays closed until the end of the journey. The breakdown has never repeated itself.
I have also learned to use the gearbox of the ute more effectively over the last few months. I routinely pull away in second gear rather than third. I am also changing up into fourth gear as soon as I reach 50 km/h, instead of whining away in third. It's making for a more positive and quieter drive. I also suspect that the the gear shifting is saving the range through fewer amps drawn during a typical acceleration / deceleration cycle. We have also been getting more adventurous in hill-climbing some of the steeper Dunedin hills, going routinely up to Pinehill using the state highway.
What's been happening in the New Zealand EV scene. Quite a lot, and not as much as I thought might be the case. Gavin Shoebridge (a.k.a. KiwiEV) has continued adding to his website and throwing the net further. I thoroughly recommend his site for the information, dry wit and broadcaster standard presentation (on a beer budget). The Christchurch EV scene has livened up considerably as emphasized by the success of the EV Open Garage events. David Newton is a key person up there. Check out his www.greenev.co.nz website, complete with links to YouTube step-by-step descriptions of his Alto conversion. The NZEVA section of DIYElectricCar gives us a bit of a window on the Christchurch happenings, plus the news from Auckland, Nelson and a number of centres (http://www.diyelectriccar.com/ if you haven't been there already).
For the first time there is a commercial angle to EV conversion in New Zealand. Hyundai announced earlier in the year that they were introducing the commercial conversion of their Hyundai Getz. The conversions are being done on petrol Getz' using the approach of Ross Blade (BladeRunner) of Melbourne, Australia. But the conversion are being done in New Zealand. The production target for 2009 is 200 conversions. Also arriving on New Zealand shores next year is the Mitsubishi MiEV factory production EV based on the 600cc Colt.
I got the impression in the winter that things were really building up. EV converters were becoming minor celebrites, Gavin starred on TV news and then a TV ad! I was invited to deliver a Tech course on EV conversion and asked to endorse a proposal for a commercial conversion service (I was interested in the first and not in the second). But, there was a real bubble and bounce to the EV conversion movement.
What happened? I suspect that Business As Usual changed in a few important ways. Firstly, the ever-increasing oil price, peaking at $147 a barrel, scared a lot of oil-importing countries silly. So, a lot of direct country-to-country deals and oil sales agreements were concluded between net importers of oil and oil-exporting countries that bypassed the international oil auctions. Secondly, the credit crunch bit sharply in September 2008. Capital fled the commodity markets to shore up liquidity and a massive amount of debt was called without being rolled over as the markets / institutions reacted in fear and self-preservation. The oil futures market lost volume of trades and therefore ceased to influence the day price as much. The almost immediate demand destruction for fuel hit at just the point that the increased production from the OPEC countries arrived in the importing countries. The result is an oil price that has fallen over US$100 in a few short months. The gathering recessionary pressures cutting spending on commodities are keeping the oil price low. The price at the pump has fallen to levels last seen several years ago and this gives the appearance that the relentless climb of the oil price was just a bad dream.
A lot of interest in EV conversion centred on the relative price of the "fuels". At the top of the oil price spike this year, the average fuel cost was about 12 cents a kilometre. The average recharging cost for an EV (on electricity tariff only) was (and still is) 4.5 cents a kilometre. Of course, the conversion cost and the need to continually save up for new batteries jumps the EV running cost up substantially, depending on how you calculate the per km cost. But, the perception was out there amongst people that converting to EV was a way of insulating themselves from the rising fuel price. With the perception that fuel prices are back to Business As Usual, the urgency around EV conversions is dissapating. This is a taking a lot of the wind out of the sails of a viable EV conversion movement. The other effect of the credit / share market / economic crisis is the cost of securing EV conversion parts has risen. ZEVA announced in September that the crisis was forcing a revision of pricing and it can't be easy for on-sellers like Ian Hooper at ZEVA. The New Zealand dollar dropped from almost 80 cents against the US dollar in August to about 50 cents currently. That is a lot of purchasing power lost to the New Zealand converter for buying equipment and specialised batteries like LiFePO4.
Maybe the response is to look at home-grown approaches to EV conversion? I am really interested in the application of used AC induction motors and used Variable Frequency Drives (VFD) from industrial cast-offs to be used in EV conversions. Graeme Church of Ashburton is doing a Ford Courier conversion using just this gear. He was inspired by Tuarn Brown of Perth who had successfully done a Suzuki jeep and is currently converting a flat deck ute. Within innovation such as theirs lies hope.

Spreading the Word

2008-09-06T01:59:00.000-07:00

Now don't think I am going to go all preachy with a title like "Spreading the Word", but I have been out singing the praises of converting to battery electric in the last few months.

It all started with a suggestion for Adrianne. "Shouldn't you being giving a talk on EV conversion now that you're almost finished", she asked one day in April 2008. I muttered something about that being a good idea and promptly forgot about it, mainly because I was bogged down in the minutae of actually finishing the conversion. But Adrianne didn't forget. She got onto the details of finding a venue and setting up publicity. While I was pre-occupied with spending every waking hour doing the conversion or thinking about, she set the date for presentation and made all of the necessary arrangements. While I was immensely grateful, I started to freak out a little bit as the date approached and I hadn't prepared my talk, finished the conversion or got it road legal!

On 8 June 2008 we opened the doors on a lecture hall provided by Otago Polytechnic and it almost immediately filled up to its 100 person capacity! At 10 minutes before the presentation was due to start we had to close the doors and Adrianne had the awful job of turning over a hundred people away. Luckily, she had the forethought to collect 76 names and details of folks who were still keen on coming to a second presentation. Those excluded from the main act behind closed doors had to console themselves with looking over Mike Laba's EV Mini. In the days leading up to the presentation date, the price of oil had leapt US$14 and the price of fuel was climbing to pay for it. The was a real sense of concern as to where the rise was going to stop and the idea of electric car conversion was just starting to permeate around. So, Adrianne had done too good a job of publicising the presentation to a newly receptive public.

The presentation went well. My throat was turning into dry parchment by the time the question and answer session was starting to warm up. Luckily, Mark Jackson jumped in and wound up the whole exercise in a good fashion. People were fascinated with the idea and awestruck when Mike Laba said his Mini took 80 cents of power to charge. However, we did not sugar-coat the conversion costs and made sure folks knew the realities of range and battery limitations. Below is a shot of me giving the presentation.

We then had the problem of meeting our commitment for the second presentation. Adrianne had a difficult job in securing a venue that would take more people. We eventually got the Logan Park High School auditorium with a capacity of 250 persons. The date was set for 29 June and I had time to get my electric ute on the road. So, this time we had Mike's Mini and my ute to show off. It was a good counterpoint between the two. My EV ute with old and heavy technology alongside Mike's lithium powered light-weight conversion. Mine weighs 2,000 kg, while Mike's comes in at 630 kg. What a contrast! Anyway, we had a break between presentations where we displayed the conversions to the audience. I got to drive around the car-park to prove that they do indeed make very little sound. About 230 people turned up and donated a dollar or two to the cost of the venue. The questions were more advanced and I got the idea that some serious thought had gone into the conversion proposition. With a few of the questions I had a fairly good idea which websites had prompted them, so that proved that folks had been surfing and googling about EVs. The shot below is an unflattering photo of me squatting on the deck of my ute to show folks the rear battery pack.

http://www.odt.co.nz/your-town/dunedin/11523/electric-cars-again-power-big-crowd

The presentations were good idea and got the ball rolling on a few things. There was some serious talk about doing conversion around Dunedin, and further afield. One other upshot was a set of invitations to give a presentation in Invercargill and Christchurch from individuals that had travelled to be at the Dunedin presentations. I'll talk about these trips in the next post.

Finally Street Legal

2008-08-06T02:19:00.000-07:00

Trip Meter 160 km

The ute went for its final certification inspection. Passed, and the certification plates were riveted into the engine bay. With the certification process completed I could escalate the electric ute to a whole new level of bureaucratic process!

Next step down to the vehicle testing station. With the modifications to the ute certified the vehicle inspection could be done. The inspection is solely around the routine safety condition of the ute; brakes, steering, suspension, lights, seatbelts, exhaust system, fuel lines ... hang on a minute? Where are the exhaust and fuel line?? Fume and noise check!!

