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If you had it to do over what would you do different?

7561 Views 22 Replies 21 Participants Last post by  Ziggythewiz
I'm still in the idea phase myself and trying to learn from other people's mistakes. Maybe find a common mistake people make and avoid it. So what would you do differently? This could include, not do it at all, or buy an already made one from chevy or nissan, or nothing at all!
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1) Agree with prior post that the cheapest glider isn't going to be the best. I spent $400 on my MR2 but another $2000 or so on just chassis repairs (brakes, paint, etc) If I had been more patient I could probably have gotten a good chassis for less than what I spent rehabbing it, and certainly also saved time in the process

2) Use lithium. It wasn't economically feasible for me when I built my car, but it is now and so unless low initial cost is your only concern there is no reason to be going with a lead acid battery pack today.

3) Insulate your battery pack, or at least leave enough room on the top, sides, and bottom such that it is possible to retrofit insulation as needed. This may be less of an issue with lithiums but they are still susceptible to cold temperatures and even 1/2 inch of builders foam insulation will help substantially to retain heat.

4) Don't scrimp on wire sizes. We all know not to undersize the main battery and motor cables, but using smaller size wiring for secondary circuits such as for the charger and other loads may lead to needing to replace the wiring if for example you go to a more powerful charger in the future. For example I originally ran 20A rated extension cord from my charger's output to the battery pack which was fine while I had a russco charger, but when I upgraded to a manzanita I had to re-run all that cabling and upgrade a bunch of fuses and terminal blocks. Depending on the car and the layout of components this may not be a big deal, or it could be a major pain.

4) Leave room for upgrades. This goes for all major components. Your current charger/controller/whatever may fit perfectly in that nook/cranny under the hood but the replacement / upgrade one a few years down the road may have to go under the passenger seat or force major rearrangement of other components if you didn't leave enough room. Of course if you have a small chassis and a big battery like I do, you may have to make compromises.

5) Leave maintenance access. I have to put my car on ramps to get at the motor controller since it is mounted low in the car which is a bit of a pain. If you can place things where they are easier to get at, it makes maintenance much faster, cleaner, and easier. Of course again if you have small car and big battery like I do you may have to compromise here.

6) Favor weight over aerodynamics. I computed for maximum efficiency at freeway speeds when I was designing my car and selecting a chassis. However typical EV conversion usage has a lot more local stop and go type driving where a reduction in overall weight is going to be more beneficial than a more aerodynamic chassis. Note that using lithium batteries would be a major improvement but even then a sleek 2500lbs chassis is probably going to get worse wh/mile in an urban setting vs. a less-sleek but lighter 2000lbs chassis, especially if you have hills to deal with.

7) If you are not looking to build a high performance car, seriously consider one of the low-voltage (relatively speaking) HPGC/Curtis AC systems. For not much more than an equivalent sized DC system you get the regenerative braking (especially bonus-ful if you have hills) and reliability of an AC system. Tradeoff is you will be limited to a 108v battery pack meaning bigger cabling and cells to deal with.

Good luck.
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I would start with a vehicle I loved and and do it for the fun of it.

I would not plan to start with someone else's ideal car and then try to make it fit my requirements for my commute.

If I was to go back two years and give myself some advice it would be to go back six years and not sell my late brother's MGB that I had restored for him. It would have made a great conversion and I would have had reason to love it all over again and not keep it as a rotting memorial to our racing youth.

Otherwise I would look for a classic British car, MG, Austin Mini, Mk1 Escort, and convert that.

I would still build my tractor as that is a lot of fun for learning on but at the same time I would convert an old, simple, mechanical (not electronic) car that I loved.
Use a newer car (as opposed to the old Bug I always wanted). Electrical issues have been very rare and set me back at most 90 min. Mechanical issues have been common and set me back up to a month.

DIY controller and charger. Greater flexibility, lower cost. Saves some money for lithium, or a ton of money when switching to lithium.
I am doing it again.

This time I went with a good, running chassis ($3500) and lithium batteries, and max voltage. My first EV was a cheap donor that work decent, but not my favorite (4dr Civic sedan). I also choose the lowest voltage I could get away with (96 volts) and found most of my parts used.

This time I am using a donor I love (2dr Civic EX), going with at least 144 volts of 180 Ah Lithium and going to put emphasis on performance, not price tag. The savings from going to cheap to quality just isn't worth it in the long run. Quality lead acid batteries are only good for 7-8K miles these days, which lasted me two years, but I was not driving constantly because of used part failures and the pack wasn't sized for winter use.

