Hi Ed,
I really appreciate the reply. You have already helped me a LOT! I have a Plymouth Neon that I want to convert to an electric vehichle buy I don’t have a lot of money to accomplish it. The curb weight i have to work with is 2457 and I estimate the engine weight with all the other stuff that will be removed to be about 800 lbs. This will leave me with about 1700 lbs driving weight plus all the electric conversion items. I like your idea of the 144 v components and use 72 volts as I am more interested in range than performance. If I can get 50-60 miles and 35 to 40 mph I will be really happy. I’m also hoping to find other ways to increase both on these forums and other internet sources. My neon has aluminum rims which will help a little. I will be keeping you informed and my friend who is helping me is a professional mechanic with 30 years experience and he has an idea for increasing the range a LOT. If it works I will share it and you can use it in your conversions.
Thanks again, Bill
Bill,
Thanks for taking a look at the site, and congratulations on deciding to convert your own car.
I’m free to offer any help I can while you do your conversion. Let me also say that I am in no way an automotive or electrical expert – but I’ve dealt with most of the obstacles you’ll have to deal with and I can certainly let you know how I worked things out.
I hope you can get started in June also. It took me about 2 full months worth of weekend to get the car on the road. If you start in June, you should have plenty of time to get some driving in before fall.
I’m glad you liked the Exxon letter, it’s even better that your connected to it the way you are. Some love the letter, some hate it – I honestly think people read too much into it. It wasn’t meant to be political, a satire on American business or anything else with any deep meaning – it was just a joke. Nonetheless, I’m happy you enjoyed it.
As for what voltage you should run, that is completely up to you. Depends on what you want out of the car. For example:
Lets say that in the Tercel you can fit a total o f 12 batteries (and that is pushing it). If you run your car at 72 volts, you can have 12x 6volt batteries. This configuration will give you good range overall, but your motor performance will be limited. On the other side of the coin, you could run the car at 144 volts, giving you 12x 12volt batteries. This is going to give you killer performance (expecially in such a small car) but you’ll be trading off range for this performance. It all depends on what your goals are for the car, and what your budget is like.
As your voltage goes up, so does your horsepower (generally speaking). As your horsepower goes up, so does your cars performance AND so does its energy consumption. A Mustang will use more fuel than a Metro. If your goal is to have a show car/toy, I would go for the higher voltage setup. If your goal is to have a commuter car, lower voltage is probably going to be better suited (unless you have a very short commute).
The other option is this, and I wish that I would have gone this route. Buy a 144volt motor, controller and charger. However, start running the vehicle on only 72 volts (6 good deep cycle 12v batteries). The car will run just fine on 72v even though your components are 144v. As time goes forward, you have a lot of flexibility. You can add more batteries in series to crank up the volts/HP, or you can add more batteries in parallel to increase your range. This would work very well if you lived in an area where you have a winter of some sort. Batteries don’t work real well when it gets cold. In this example, you could run the car at 144v in the summertime, then when it begins to get cold, switch your configuration around and run it with 2x 72volt strings. This will help combat the effect the cold has on the battery.
To sum it up, it just depends on what you expect from the car.
If you’ve got deep enough pockets, go with a 500hp AC motor and $15,000 worth of lithium batteries. Then you can have performance and range!
On the contact page of my site there are a number of links to some different calculators that I used. One in particular is evconvert.com. There is a range calculator here that will let you plug in all the information about your conversion and let you know what you can expect the range to be.
If you are looking to get 70-80 miles per charge on lead acid batteries you are going to have a difficult time. I have 6x 12volt batteries and I can get 20 miles on a good day. If I went with 12x 6volt batteries of a very high quality I might get 50 on a good day, 40 on average (summertime temps, winter would half that). 12x 6volts would cost in the ballpark of 2500$ or more.
If you need to get that much range out of the car, I would suggest 1 of 2 paths. If you stick with a small car like a Tercel, your going to have to get better quality batteries – current lead acid batteries simply won’t cut it. I think you’d then be looking at some flavor of lithium to get the job done. If I were to buy a lithium pack to replace my current pack, it’d cost me about 9600$.
If you want to go with lead acid batteries, you may want to look into converting a Chevy S-10 or something similar. The S-10 is a pretty popular conversion. The bigger benefit here is the fact that trucks were made for hauling things. Many people will take the bed off the frame, put 18 or more batteries in between the rear frame rails, then put the bed back on. You are going to reach the maximum weight rating on a Tercel much faster than you will an S-10, so you can really pack the batteries into an S-10. The other thing to consider is weight. You start adding more weight to a vehicle and you then have to verify that it will brakes, steering, suspension and all other vehicle systems work correctly with the added weight.
This is a very good forum: http://www.diyelectriccar.com/. I’m sure your familier with “Gav” from KiwiEV, he’s very active on these forums.
I’ll be very interested to see how things go for you. Whatever the result, it is a very fun project and has taught me a lot. Please keep in touch, I’m always happy to offer any help I can.
Ed
ZeroGasoline Administrator