The electric ute was a real novelty for the inspectors. I warned them while waiting that I might need to explain how to drive it. So that was the first clue they had. Before long the electric ute had every single vehicle inspector looking it over and the rest of the cars being inspected were abandoned. I was summoned over to explain how the system worked, but they did a good job of working it out themselves. They where truly impressed with the small electric motor - "it's only the size of the gearbox!". I could see that they didn't quite believe that the ute could travel at least 100km/h with a motor that small. The ute passed everything, but I had to prove that the speedo worked. I suspected that was an ill-disguised ruse to get to ride around the block in it. They were like kids in a sand-pit!

Having passed the Warrant of Fitness, the next hurdle was registration. Is the ute petrol or diesel power? No? Oh well, there seems to be a space for electric here on the form... Then I needed to pay Road User Charges. What do you mean the mileage is at 169,960 km already, we have no record of you paying RUC before this? With all of that sorted out, I walked out to my ute with $547 less cash in my account and a much happier man.

Driving the ute home from work yesterday I was strangely elated. Strangely, because I was just like any other commuter on the streets that day, but I knew that something that they didn't. I was driving carbon-free and without the aid of hydrocarbon fuels. Somewhere, I imagined there was a windfarm, geothermal plant or hydro station turning the wheels of the ute. Elated, because even though it had only taken a year from decision to completion it had been a huge journey for Adrianne and I. It took over our life to some extent. It was not the 'smartest' thing for a couple in our position to do. But, in the end ideals had triumphed over expediency.

Next thing is to get Adrianne driving the ute. It is as much her ute as mine, and she has helped in any and every way she could during the conversion. Fortunately, this time I managed to avoid breaking her hand under an anvil as happened last time I had a DIY obsession!

Anyway, street legality is a real watershed. I feel like the electric ute is finally finished. In the interim of June and July while awaiting certification, I have been promoting electric car conversion around the South Island. Hopefully, in my next posts I'll explain how that happened.

Trip Meter @ 91 km

2008-06-22T01:59:00.000-07:00

Yesterday I drove the electric ute from the family workshop in Macandrew Bay to our house in North East Valley. The ute is still not quite legal for the road, so I am only doing 'low profile' driving. This was the first time driving through the city. Annoyingly, our certifier still has to do the final inspection before we take posession of the certification plates. We were not pleased to hear that he was on holiday in Europe and not due back til mid-July. But that's life. The upshot is that we can't register the ute without certification plates, and the registration expired on 28 May.

I should have also explained that our house is at the top of "almost the steepest street in the World". The next block over is Baldwin Street, which really is the steepest street in the world. In daylight and fine weather you can barely drive on Baldwin Street because the hordes of tourists who struggle up and down the steep grade. Our street is not quite as steep, but pretty damn close. So, whether the electric ute would be able to climb our steep to the top was a pretty significant question. If it could make it up under its own power, then we couldn't charge it and it really wouldn't be much use to us in the long-term. The question "will the ute be able to handle the hill" was one of these elephants in the corner type things that we tried not to talk about while it was still in doubt. So, when I turned off the main road of North East Valley I decided to pull over and check every thing. The controller was barely warm, which is fantastic. The cooling fans must be doing their job. I checked the gauges - 3/4 State of Charge and 150V resting voltage - perfect!. It just remained to tackle the hill.

With all systems GO and the hill in my sights I put the ute and second and accelerated moderately up the steepening grade. Everything went fine. As the grade reached its crux the current was spiking towards 300A I changed down to first. The XP-1263 motor pulled magnificantly and in a few moments we had crested and pulled into our garage. What a relief. Before that, I had experienced nightmares of the circuit breaker or one of the fuses blowing at the steepest point and having to guide the ute backwards down the hill with zero maneouvering power. Not only did it make it, but the hill did not seem to cause the merest twitch to the State of Charge, which put paid to the other nightmare (along the lines of the climb up the hill to our house taking a quarter of the battery charge).

The ute was finally home, and I put it on the charger. Another threshold has been successfully crossed and we are closer to an all electric future in our household. The batteries performed well and are steadily breaking in.

Today, we had people from Sustainable Dunedin (North Dunedin group) around to look at the electric ute in action. I think a few of them were a bit stunned by the battery electric idea at first. What is becoming normal to us is definitely new territory to the rest of the population. But awareness begins in small steps. One of the small steps, that we still owe the folks of Dunedin, is the follow-up public presentation to follow the sell-out talk from 8 June. As you will remember, we could not get everyone in, and had to turn lots away. This time we have secured a bigger venue at the Logan Park Highschool auditorium and set the talk date for 1pm, Sunday 29 June 2008 (a week away). We are having to request a gold coin collection for the venue hire this time, unfortunately (bigger venue, unavoidable hire charge). I'm looking forward to it. See you there.

First Dunedin Electric Conversion Talk

2008-06-08T13:06:00.000-07:00

Yesterday I gave the first public talk on the experience of doing an electric car conversion. Adrianne did a fantastic job of publicising it, including community newspapers and email lists. It was perhaps a bit too successful, since we could have filled the 100 seat venue at Otago Polytechnic twice over. We turned at least 76 people away at the door because we couldn't fit them in.

The talk was entitled "So you want to make an Electric Car" and continued on in that vein for about two hours. I covered basic EV technology, safety, conversion options, examples of good conversions and conversion costs. It seemed like a good model for introducing people to the concept and stepping stones to their own conversion. Mike Laba filmed the presentation and he plans to put together a DVD with the filming, the presentation files, some video he has produced of his electric Mini and other tit-bits. He is distributing the DVD once he has editted it for $18 a copy. Folks can order a copy from DunedinEV@gmail.com . Mike was also showing off his electric Mini during the break. My ute wasn't their because of delays in getting it legal for the road (more on that later).

I don't think this talk was the last. We might need to find a larger venue next time. We have also been invited down to Southland to give a similar presentation. It was an excellent opportunity to meet and talk with a lot of interesting folks. But it was also a chance to pass on some of the knowledge that I have gained from others over the past year.

Almost Legal

2008-05-28T23:53:00.000-07:00

Today I submitted the ute for its certification inspection of vehicle modifications.

Under the Transport Act and regulations, any vehicle which has received modifications must be inspected for certification before it is issued with a certification certificate and permitted to undergo the normal Warrant of Fitness inspection for road worthiness. That's as short and legally accurate description as I can come up with.

Certification of vehicle modifications has become out-sourced to the Hot Rod Association within a subsidiary called Certification New Zealand Ltd. Up and down the country there are accredited certifiers, usually car enthusiasts, who are endorsed to carry out inspections on behalf of Certification New Zealand. Unfortunately, a much smaller number of certifiers are rated to perform certification of electric vehicles. Luckily, one of the certifiers in Dunedin is a registered electrician, which allows him to get the electric certification endorsement. Gavin Shoebridge had to truck his car from New Plymouth to Auckland for the Tredia to be inspected by the closest certifier with the electrical endorsement. Gavin describes this and the process really well, and if you are interested in certification, you should definitely visit his website and look at "The Inspection" http://www.kiwiev.com/Step%20Eighteen%20-%20The%20Inspection.htm
Just like Gavin, I was really nervous about certification. The morning's inspection didn't go any easier because -

The morning was really cold, around -1oC, and those sort of temperatures reduce the performance and range of the battery pack, and
I had to drive the ute to the certifier's place about 12 km on frosty roads
I was almost there and the main contactor decided to stick open, leaving me without power and stranded without a multi-meter to track down the problem. Thankfully, a healthy thump on the contactor coil solved the stickiness. But I arrived late, and then
The certifier told me this was only his second electric vehicle inspection, and besides the last guy had gone away with a list of things to fix, and had never returned!

None of the above boosted my confidence. As we went through the regulation guidelines written for electric motor conversions, there were all of these things that I hadn't thought of in quite the way that the certifier considered they should be interpreted. We had a fair bit of discussion and we started looking over the conversion once we put the paperwork aside. Then I began to have a sense that the inspection wasn't going too badly. We went for a test drive and the ute pulled nicely up the steepest road in Andersons Bay, Cemetry Hill. After we got back, the certifier put together the 6 point list of things that I still had to complete, mostly around warning signs and finishing of the battery boxes. I was disappointed that the ute still needed to be re-inspected. But, at the same time, I was relieved that the list wasn't long or difficult.