I drive about 10-12K a year, and I really only need 40-50 miles of range, but I'm aiming for 100-120 miles back roads to have a good buffer.
This is all very helpful information as I am beginning to plan a conversion myself. I have an older classic american car and the performance/price/distance dilema is what I am trying to figure out.

I have a donor car I definitely love as it was the first car I ever owned.

Keep the lessons learned coming!
If I had to do my conversion over, I would save the money and buy a production EV. My project is eventually for everyday commuting, so having a 25+ year old car with no A/C in SoCal wasn't the best choice. When I made the plunge it was still pretty borderline about whether the Leaf and Volt would actually make it to market.

If I did an EV conversion again just as a project, then I would find a cherry 66 Mustang Fastback and put 200+ Volts of 200AH Lithium and an 11 inch motor in it. Its a heavy vehicle, but that should give some decent power and range.
Even though I have yet to make an EV move under its own power: :rolleyes::)

If I had it to do all over again, I wouldn't change one single thing about what was done, or how it was done, with the Inhaler Model E. I have loved the entire process, and am pretty much hooked on electric because of it. Though it probably seems like it's never going to happen, and never going to be a reality, we're really excited about our plans for the next two years with it. It's coming...

The one thing I would do different on a more personal note, as that project was always a business marketing tool, is I would have built a motorcycle project and/or hybrid car project sooner. I might have even started there first. Something that either I don't need for anything in particular and/or doesn't depend on the electric drive for the main source of motivation. I have the hybrid car project underway now, and I am seriously tempted to convert my newest (Ninja) motorcyle project to electric. For my personal projects, I think it's more enjoyable to remove all the typical demands (range, power, space, etc) and just build what happens to work, and enjoy it for what it is. Woody's Tractor is the perfect example. It doesn't have to meet any specific demands, and has been one of the most fun projects to follow on this forum - probably ten-fold for him. I still can't believe he made me like a tractor! :p:D

If I wanted an EV for a driver, or any practical needs, I would buy a production EV.
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For my personal projects, I think it's more enjoyable to remove all the typical demands (range, power, space, etc) and just build what happens to work, and enjoy it for what it is. Woody's Tractor is the perfect example. It doesn't have to meet any specific demands, and has been one of the most fun projects to follow on this forum - probably ten-fold for him. I still can't believe he made me like a tractor! :p:D
Glad to be of service.:D
i guess I'll be the exception... i wouldn't do anything different! Though I've only been driving my EV for a few months, I may sing a different song when summer hits and I have no air conditioning in my car. :eek: Though, I never had air conditioning in any of my cars until I was almost 30 and got married. I think my kids are a bit soft anyway, they could stand to suffer in the heat a little bit. :D

Anyway, I went into it with the mindset of it being a functional hobby. I bought an already converted, but needing work, car. I've now got a car that cost me about 1/2 of a production EV, has about 1/2 the range (yet plenty for my daily driving needs), and a resale value of maybe 1/2 of what I put into it. It's been fun, and I like that it's low tech and I can work on it.
I started with a 1990 Ford Ranger extended cab pickup. I got the conversion kit from Electro Automotive. I wanted it to get the best range so I wanted regenerative braking- that is why I went for an AC power kit.

So far its been a disaster! It took a while to assemble the vehicle, and on completion it was found that the controller was dead in the water. Azure Dynamics filed for bankruptcy a couple weeks later. Electro Automotive apparently is terrible at answering phone calls, email or responding to FAX so no help from whatever expertise they may or may not have on staff- no way to even know.

So if I had it to do over I would stay away from them for starters!! 2nd, its no good to get greedy. You are probably better off going with the most popular hardware as you will find more support. I wanted a vehicle that would go about 100 miles; on paper what I have will do it but in practice it has a lot in common with a rock- one that so far has cost me over $20,000. If I had settled for a 40-50 mile range I probably would have been driving for a while now.
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my initial build was 96v FLA w/ Curtis 1221 and 8" ADC in a Suzuki Swift. Thats all the lead I could fit and it could carry... barely. Pb batteries were fading badly after 7000 miles or so and I upgraded to 120v of 100ah Li; WAY better.

I will never build another with Pb.

120v is all that is recommended for ADC 8", and 8" is all that will gracefully fit in my donor. next time around though I would CONSIDER bumping voltage up to next common value supported by chargers and using a Soliton Jr controller to limit the voltage the motor actually sees. I have physical room for a couple more cells, and could bump the pack voltage (and total energy available for range) by taking advantage of a 'modern' controller like the Soliton.

