The project continues. Way back in late 2010 I began writing about my project to convert a 1986 Toyota Pickup (22R 4spd) to electric drive. (Read here)
Since then, I have gained a few things, and lost a couple. The things I’ve gained are skills and appreciation, specifically appreciation for just how long a project like this takes. Like any other automotive endeavor it can sit for weeks or even a month and the only things that have been added are piles of junk that festoon what should be an object of pride. It’s most certainly a work in progress.
Oh, and what did I lose? a couple zeros from the checking account here and there. (Don’t we all?) The main things that have happened since October 2010 were engine, bed, and gas tank removal. The engine was removed with help from a neighbor who I located through Craigslist. He has to be the best neighbor ever. He wanted the engine for the crank; he’s got a custom Toyota rig that would make most 4-wheelers blush.
A mechanic and ex-miner with years of experience and tools to trade, he is a great local resource and is intrigued by the crazy thing I’m doing.
After all the “removals,” it was time to add stuff. All four corners got new shocks. The rear was a little bit of a different story, I fitted pneumatic shocks and also beefed up the rear springs with load springs. I also re-used the original tail lights, fitted to a 100% custom crossbar bracket. It’ll do for now.
Battery box welding
The next big step in the build was to actually decide where the batteries will go and make it a reality. I had some crazy plans for a lop sided battery box that would have space for 16 batteries and avoid some clearance issues with one of the shocks. After careful consideration I decided to KISS and simply squeeze in 2 rows of 8 right next to each other. (I’ve seen a fair few truck conversions that do it that way, and others that put batteries lower to straddle either side of the driveshaft.)
I’d never welded before. The tail light bracket was my first attempt and I was pretty impressed. So what did I do? I thought I’d have a crack at perhaps the most critical load bearing structure on the truck. Obviously. It’s worked out nicely so far with 1.5″ eighth inch angle and flat bar. I even ended up with a nice space in the center for cables and fans. Careful consideration was given to where the original bed bolts go through the bottom frame of the box; they should sit neatly under the batteries that will be sitting on some sort of aluminum sheet and styrofoam.
The recent big job was a couple of reinforcement struts that go at about a 30 degree angle down from the center crossbar to welded nuts on the truck frame. It’s delicate work for an inexperienced person wielding an angle grinder, welder and a calculator. Yes, I broke out the trigonometry.
Hopefully these cross beam supports will compensate for any flex that the two main beams may experience. When I first put them on the truck I noticed about a quarter inch of flex when all 180 lbs of my weight was applied. Now that they are bolted to the towers that held the bed in place, they don’t really flex; they can’t pull inwards. With the addition of the lower supports they’re pretty darn solid. 1200 to 1300 lbs solid? We’ll see.
The inexpensive way, hang on did I mention I’m cheap? The inexpensive way to crimp cables is with a sledge. A die set really helps though. Hydraulic crimpers are also a great option, you can rent them too, but I decided on the quick and dirty route.
The 2/0 (2 aught) welding cable is beefy stuff for shifting some serious current. The post style of the batteries I have isn’t the best, but it’s gonna have to do. Many prefer the automotive style posts for larger contact area and no risk of over-tightening and pulling out the stud from the lead post.
Vacuum Pump & Tank
One of the simplest and cheapest items I added to the truck quickly was the beginnings of the vacuum brake assist system to replace the vacuum of the engine. Simply a vac pump and a reservoir that hook to the brake booster. Essential stuff for safety considering all the extra weight. I may also consider a booster size upgrade in the future. (Thanks to Tim Catellier for selling me his old pump!)
Battery Temp & Future Cooling
One of the things driving me nuts right now is that I have received some free batteries, wait no, that part is awesome. What sucks is hot garages. Arizona, as I’m sure you’re aware, is no friend to car batteries. Higher temperatures ensure the self-discharge rate of a stored battery really goes up.
These are the batteries I received used. I have 12 of them which, in series, gives 96v. It will be enough to make the truck move, but performance will not be great. The final aim is 16, for 120v They all tested pretty good – about 8.4 to 8.5v – but I really hate to have them sit in a hot garage.
I have been periodically charging them with solar panels to ensure they really don’t fall below 8.25v, but it’s depressing work because they’re simply being cycled for no good reason. At least it’s “free” energy. All is not lost though because, when I buy a new set, these are still worth some dough; between $10-15 is a usual recycling core charge, so that’s $180 off a new set.
So you’re going to subject new batteries to high amp draw and horrific summer temperatures? Yes. The life of a lead acid battery in AZ is a torturous one. This is a big concern of mine and it’s been compounded by the fact it is now July. Battery box cooling is an engineering problem I have to conquer. A couple of different ways I might achieve cooling would, for starters, be just straight fans, moving 20-30 CFM through the box in and out, that’s the cheap way.
Another option is a small heat exchanger of some kind, basically AC for the box. Liquid cooling could get complex, but it would probably be the most effective.
“Clean/free” energy to take care of cooling and accessories; the truck will eventually have a PV (photovoltaic) panel mounted above the battery box. It will be juicing a charge controller, charging a 12v deep cycle accessory battery or two.
These will provide for the lights, radio, vac pump, main contactor coil, eventually an AC system, and most certainly the cooling for the batteries, whatever that system ends up being. The main challenge with solar panels, though, is their energy density.
For a fairly larger surface area, you don’t get that much power, comparatively. Cell efficiencies in the 10-15% range dictate a panel from the last decade measuring approximately 4.5ft x 2.5ft that nets you about 150 watts. That’s not a lot to spread around for all those systems I mentioned. It will be quite an experiment. (Although I also have a 220watt panel to experiment with.)
An even more fun experiment would be to charge the main pack with such a setup, as I’m doing now with the batteries hooked up in 24v packs in my garage. It would probably take about 6-7 days to charge the entire pack so you could drive 45-50 miles. A new perspective on energy? Of course the strength of solar is in more than one panel… not on the truck.
All in all, the project is going well. Not in leaps and bounds, but at a slow and steady pace. I feel work might speed up once the weather cools down. Most of the upgrades to the original truck have taken place, and a big step in the battery box structure has been built. Yet to do immediately are replace the transmission mount, and yes… buy a motor!
Until next time, stay plugged, my friends.
We haven’t had much in the way of EV conversions lately, but we know there are still a few EV enthusiasts visiting the site and reading via RSS. While the majority of this site is stories of people with gas guzzling performance cars, we love sharing stories of EV conversions. As gearheads, we can all appreciate the time and effort that goes into any well thought-out automotive project. If you’ve got an EV conversion – in-process, on the road – or know someone with a cool project we should talk to, please let us know. We will follow up with them.
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