Once I pass the re-inspection, and you can bet that I will keep bring the ute back until it is 100% passed, I can go for the Warrant of Fitness. The inspectors for the WOF will only inspect the normal safety issues; tyre, brakes, lights and seat belts. They might have trouble finding any exhaust system, or fuel lines to check off their list! With that out of the way, all I need to do to be fully legal is re-register the ute as an "electric power automobile". There is also the costly matter of road tax. I will need to buy a block of 'kilometres' on the Road User Charges system. Because I will no longer be paying taxes through buying petrol, I have to pay road tax based on the weight of the ute and the amount of kilometres I travel. I don't really mind paying that, but it reinforces the impression that there is absolutely no official encouragement of electric vehicles in this country. A bit sad really...

Adrianne and I spent the rest of the day running around town getting the bits and pieces for satisfying the items on the list. I think we have anything now, so I suspect I know exactly what I will be doing over the coming Queens Birthday weekend. At the end of a big day, I am relieved that the ute has rolled one step closer to being a legitimate and bona fide vehicle on New Zealand roads. But this little ute will be a little different, since it's powered by a wind turbine or hydro-electric station somewhere in the National Grid.

Breaking in the batteries

2008-05-25T00:30:00.000-07:00

Trip meter @ 51 km, so I drove 29 km in the ute today.

I just drove down to Harwood towards the end of the Otago Peninsula. I stopped in for a while at the home of my former colleague Mike Stewart. I took Mike for a tiki-tour around Harwood township to show the conversion off. Mike was an important figure in the conversion because it was his MIG welder that glued the motor mounts and battery racks together. I borrowed his welder for 3 months solid. I am not sure quite how the conversion would have gone without that MIG welder. It certainly made my decidely rusty welding technique look spectacularly good and saved a massive amount of time during the crux of the conversion.

His Baby Austin restoration is going well, chassis together, suspension mounted, gearbox and engine installed, steering complete to wheel. He now has the body to build out of aluminium, working from cardboard patterns.

The trip down to Harwood was also to test the new brake booster system. The good news is that enlarging the hose from the vacuum reservoir to the booster to 10 mm diameter, and by connecting the vacuum reservoir directly with the booster, the ute now has very good brake function. And it's all good news since the brakes performed faultlessly through the twisty road down to Harwood. I wish I could say the same about the rear spring suspension. Stiffening up the leaf springs for the weight of the rear battery pack was great for curing the droopy tail effect. However, the stiffness was pretty tangible while driving through the roadworks and the more undulating road surfaces beyond Portobello. I had to keep reminding myself that the road noise is all the louder in the absence of the engine noise. My dodgy carpentry on the drop sides was squeaking, a lot.

The other thing noisy was the booster pump. I am getting use to it, but almost every use of the brake is accompanied by an answering drone from the pump lasting about 5 seconds. It's going to be hard explaining that to people at the traffic lights in summer with the windows down...

The batterypack and controller performed flawlessly on my more extended trip. The controller was barely warm when I popped the bonnet half way through the trip. Maybe the big heat sink and dual cooling fans are doing their job well? The Curtis State of Charge gauge showed just on half empty charge at the end of the trip. I'm hoping that I get more range for what was effectively a flat, widening drive with two repetions of three hills. Time will tell once the batteries are broken in (whenever that's going to be?).

Great trip. Nothing fell off. Ute returned under its own power! The next test is the compliance inspection, hopefully this week coming.

Start the Trip Meter

2008-05-19T01:51:00.000-07:00

Well, the ute is finally an EV.

This weekend (17 & 18 May), the test driving of the ute as an electric ute began. I did a run of 6 km down to Broad Bay with Adrianne following in the Corolla (in case the trip was eventful). It ran really well with good acceleration. The motor seems quite powerful when you get used to the quietness of it. It am still a bit tentative about accelerating because the current spikes up. The system is capable of 500A. However, I decided to set the traction system up with a 250A circuit breaker. Even though the breaker is a slow blow, I get worried whenever the ammeter current sweeps towards the 300A.

The ride is surprisingly good. The weight balance must be reasonably good because the ute corners well and comfortably. Because there is virtually no engine noise, the sound of the transmission is accentuated. Gavin Shoebridge found the same when he started driving his EV sedan. There is no apparent vibration from the coupling, which is a huge relief because it was very difficult to test this before installation and is potentially very difficult to fix it if it developed.

I ended up putting 22 km on the trip meter, including an equivalent trip on the Sunday. The charger did its work admirably both times and the Curtis State of Charge meter seems to give really good indication. The batteries will take a few more tens of kilometres to break in to the point that they begin to deliver the full range potential.

The only problem encountered was the electric brake vacuum boost system. The boost simply isn't there. The brakes are there, but the pedal pressure needs to be quite harsh to do the same job. I visited the local mechanic, Russel, in Macandrew Bay. He was excited as a schoolboy to see under the bonnet. When I first pulled up there were a couple of guys admiring a vintage car outside the garage. They looked puzzled at the ute, perhaps because it was making no noise. I told them it was battery electric, and immediately thought that might be a mistake because one of the guys looked as though he was going to give me a clip for being cheeky. I had to quickly jump out of the ute and show them under the bonnet, and it was all smiles after they saw the truth. Russel came out and looked the vacuum pump plumbing that I had done. His verdict was that the hose diameter had to be also double the 6 mm to allow the diaphragm chamber to take a decent gulp of vacuum assist. So, that's the next job. I'm currently looking for 10 mm diameter vacuum hose.

Once that's sorted out, it's time for the certification inspection.

The Last Major Items

2008-05-14T02:27:00.000-07:00

The last items have gone into the ute conversion now. In the oblique photo above the item that catches the eye is the on-board charger, a Zivan NG3-15. The charger is wired directly to an AC charging plug set just behind the cab. The charger is connected to the battery pack with 6mm2 twin cable and an Anderson 50A connector. On the advice of Mike Laba, I fused the positive of the charging circuit with a 32A high rupture capacity (HRC) fuse link in an industrial fuse holder. It is largely protection against a short-circuit on the charging side.

The blue cylinder in the foreground is a recycled LPG bottle that has been pressed into a new life as a vacuum resrevoir. The vacuum pump is just visible alongside. The vacuum pump and reservoir are now joined in the same vacuum manifold with the brake booster. The vacuum pump is truly noisy, and I am sure it will really irritate me. It evacuates the system and a vacuum switch shuts it down once brake boost is attained again.

There is still a fair bit of tidying to do. Adrianne has managed to buy 50 battery terminal covers for a dollar each to cover up the exposed brass terminal clamps you can see in this shot. The battery clamps are shiny and pretty, but won't stay that way if I drop a Crescent across the terminals and set off a plasma fire as the batteries discharge through the handle of the Crescent.

The torque arm is in place between the chassis and the adaptor plate to oppose the turning force on the motor under acceleration. I have also 'pinned' the motor case to the motor mount with a 7/16 inch UNC bolt.

The instrumentation in the form of the Westach voltmeter and ammeter have gone into the dash either side of the speedo. The Curtis 900R battery State of Charge meter is mounted in the dashboard to the right of the steering wheel. I must get you a photo of that. Seeing them there makes it feel like a real electric ute.

The new Pirelli P3000 tyres are great for improving the roll of the wheels. They seem to have reduced the heaviness of the unassisted steering too.

I love the new Zivan charger. The battery pack got its first charge since the battery dealership in October. They had self-discharged slightly, as you would expect. I turned the charger on and it went into its battery analysis mode straight away. This was shortly followed by the three stages of charging. After equalising, the charger simply shut itself off. The State of Charge meter shows full charge. As simple as that.

With a few adjustments the ute is ready for a test drive, possibly this weekend.

Time to Bring Us into the Present

2008-04-22T02:04:00.001-07:00

It's about time to bring this blog into real-time conversion time. It's also 29 March since my last post and I have been letting it slide to get a decent burst of work on the ute.

Just before Easter I drove the ute in EV mode for the first time. Don't get too excited the journey was merely from the carport into the garage. I chose a strategic period when my father was out of the country (visiting the fair city of Perth) to evict his car from the garage and put the ute there. The cold weather is starting and it seemed to make the shift under lights and under cover.