I would strongly consider Soliton, or perhaps Synkromotive controller rather than old standby Curtis controller.
Even if you think the car you have is in good shape, make certain. I had the roller and I have spent 1/2 of my build time just fixing the problems. If I were to start over I would spend money for a copy of my car that has a lot less miles on it. Under 50k if possible and certainly under 100k miles. The same things apply as if you were buying a used car except that it isn't necessary for the ICE to run. But if it doesn't that could be an indicator of abuse in other areas. On my next build the car will be in great condition when I start.
Just completely forget about using a @#$%@#$ brushed motor. You will have nothing but problems. Have you ever hear of a part that works worse when new than old?? How about switching brushes and needing to run the car/plane/boat on blocks for a week??? ABSURD! Whats that frying sound? Oh, that's the new brushes. Just friggin great. Motor overheating? Prolly just the @#$# brushes again. Worthless junk. Not getting the range you should. Blame those @#$#$# brushes. Again and Again and Again it is the same story. Blown motor? don't worry, just the result of using completely outdated tech.

Brushed motors are dead. RIP.

Ok, you know what my week was like...
I've built 3 EVs. 2 of them retained the clutch and I got rid of both of them. No more clutch, perhaps 2 motors and direct drive next time. Others will disagree, feel free. :D
I would have not tried to cleanly cram all my stuff into the engine bay only. I would have utilized some of the rest of the storage space in the car on order to make working on it all easier and less cramped. I thought it would be nice to retain all the original storage and seating of the original car... but now I realize no one ever sits in the back seat, and the space in the boot is never used and is pooly sized for anything but a breifcase anyway. Locating my charger up there would have certainly saved me a dozen headaches.

I would have labeled all my original wiring before disconnecting it from the OEM motor.
I would go with lithium, a larger motor and a more powerful controller.
1. Definitely pick a vehicle you will actually want to drive when you're done. No point putting all the time, effort and money into a cheap beater chassis that you got for free but will be embarrassed to drive when you're done.

2. Consider that your project could take you a few years to finish, what position will you be in your life in 2 years? Will you still be living the same distance from work? I started the mini truck in 2010 and now my wife and I have a young son. Awesome, but now the mini truck is done and if we want to go anywhere as a family I still have to take my ICE car!

3. Don't reinvent the wheel, it's been made many times already and there is usually a reason it's done that way. Start with a basic conversion and once you have some experience then try some experiments with new ideas. Those motor adapters that cost $800 will seem like a deal once you try to build one yourself. (unless you have easy materials and machine shop access)

4. Start with a running licensed vehicle that has already passed any safety inspections you need to drive it. Getting an out of province inspection on a right hand drive Japanese mini truck that had never been licensed in Canada and had been converted to electric drive was a challenge! Applying for a change of fuel status for an already registered vehicle is easy (all that's needed in Canada).

5. Drive the car as a gas vehicle for a bit, do you like it? Chances are it'll still be the same vehicle when you're done, just slower, and heavier, but electric powered! Are there any major issues with the chassis that you will have to resolve? They will likely still be there when you're done.

6. Now something I did do that I would do again. Consider doing the conversion with a friend, you can share work space, tools, costs and even the vehicle in the end. Car sharing is right up there with EVs in terms of eco cred. Something like a truck conversion is great for sharing as a truck is something that most people don't need every day. If your friend is within biking distance that makes getting together to work on the project and dropping off the vehicle a piece of cake. Sharing the work and costs is what made this project feasible for both of us. Working with a friend is also a lot more fun, easier (moving heavy parts) and safer (someone to call 911 when you electrocute yourself!)

Have fun!
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I'd definitely do it again and not change too much.

  • Nowadays I would go straight to Lithium
  • More gauges (volts, amps, motor temp, field current, etc.) This would have saved me from cooking my 1st motor (admittedly it was run hard and I had a hard-to-detect controller problem)
  • Smarter charger
  • Great father son project -- I'm also teaming with a high school to help them with electrathon
  • Posted more pics and details about what I have done online
  • Taking it to an environmental car fair, a car show, and the Salt Flats has been great fun. Once my Lithium is in and going reliably I'm looking forward to autocross and maybe even some time trials on the road racing track.
  • Spent a little less time online and more wrenching on the car
  • Maybe a little less time engineering and more building
Be realistic with your budget. It's probably going to cost more than you originally thought!

Go with Litium right from the start.

Over estimate your usable range requirements.
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