The power up went smoothly (mostly). I did the recommended test from the Curtis manual, placing the drive wheel axle on stands and powering up the traction circuit in stages. When I first applied 144V and I was testing voltage around the controller area the coil on the contactor made a loud crack! Did I jump out of my skin! I couldn't shut off the circuit fast enough I was so convinced the gear was going to melt down in front of me. It turned out it was just a minor tick from being exposed to voltage for the first time in ages. The potbox circuit worked well, 12v - 144v controller relay functioned perfectly, contactor pulled in and controller drove the motor. Next I put the gearbox into 2nd and repeated the proceedure. I was overjoyed that the rear wheels turned in the right rotation (you never know ...). Next, I selected reverse and drove the wheels in reverse. So, it was time to drop the ute off the wheel stands and drive it EV-style.

I have to admit to being pretty nervous. Yes, I forgot the let off the hand brake at first try. Yes, I should have pumped up the tyre before hand (they were a bit soggy). Yes, the brakes were draggging a bit from, I think, rust. What was that wierd space-age noise from the controller? But, it was moving! I have to admit that when you have been in the thows of the EV conversion obsession, there are times that you can't quite believe that the object of your labours will ever move again under its own power. Seems straight-forward on paper - throw away engine, fit motor, fit batteries and wire it all together. The task is so big that sometimes you honestly wonder if it will come to a useful end.

Anyway, there I was driving the ute along the driveway under electric power and I am apparently grinning from ear to ear. The impulse delivery was very smooth. It's similar to a very smooth automatic without the over-run. The throttle only delivers as much push as you ask for. I was really impressive. I was prepared for a certain jerkiness or unevenness, but the opposite was closer to the truth.

Once in the garage, I have begun a reappraisal of a few matters that have been bugging me. First is the battery terminal connections. I am simply not happy with the low profile lead cast terminals that Exide has supplied the batteries with. They essentially have a stubby lead terminal post of only an inch high. A plated steel stud is cast into the post and when I tight the cable lug onto the top of the post it felts mushy, as if I am pulling the stud out of the post. i have asked around and virtually everyone, including the EV Discussion List, agrees that I need to fit each terminal with brass clamps. A trip to the local automotive electrician, Harrex Downing & Little, and I have 48 brass battery terminal clamps with a 3/8 (M10) stud that I can attach my cable lug to. The bad news is that I need to re-make 21 new battery links as the existing ones won't fit with the new clamps. There is at least three days of work steadily cutting cable, crimping on lugs, heat shrinking sleeves behind lugs, cleaning terminal posts, fitting clamps and connecting links. But, at the end of it I am much more happy. Every time I tighten down the bolt onto the lug I hear and feel that satisfying sound that tells me it's properly tight.

I have also been working on the rear leaf spring rating. After a few measurements, I take off the leaf springs, drop them off at Brown & Cope in McLaghan St and they re-set the springs, including fitting two thin leafs. The result is impressive. No more droopy back end with battery weight in place.

I have just fitted Pirelli P3000 low rolling resistance tyres all around. They are intended for commercial vans and have a weight rating of 850 kg each tyre, so they exceed the rating I needed. I found the whole process of finding low rolling resistance tyres fairly difficult. Virtually no tyre dealer had RRC data on their tyres, or even recommendations on what to try. Bridgestone's B380 for the Toyota Prius is available in New Zealand and is known to have good rolling resistance, but it would not fit my ute nor have the weight rating I needed. The Bridgestone Multihawks would work, but again I would have had to compromise on rim size or tyre profile. Many thanks to Martin Reeves of Bridgestone for doing research for me. Tyreland did not have specific information and could not supply the Vredesteins that I had found out about. But they were able to supply the Pirellis.

Next was the question of the A2 motor lead. This is a connection shown on the Curtis controller circuit diagram from the A2 terminal to the motor. The Curtis 1231C / 1221C manual showed the connection. However, Ross Webster had run the motor without it and Mike Laba didn't use it with his Curtis 1221B. I tried to find out from Curtis Instruments Inc, but they have been swallowed by a larger parent company and communicating from New Zeand to America was not proving easy. However, Justin on the New Zealand Electric Vehicle Association technical group site clear up the mystery. The A2 connection is merely for dynamic, plugging braking and should not be used in road going EVs.

I have received my new Zivan NG3 15 amp on-board battery charger. I ordered this through M & H Power in Auckland before Christmas. I already knew that there was a world wide shortage of Zivan chargers, so the wait for delivery was not unexpected. M & H Power's Melbourne-based technicians set the charger up for my battery pack and voltage. The Zivan is a smart charger that applies full battery pack voltage to the main positive and negative. Especially as an on-board charger, this makes charging a lot more convenient. I will run a triple-insulated 240V AC to the charger from a weather-proof plug behind the cab.

Getting on the road is getting much closer.

More Wiring

2008-03-29T01:09:00.000-07:00

More Wiring and back to the controller again. This is a Curtis 500A controller. It is the link between the batteries and the motor and without the controller running the motor from the batteries would be a fairly wild ride. If you just connected 144V for the battery pack to the motor would just lurch up to full RPM of around 7000 RPM. I expect a bit of rubber would get left behind as you did a fairly good impression of a burn-out. In fact, you can hook up 24VDC to any series motor and drive slowly around with it under ON / OFF controller. Gavin Shoebridge couldn't resist the temptation to try out his new motor straight after he fitted his (see video). So, the controller is needed to feed the battery power initially with low voltage and measured pulses in response to your accelerator (gas pedal) instructions. So, the controller needs a transducer to translate your accelerator pressure to a signal the the controller can understand. This is a potentiometer or pot-box, such as the Curtis PB6 shown below.

It is essentially a cheap 0 to 5000 ohm variable resistance transducer mounted in a stainless steel box and bracket. The pot-box has a swinging arm to connect the accelerator cable. With the accelerator pressure off the swinging arm rests on the left and responds to cable action by moving to the right. That's perfect for left hand drive cars such American EVs, but in right hand drive New Zealand we have to mount the pot-box up-side down or loop the accelerator cable over on itself to achieve the right action.

A small detail really. I just looped the accelerator cable over for my American PB6. A pair of wires goes to the low-voltage terminals on the Curtis controller. The New Zealand certification guideline as requires us to fit a second, independent return spring in case the main return spring breaks.

The controller also needs a separate feed to a lock-out terminal. this feed is controlled by the low voltage 12V system, but actually switches the 144V. The diagram below shows the circuit if you are used to tracing circuit diagrams.

If you follow the diagram, you can see the keyswitch relay prevents the controller from operating without the ignition key being on. Common sense really, but it is another layer of fail-safe protection in the system.

Cabling the Beast

2008-03-23T01:00:00.000-07:00

This EV will have two wiring systems;

144V traction circuit
12V control and accessory circuit

The first system drives the ute. Even though it is operating at a higher voltage, the currents applied in the traction circuit are respectably high. With the motor driving the ute along a flat road the battery circuit current should rest at about 50A. That is the sort of current that a house would use with every conceivable appliance running at the same time. Going uphill or at high speed, the motor currents approach 200A, that's 28 kW for short bursts. In even shorter bursts, short circuit currents from the battery pack are truly scary, potentially up to 1000A!

The traction circuit needs to be wired in heavy cable, preferably flexible cable for ease of cable installation. Flexible welding cable is ideal and most commonly used. I also got earth clamp cable from a scrap merchant (Rietveld's in Stone St). The sizing for the cabling of the main traction circuit is 70 mm2 (2/0 American Wire Gauge). I was able to obtain 70 mm2 cable and 50 mm2 cable, but not enough of the larger size to do the whole circuit. So, the negative side of the rear battery pack to front pack cable run is two 50 mm2 cables doubled together to give a combined 100 mm2 capacity.

Despite the fact that many EVers cable their EV as though it is a low voltage circuit, I need to observe the IP56 insultation pronciples for the traction circuit since the voltage exceeds 48V and is therefore a medium voltage system in terms of electrical licensing. I placed all cabling in exposed sections within PVC conduit or flexible PVC conduit rated at IP56. This achieves 'double insultation', meaning that if one layer of insulation fails, the next one should.

Importantly, the traction circuit is entirely isolated from the vehicle frame. While it is OK to use the ute frame as the earth return for the 12V circuit driving lights and indication, it is definitely not OK to bring any part of the frame in contact with the traction circuit voltages. So, the traction circuit is a simple series circuit with the positive running up one side of the ute and the negative running down the other within the insulated cabling. The diagram below shows the schematic wiring layout.

The traction circuit is shown in bold black and runs through the traction battery pack, power wiring fuse, main contactor, KSI relay, controller, motor leads and back to the negative side of the battery pack. All of these lengths of cable would be carrying the full voltage and applied current of the EV. This all means that the cable and all of the connections made in the circuit experience the full current of the driven EV. Just like the NASA space program, no-one wants there to be a weak link! If there is going to be a weak link we want it to be the protection devices. In the Courier, we would have the following high current protection:

500A power circuit fuse on the positive side

250A electro-mechanical circuit breaker

250A slow-blow fuse on the negative side

"Fuses are your friends, have lots of them"

These are designed to fail without damaging the wiring. Fuses are your friend in protecting the EV traction assets such as the motor, controller and batteries. These pieces of equipment are the highest cost ticket items of your conversion. If you are going to make an idiotic short-circuit or unexpectedly run a very high current, better to replace a $20 fuse or sheepishly reset the circuit breaker than to need the replacement of a $3,000 item on the high ticket list.

Along with the cables, we need solid connections. Each traction circuit cable was terminated in a 70 mm2 size crimp lug. This is a crimp lug below.

The copper core of the cable is put in the round barrel and then a higher pressure (usually 8 ton) crimping tool is used to crimp the cable and lug together in a fused block. The flat drilled tab is used to bolt the lug to the connection at battries, fuses, controller or motor terminals. The EV would need about 65 of these connections to be well made and for then to have low electrical resistance. Not one of these connections is allowed to develop high resistance or become a heating hot spot. The fear is that a connection that goes bad like this will become a run-away failure and damage some gear on the way to completely failing. Just remember, that we are wiring a circuit to run at currents that would normally be used in arc welding.

Battery Racks Are Go

2008-03-15T02:29:00.000-07:00

The first act of constructing the rear battery rack was fitting a flatdeck tray. The shots above show a lot of folks giving me a hand to lift on the pre-prepared flat-deck. They are:

Mike Laba
Pat Hyland
Bob Jones
Sam Hyland
Jack Rekker (my Dad)

A flatdeck is a known as a tabletop in Australia and somewhat more common in New Zealand and Australia than anywhere else in the world, from what I can tell. Importantly for me, a wood-decked flatdeck tray is a lot lighter and has a maximum dimension slightly wider than the cab. The benefits of the change from the wellside tray to the flatdeck tray was the lighter weight and the ability to tuck 18 batteries in two rows immediately behind the cab. Other EVers converting utilies, including Mazda B-series utes and Ford Rangers, place their battery pack under the wellside tray and get access with a tilting mechanism from the rear. Maybe they are smarter than me, but I could not see any workable way of doing the same with mine. So, I opted to have the batteries half sunk onto chasis mounts and emerging through an elongate hole in the deck. I would build a box and lid around the battery rack. You can see this hole in the bottom shot above.

The rear battery rack proved to be simple 1640 mm by 540 mm rectangle of heavy gauge angle iron (L-section) with a bisecting rib of angle and flat iron down the length of the rack. This provided the double row of 6V batteries a firm platform. This base rack rested directly on the two front chasis mounts and the flat-deck mounts are arranged slightly fore and aft of the rack. Two independent struts take weight from the centre of the rack and attach to the left and right chasis rails. The following shots attempt to show the detail before the battery box was built around it.

Side view.

Top view. The basic idea is that the batteries are half sunk into the deck level to get the weight optimally low and have an uninterrupted layer of batteries just above the range of movement for the drive shaft. The main battery weight thus rests at the centre of the vehicle rather than over or behind the rear axle.

The whole rear battery pack is tied down with four 4.6 m loops of high capacity tie-down strapping and tensioning ratchets. The total tie-down breaking force should exceed 2,000 kg in horizontal and vertical planes using this system. The minimum tie-down breaking force requirement is 1,350 kg, so there is a good degree of safety factor built in. In addition, a steel and ply-wood box was then built around the rack and batteries. Access is provided by a tilting box lid built out of angle iron, aluminium plate and insulating ply-wood (on the inside of the lid).

The rear battery box and the flat-deck preparation before it took a lot of time, probably three weeks of continuous work. This delayed progress towards EV wiring, but hopefully turns out to be a substantial benefit to the finished EV. Credit for the basic idea of arranging the battery pack in this way should go to Mark Hazen who published it in his EVHelp.com website. The shot below shows his (much tidier) rack design for his Chevy S10 truck conversion.

The from battery racks hold only six batteries, four in front of the motor and two to the left of the motor. Individual tie-down straps rated at 400 kg were used on each of the six batteries in the engine compartment.

With the batteries in their place it was time to begin wiring the syste together.

Connecting Motor and Drive-train

2008-03-15T01:00:00.000-07:00

This is a cut-away of series wound DC motor of the type that would be going in my ute. In the old, old days of EV conversions they salvaged aircraft starter motors and forklift motors for the main electric drive. The voltages were down around 48VDC or lower and the speed very limited as a result. In the 1980's 72V forklifts started to be common, and more importantly, some went beyond their useful life allowing EV enthusiasts to scavenge the higher voltage motors for higher performance EVs. Along came purpose-built Prestolite motors, which were a slight advance. Advanced DC Motors Inc in the 1990's lived up to its name among the EV community, and the company even made some consessions to the small but growing EV motor market.

My motor was a 1994 vintage Advanced XP-1263 rated at 144V and up to 500A (if you were very brave to take the current up that high). I don't know the full history, but appears that the XP-1263 at 8-inch diameter was a transitional design on the way to the more popular FB-4001 in the 9-inch housing. I have also read of it being described as experimental. In any case it is no longer in production and regarded with affection by some for its power to weight ratio, and derision by others for its habit of exploding if used in reverse rotation for Honda conversions.

The motor weighs about 60 kg and is about 600 mm long. It looks small and anaemic alongside the original petrol engine, which does not bolster the confidence that it can deliver the same power, torque and speed.

This motor needed to be coupled to the gearbox in the same way that the petrol engine was. I decided that I wanted to retain the clutch. There is much discussion, even controversy, among the EV community about whether it is better to keep the clutch or discard it, going for a direct coupling instead. I won't go into the arguments other than to say I see both sides' advantages and disadvantages. Nonetheless, I decided that if I could keep my clutch and the automotive engineer was in agreement, I would opt that way.

So, we have a motor that was never designed with the idea of coupling with an automotive gearbox on one side and a gearbox that was intensively designed to be coupled with a crankshaft on the other. Mating the two was stepping into pioneering territory. There were EVers that maintained it was an easy task and finished it in a day with an aluminium plate and something called a Lovejoy connector. I wasn't so confident, so I took them to a precision engineer with experience in both forklifts and jetboats. Sounded like the perfect combination of skills, so I asked Adrian Mulder in Concord to make the connection. I took the gearbox and motor, plus the clutch and fly-wheel up to his workshop. Five days later he presented me with the finished product.

What you can see in the photo is the motor, the adaptor plate and above it the clutch mounted on a flywheel. Most importantly, the adaptor plate, the flywheel and the clutch plate are perfectly aligned and dimensioned to slide onto the gearbox. To say I was pleased and relieved with Adrian's work would be a huge understatement. I was ecstatic! Suddenly, only days after the removal of the engine, I had the very heart of the EV completed. Almost all of the conversion work radiated out from dimensions of the motor and gearbox. With the coupling finished I could start on the motor mounts (I would be retaining the original gearbox mounts), set my front battery racks and finalise the position of controller and other wiring.

On the technical side, the adaptor plate had to be milled down from 32 mm (1-inch and a quarter) thick steel plate. The original flywheel was discarded after measurements were taken and clutch plate mounted on a lightened 6 mm plate. The clutch was not going to get heavy use, nor was the inertia of a thickened flywheel required to prevent a stall as for the petrol engine, so a lightened flywheel made perfect sense.

In subsequent weekends I made up a motor mount using steel plate and angle iron. This held the motor in the correct position and alignment and clamped it to prevent the turning reaction under power. After the petrol engine removal, the motor installation was an anti-climax. I simply lifted the gearbox onto the mounts from below and stabilised it with a trolley jack. Then I bench-pressed the 60 kg motor on the bottom half of the motor mount. A bit of wiggling and I had the clutch slid over the gearbox's input shaft and the adaptor plate hard up against the bell-housing. A few minutes bolting up the bell-housing and motor mount clamp and it was done. I should have taken pictures, but my hands were a bit full at the time ...

In this shot you can see the motor coupled with the bell-housing and the brown motor mount clamped around the motor to support and stabilise it. You may be able to pick that the motor mount is built to mount on the original rubberised engine mounts. I had also started the front battery racks by this time. The long front battery rack just fits in front of the secondary shaft of the motor.

So, just before Christmas 2007 I was ready to start the battery racks, especially the voluminous rack behind the cab that would need to carry half a ton.

De-Gassing the Gasser

2008-03-14T23:41:00.000-07:00

EV enthusiasts, I learned, called a petrol or diesel vehicle a gasser. I had been driven / had driven "cars" all my life without thinking of them as gassers. Suddenly, I was exposed to a world where there were alternatives. So, I had to learn some new language, such as ...

A petrol / gasoline car was a gasser and therefore to be scorned,
An electric car was an EV and to be treasured,
A car stripped of all of its petrol gear, or de-gassed, was a glider,
A car being considered for conversion to EV was a donor car.

So, this post is about de-gassing the gasser. It's quite straight forward really. You take out what defines the car or ute as a petroleum fuel vehicle and keep those things that will help you make the conversion while keeping the vehicle road-worthy. The list of things to take out is predictable:

The petrol motor,
The petrol tank,
Fuel lines,
Radiator and hoses,
Ignition coil circuit,
Exhaust system.

The things joining with these items that you keep are further:

Gearbox and drive-train,
The clutch and fly-wheel (if only to take measurements from)
12V wiring system,
Lots of useful clamps, fixings and brackets that you will definitely use in the conversion.

So, it is really a very common place backyard scene as you yank the engine etc. The major difference is that they are never going back in and ute will never sound the same again.

I hired an engine hoist and a trailer for yanking the engine. The process only takes a couple of days, but it has a certain psycological and symbolic value. I used my Haynes overhaul manual and the chapter covering engine, clutch and gearbox removal. It was a very messy business with lots of sticky, potentially hazardous and difficult to dispose of fluids. I ended up lying on my side in a pool of petrol spilling from the petrol tank drain plug. It stung my skin all down one side and the clothes I was wearing have never smelled right since.
Out came the exhaust -

Out came the radiator -

And finally, out came the motor -

I took the gearbox out at the same time since my next task was to carry out the couple of electric motor and gearbox. A current topic of advanced discussion in EV circles seems to be direct coupling of the motor with the differential, or even individual axles, thereby losing the weight of the gearbox. However, that raises a series of complications. The first is the gear reduction that the gearbox provides. The next is the loss of gearing. It is technically feasible to have the electric motor covering all RPM ranges and the forward / reverse shifting electronically. However, it turns a mechanical set of complications into electrical complications. I had already decided to follow the path well trod by converters before me and use my gearbox to good advantage.

The engine went on the trailer and was sold for a miserable $100 the next day. That was despite the engine being sound and the auto dimantler having the chance to hear it running before I yanked the motor. Oh well, the country is saturated in used cars and used car parts, so it's not surprising.

It felt strange to have an empty engine bay on the second day of the conversion. Part of me was saying "you idiot, that was a perfectly good ute you just ruined". Another part of me was soothing those fears with "you know what you're doing, you're already committed, you can see this through to a running ute again". I wasn't sure which side was winning in the coming days ...

Those batteries

2008-03-12T01:30:00.001-07:00

Yes, you're looking at deep cycle lead acid batteries. The one on the right is the Trojan T105 6-volt golf cart battery. The one on the left is a chinese clone called an ED105 and manufactured to the same specification as the US manufactured Trojan battery. No guesses as to which one is cheaper! And you guessed right if you thought I bought the cheaper chinese clone. All joking aside, Trojans have a cast iron reputation as a high quality, strong deep cycle battery and the ED105 reproduced the basic specification of the Trojan very closely. So, I was able to buy Champagne at Lager prices.

Both the ED105 and T105 have a 20 hour power storage rating of 215 Ampere-hours (Ah). At the battery's 6 volt nominal voltage that means the battery stores up to 1.3 kilowatt-hours (kWh). My 24 batteries means the 'battery pack' stores 31 kWh when daisy-chained together in series. This gives me a voltage of 144 V nominal, or approximately 150 V as an open-circuit standing voltage. This is the power plant or fuel tank of the EV. In general, kWh power storage capacity provides the range and the voltage dictates the top speed with acceleration. My EV will have both good range and the highest voltage available to my controller. This comes at a cost in weight.

The ED105 batteries are slightly heavier than the Trojan T105, weighing in at about 30 kg. I wasn't complaining about the additional 2 to 4 kg over the T105, since lead weight equals range. The heavier the lead weight, within limits, the greater the range. However, the combined battery pack was going to add 720 kg to the ute.

This view shows 18 batteries installed in the rear battery pack behind the passenger cab. This represents 540 kg of mostly lead. However, the weight is well centred and in front of the rear wheels. So, the range trade-off is weight. All the same the ute can take the weight and one bonus is that the petrol motor and associated gear was coming out!

Finding the right battery combination proved to be a major worry for me during the planning stages. The conversion needs to be designed around the battery pack, so it is necessary to settle on a particular battery dimension and specification. I seemed to be endlessly juggling factors of battery chemistry, type (flooded, AGM or Gel), capacity, weight and cost in deciding on the battery pack. In the final analysis I settled on the fact that I had good payload capacity and my batteries outside the cab in a fully vented situation. So, I might as well go with flooded batteries. These have some of the best cycle ratings of any lead acid battery type, typically 500 of more recharge - discharge cycles are feasible from flooded deep cycle batteries. The next consideration was the Depth of Discharge (DOD). DOD is expressed as a percentage of full charge (100%). If you use the battery capacity to within 20% of empty, then you have discharged 80% DOD. The shallower that your EV running dips into the DOD pool the longer that your battery pack will last. So, if you are consistently dipping deep into the battery capacity down to 80% DOD or worse, you are unlikely to get more than a few hundred recharge - discharge cycles. Conversely if you do a small number of kilometres and recharge at every opportunity, the battery pack might last up to a thousand cycles. One thing became clear and that was if you set your battery capacity very close to your expected daily use then you would routinely dipping deep into the DOD, shortening your battery pack life and paying for a new set of batteries in quick order.

So, flooded batteries made sense. The next choice was voltage. Remember that the target voltage was 144V. So, 12 x 12V batteries gave the nominal voltage. However, 18 x 8V batteries or 24 x 6V batteries give the same pack voltage. I saw that higher ampere-hour rated 12V batteries were individually quite large and heavy, not to mention expensive. Other converters found 8V and 6V battery voltage configurations more workable. I saw that a 6V battery with about 215 Ah gave an individual capacity of 1.3 kWh. Multiply that by 24 in a series circuit and the combined pack capacity added up to 31 kWh at 100% DOD. The basic range calculation for electric vehicle range is give as follows:

Range(km) = 250 x capacity(kWh) / mass(kg)^0.6

Where:

EV Mass = 1500 kg

Capacity = 31 kWh

So, by plugging those numbers into the equation, the maximum range that pops out is 96 km at 100% DOD. I would have a reasonable commuting range of 50 km or so without dipping far into the DOD capacity of the battery pack. Of course, the range is dependent on a vastly wider set of variables. To help you look at these variables someone has provided a really smart calculator that is already seeded with those tricky parameters of weight, rolling resistance, battery performance / capacity, controller efficiency, aero-dynamics and incline corrections. The address is as follws:

http://www.geocities.com/hempev/EVCalculator.html

It's fun to play with this or the EV Calculator Tool at www.evconvert.com just to appreciate the sensitivity of these variables. But it's not cool to spend hours testing different configurations, which is tempting, but would be time better spent getting onto your conversion (if that's what you've decided to do).

Donor Ute

2008-02-21T23:24:00.000-08:00

This was the last task of the ute before the ICE was taken out of it. There were some deep cycle batteries to be picked up from Exide Batteries in South Dunedin and delivered to the family workshop in Macandrew Bay.

Unfortuntely, the ute was a bit camera shy in the lead up to the conversion and the photo on the right is probably the best shot of it that I still have. Opposite on the left is a stylised profile shot of the ute from the Haynes Mazda Pickup manual. The ute is a 1989 Ford Courier, essentially a Mazda B2000 clone re-badged to the Ford label in New Zealand and Australia. By now you will have compared the shot on the left with the photo on the right and noticed that the steering wheel is on the right hand side in the photo. Putting the wheel on the right is just the way we do it in New Zealand.

The ute originally had a big, fibre glass (composite) non aerodynamic canopy over the tray. That was the first thing to be taken off. The ute then spent a few weeks hauling broken concrete and clay fill to the landfill as I dug out the garage in order to deepen and widen an old garage built with accommodating a Mini in mind, rather than a ute. Both hauling the clay and delivering the 720 kg of batteries reinforced the impression that it was comfortable with carrying a significant battery load. Come to think of it, the ute also hauled about 1000 kg of wet cement from the batching plant to the garage up the second steepest street in the world (we live a block from the actual world's steepest street, Baldwin Street).

Best of all the ute has a Gross Vehicle Maximum (GVM) of 2300 kg and a curb weight prior to the conversion of about 1420 kg, leaving an impressive payload allowance of 880 kg. Second best feature was the lack of power steering. The safety certification requires me to restore all of the existing systems during the conversion. If the ute had been fitted with power steering I would needed to replace the power steering actuator with a range-sapping electric hydraulic pump. On the down side, the steel wellside tray you can see bearing the batteries was very heavy. I pondered over whether to keep the wellside tray or not. In the end I took the suggestion of a US ute converter, Mark Hazen ( http://www.evhelp.com/Conversion_Tips.htm ), and decided to ditch the tray. I thought I should be able to replace the tray with a lighter weight wooden flat deck tray, so off it came.

The First Parts Arrive

2008-02-18T00:51:00.000-08:00

This is what I got in the post at the end of September 2007. In case you're not sure what's actually in the photo, here's a list:

A DC electric traction motor, it's pedigree is XP-1263A for Advanced DC Motors. It is rated at about 28 HP continuous (100 HP peak). The maximum voltage is 144V and current rating is about 500A, i.e. 72 kW at absolute peak power.
The stripy black box is a Curtis 144V, 500A controller to operate the motor through its whole RPM range.
In between is the main contactor, a few protective fuses and the current shunt to drive the ammeter.

This formed the core of my EV conversion. They were all second hand parts bought from a EV converter in Auckland. They apparently originated from a VW Bettle conversion done in the US during the 1990's. Some folks might notice that the motor was already fitted with an adaptor plate, flywheel and clutch in the photo. I couldn't use these as they were (of course) designed for the VW conversion, including genuine VW clutch parts. I briefly considered buying a VW Bettle donor car to take advantage of the adaptor parts.

The immediate task with the motor was to find a way of coupling the transmission of my donor ute to the bolt pattern of my motor. The motor and gear box shafts had to line up perfectly to avoid the bearings in each side burning out through chatter. The offstand distances between transmission connections and the motor also had to be precise. I had read about US converters doing the gearbox - motor connector and adaptor in a couple of days using only an aluminium plate, drill press and something called a Lovejoy coupling. The more I looked at the task, the more I realised that I needed an engineer to do the job.

Before sending the gear down to me, Ross sent a short video showing the motor and controller operating together. It was reassuring to get this as I was buying second hand parts from a distance. Ross had a 72 volt DC power supply from his electric ute, and used this to power the controller and motor at no load. Notice the 'squeal' as the motor starts up each time. It's due to the frequency pulse modulation of the power electronics (MOSFETs) that are at the heart of the Curtis controller. The squeal is also very characteristic of the 144V Curtis controllers.

Early Days

2008-02-06T01:21:00.000-08:00

What do you need to do to convert an ICE to EV?

I soon found out that there were three broad kinds of Electric Vehicles (EVs) in the world:

- Production EVs (GM's EV1 was a production car until production stopped in 2002)

- Non-production EVs produced by car companies (prototypes, proof of concept cars)

- Backyard conversions (now very few commercial conversions are done)

I would fall into the last category. That meant that I would take a vehicle that was intended to be powered by an energetic petrol engine and retro-fit an electric system. The sad fact staring me in the face was that hydrocarbons (petrol, gas, diesel) are wonderful fuels. They have the power and weight profile to give us a fanatastic energy density for a portable power plant that a vehicle is. Replacing the petrol motor with most other sources of portable energy is going to result in giving away something, usually either power or range. In the case of most battery EV conversions you lose both power and range. You generally lose a little acceleration and top speed. But most of all, an EV conversion from petrol to battery power drops the achievable range to a quarter of what it was before. There are only a few feasible ways of getting that power and range back (if only partially). They are:

Make the vehicle as light as possible (rip stuff out),
Make the energy density (energy to weight ratio) of the battery as high as possible (select high energy density batteries, if you can afford them),
Make the vehicle as aerodynamic as possible (aero-mods),
Make energy and power losses such as rolling resistance and transmission drag as low as possible (changing to low rolling resistance tyres, light transmission fluid or fixing brake drag).

None of this is easy if you are doing a conversion from an ICE powered vehicle. The compromises and trade-offs for weight and drag have already been set in the body and drive train of the vehicle concerned. The underlying assumption is made in the original design of the vehicle that the vehicle posesses an energetic motor with the power and energy storage that petrol can provide. The vehicle is certainly a better compromise than most mortals such as I could devise without the decades of adaption of a competitive auto industry. But the EV conversion is usually locked into a heavier body, set body shape, conservatively designed drive-train and large range of accessory features than one would want if you were looking for the perfect EV donor vehicle or starting from scratch.

Fortunately, electric motors are substantially more efficient than ICE power plants. ICE energy efficiency can be roughly apportioned as follows:

Exhaust losses 33% mostly as waste heat and noise energy
Radiator losses 33% mostly as waste heat
Radiant losses 10% as waste heat
Actual motive energy 25%

This is the reason that ICE powered vehicles need water cooling jackets, heat shields and mufflers. Even with all of these inefficiencies an ICE car with a full tank of fuel can take five people 500 km at 100 kph and spend only five minutes refueling before doing it all over again. EV motors are closer to 80% efficient and develop maximum torque from low speed. ICE power vehicles develop most of their torque from the mid area of their RPM range. This is the reason that ICE vehicles need flywheels, coupled with manual or automatic transmissions and reduction gearing in order to smooth out the mis-match between when the torque is required on take off to when it is available for the engine. Ask anyone learning to drive a manual transmission ICE about trying to make the optimum torque match on a hill start using a bunch of pedals and levers simultaneously!

So, electric motors have the advantage of high efficiency and torque where you need it. This allows them to be much smaller and lighter than an ICE. That's just as well, since it frees up some space to accommodate more of those heavy batteries!

Enough theory. I wanted to find out how practical this all was. My first tack was to investigate buying a Generation II Toyota Prius and fit an expanded battery pack with plug-in charging so that I could travel further than 2 km on pure EV mode around town. At first this appeared to be an elegant solution allowing me to have the environmental warm fuzzy feelings of driving EV around town while having the range, speed and power of petrol if I chose to travel out of town. Closer investigation revealed that this was feasible using only the most energy dense batteries (US lithium iron phosphate prismatic cells) and would probably cost NZ$50,000 when the Prius, conversion and battery costs were added up. It is also doubtful if the New Zealand authorities would safety certify the modification due to the weight problem over the rear axle. More on weight restrictions later, but just to note that the Prius is already very close to the weight maximum due to cramming an ICE, generator, electric motor and battery pack into a small car. Besides I was getting a dose of EV fire in the belly where anything less than full EV was a cop-out! So, lets look at the EV options further:

A light-weight aero-dynamic hatch or sedan converted with sealed lead acid batteries,
A medium size car converted with sealed batteries, or
A light ute converted with flooded batteries fitted outside the passenger compartment.

You can see that I was already narrowing the options down to a few complimentary configurations. I had been learning about backyard conversions from sites like EvAlbum. I had also had time to learn that New Zealand had developed a safety certification guideline for EV conversions. Two of the hot points in the guideline (and consequently how I was going to be scrutineered) were weight and battery placement. Placing the batteries in anywhere considered the 'passenger compartment' (including the back of a hatch or sedan) had to pass over a much higher bar than if their were placed outside compartment. Recharging and discharging flooded lead acid batteries emits gases, including the potentially explosive hydrogen gas. At 20 kg to 30 kg each, the batteries are also lethal projectiles in a roll-over or other crash (imagine a half dozen batteries of that weight rolling around in the car with you at the same time in a roll-over!). The safety certification guidelines specified that you needed to tie the batteries down to restrain 20 times the battery mass (= 600 kg tie-down force for each 30 kg battery!) and provide the battery compartment with a completely different atmospheric venting system if in the passenger compartment.

I studied the real-life experience of EV converters working under these constraints and saw that they had to compromise by reducing the battery storage capacity (thereby decreasing the range) and often lost the ability to use the two back seats anyway because of weight constraints. Any vehicle for EV conversion has two critical weights:

Gross Vehicle Mass (GVM), the maximum weight of vehicle and payload, and
Curb Weight, the weight of the base vehicle without passengers or other contents.

The conversion can not exceed the GVM and needs to start with the Curb Weight. In most non-commercial passenger cars the gap between the curb weight and GVM is not much, greatly constraining the additional weight that the conversion can add. This factor was the second one (after battery containment) that began to tip me towards a ute as the donor vehicle. With a ute, the batteries would be entirely outside the passenger compartment and thus required no more containment than the standard starter battery of an ICE vehicle. Without the containment restrictions and atmospheric venting, the conversion could use non-sophisticated flooded lead acid batteries. Whats more, the GVM of commercial utes is usually twice the curb weight meaning that the weight constraints were effectively removed. I could fit as many deep cycle, flooded lead acid batteries as I pleased, constrained by the power to weight balance rather than the rating of the chasis.

I looked at overseas (mostly US) EV conversions and noticed at the same time that "light trucks" very similar to the utes available in New Zealand were found to be successful conversions to EV. In particular the Ford, USElectricCar and Solectria companies had produced successful lines of converted Ford Rangers and Chevrolet S-10 "pickups" to EV power. These professional conversions numbered a few thousands in the US from about 1995 to 2003, but tapered off dramatically with the removal of the Zero Emission Vehicle mandate by the California Air Resources Board (see Who Killed the Electric Car, which briefly mentions EV Rangers in connection with the fight over the ZEV mandate). Backyard converters during and after this period also followed this niche of EV conversion approach with some EV parts suppliers virtually specialised in "pickup" conversion components (EV America is now foremost among these). This all cemented my thinking towards utes. I saw that Ford Rangers, Toyota Pickups and Mazda Sundowners were popular choices in the US with local equivalents. The Toyota Hilux 2WD, Ford Courier and the Mazda B2000 were all available here, and I narrowed my search down to these.

I wanted to constrain the cost of the conversion to something half-by reasonable, and the obvious place to start being frugal was with the purchase of the donor vehicle. Toyota Hiluxes are generally more highly valued as second hand, so I restricted myself to older Hilux and the less popular Couriers and Mazda B2000s.

In the midst of selecting a donor vehicle I discovered that I wasn't alone! By that I mean that I found out that there were other EV converters in New Zealand. Gavin Shoebridge in New Plymouth was on the way to becoming an Internet and media star with his Mitzubishi Tredia conversion and website (www.kiwiev.com). I also found Ross Webster selling Xebra EV utes on TradeMe out of Henderson, Auckland. It turned out that Ross had made several Fiat EV conversions and was just backing off from the idea converting a Fiat X1-9. He still had a second-hand motor, controller, contactor and other gear for sale. I quickly avoided the need for importing these items and the associated shipping costs by settling a deal with Ross. Suddenly, I had much of the components for the conversion arriving at the door.

Soon after I was test driving second hand utes. It was a weird experience to be totally unconcerned about the condition of the ICE engine. Usually, these parts are the most expensive to fix if they are worn. But instead I was obsessing about the body condition, transmission and valuing the lack of power accessories such as power steering and air conditioning. The owner of the Ford Courier, that I eventually bought, was quite puzzled at how excited I was that the ute didn't have power steering, especially since this lack was the reason that he was selling the ute in the first place.

So, I was finally in posession of the two most important features of the conversion, the donor vehicle and the electric drive system, in September 2007.

Beginnings

2008-02-05T23:52:00.000-08:00

This is a story about converting an ordinary old petrol powered (read 'gas' for N America) ute (= utility, pickup, truck) to 100% electric power.

The seed for doing this was how inspired (and more than slightly worried) I felt after going to a talk by Tim Flannery (scientist and Australian of the Year 2007) in June 2007. He came to my home town and gave an eye-popping account of the crisis that the atmosphere is in with the human induced CO2 and other green house gas rise in the global air-mass. Tim impressed on us that the time to "de-carbonise", that is reduce the amount of green house gases our economy / life style gives off, was NOW. Waiting 20 years was too late to get carbon emissions out of the system, global climate change will have already irretrievably hit the green house gas concentrations necessary to trigger the tipping points and positive feed-back mechanisms to make the global climate change really, profoundly destructive of the planet. I had heard a lot of this before, but there was something about hearing it delivered by a passionate person that carried real strength for me. What could I do after a message like that other than walk away, say "wow, that's heavy, too big a problem for me, maybe the government will do something about it"? Strangely, I seized upon the idea of doing an Electric Vehicle (EV) conversion. But let me explain.

New Zealand is a small country with a small population (about 4 million, still outnumbered by sheep). Surprisingly, New Zealand has developed a power supply rich in renewable sources that don't emit green house gases, even before it was fashionable. Hydro(-electricity) is the back-bone of the national grid with a system of hydro lakes and diversions on the rivers of both islands (imaginatively named North Island and South Island). Geothermal is also a significant minor power source. The real growth source for electricty is wind power. There is a modest amount already installed, but there is also 2000 MW wind power capacity in advanced planning or authorisations. The fossil fuel power sources on the national grid are natural gas and some black coal. These thermal power plants are for peaking load and when the winter power demand is high and the hydro lake have small inflows with the winter freeze. Over 70% of the country's power is produced from renewables and that proportion is only set to increase with the phase out of thermal plants (there is a moritorium on any new fossil fuel power plants) and ramping up of wind and geothermal plants. The take-home message is that New Zealand uniquely has ample power resources that are largely renewable (as long as the clouds rain and the wind blows) with minimal green house gas emissions in generating it.

New Zealand's big-time green house gas emissions are from internal combustion engines (ICEs)and the methane emitting from both ends of our sheep and cattle. I'm not a farmer, so I can't do much about the belching and farting of methane from farm animals (neither can a a farmer, I guess). But, I am a driver. I've been an enthusiastic driver or rider of ICE vehicles since I was 15. In the course of driving around the country and around my home town, I have put countless tons of CO2 in the atmosphere, plus particulates, carbon monoxide, nitrous oxides and ozone that pollute the city air. This was something I could do something about.

This is where the EV conversion comes in. I could either stop using ICE vehicles altogether (cold turkey) or I could get around the in a vehicle that did not emit green house gases. The logical choice would be walking or a Human Powered Vehicle (HPV), i.e. a bicyle. I can do that for some of my trips, but 100% is too hard (meaning the behavioural shift is too challenging, I'm a whimp). I had heard about electric cars and seen the Who Killed the Electric Car video that same year, but it was 10 second segment in the film that caught my attention. The Who Killed the Electric Car film had a quick flash showing an EV converter fitting batteries into an american car. The converter said something like "people bring cars to me, I rip out the engine and fit a full electrical system for them to drive around in". I watched that video four times! That was an interesting concept. I had some idea that it could be possible to revolutionise my mode of transport for a couple of thousand dollars.

I did the research on the internet and found a lot of real information out there. Before I knew it, I had taken one of my vehicles, ripped the ICE engine out and got rid of it. After that I was fully committed!

The rest of my blog describes the conversion. Beginnings gives you the background.