Hi all, I’m thinking about an ev commutor project. At $4.20/gal I’m starting to think strongly about it. So here’s my question. I’m wanting something light, maybe a civic or something like that with a DC kit and a 120v batt. pack. I just aquired 10 12v. UPS batteries (Dynasty ups12-370fr). My commute is 60 miles a day on mostly flat roads. Is this doable, or am I way off? Any help would be greatly appreciated.
[QUOTE=mearnest;2779]Hi all, I’m thinking about an ev commutor project. At $4.20/gal I’m starting to think strongly about it. So here’s my question. I’m wanting something light, maybe a civic or something like that with a DC kit and a 120v batt. pack. I just aquired 10 12v. UPS batteries (Dynasty ups12-370fr). My commute is 60 miles a day on mostly flat roads. Is this doable, or am I way off? Any help would be greatly appreciated.[/QUOTE]
The kicker here is how far you cycle the batteries. If you cycle them to
almost dead every time, you’re going to burn them up in short order.
If you want to drive 60 miles every day, you should probably build for
80-100 mile range. That way, as the batteries age, you’ll still get to
work and get home. 
If you build the car for 60 mile range, as soon
as you have any slight battery problems, you’re calling AAA. 
is it possible to build a car with an 80-100 mile range with a DC motor and 10 12v batts?
Oh, yeah, I didn’t actually answer your question. Sorry about that.
The answer is probably not. Not using a production car, anyway.
Check out this post: http://www.evforum.net/forums/showpost.php?p=2780&postcount=8
From the spec sheet I saw for the Dynasty 370, 10 batteries only puts you at about
30 miles range for a small sedan like the Civic. You would need a much, much lighter
vehicle or more than twice as many batteries to come close to your desired range.
Okay, so its starting to sound like there aren’t many viable options to build an ev with that kind of range, without spending 30+g’s. What other options are there? Am i doomed to spend $4.20/gal of gas? lol
[QUOTE=mearnest;2784]Okay, so its starting to sound like there aren’t many viable options to build an ev with that kind of range, without spending 30+g’s. What other options are there? Am i doomed to spend $4.20/gal of gas? lol[/QUOTE]
Your best bet is to see if the place you are going to has an electric outlet. In that case, use it. Unstead of looking at 70mile trip(to be on the safe side add more) you’ll need 35 miles. And 10 batteries of 12V 100Ah could do it.
You could build an even lighter vehicle but that depends on your requirements and any local restrictions.
Example: In my town you could build basically a roll cage with wheels and it would be legal as long as it has lights. The only restrictions are eye protection (or install a windshield) and you have to stay off the highway, but any surface streets are fair game. Because of the light weight you can use smaller motor which makes getting more range from less batteries possible. Here, people outfit their Rhino/UTV’s, Quads, golf carts, sand rails, dune buggies etc. with lighting and more street-safe wheels/tires and suspension and use them to get around town instead of cars.
Unfortunately, starting off with a production car puts you at a big disadvantage as far as controlling costs and maximizing efficiency go because of the weight, but the benefit is you’re legal for all roads and you already have all the safety equipment required by Federal regulations… although a roll cage is pretty safe in its own right.
Yes, I wish work would let me plug in, but I dont see them allowing that. And to the point of using a production car, again I agree. The cars are already heavy, then you throw another 1,000 lbs on for batteries, and sudenly you have a tank on your hands.
I’ll say this, the person or company that gets the battery issue’s fixed will become the next Henry Ford. No doubt about that.
If work won’t let you plug in, taking along a portable generator might be the ticket. One would both weigh less than the extra batteries and likely cost less, and are very efficient compared to a gasoline car engine since the generators are optimized to run at one RPM, the best RPM for the generator. Some of them will burn a quart per hour under full load. If it took the generator 4 hours to do a full recharge, it would be the equivalent of 60-70MPG burning premium fuel when the cost of the home recharge were thrown in.
You can do it, just!, but you need to seriously spec up your battery pack. If you run a 144v system and use 8v batts, around 170Ah, total of 18, you’ll get there with a small, lightish hatchback/saloon, still only if you drive very steadily and carefully, you won’t if you drive it like an ICE car.
Even with this, you may compromise battery life as I expect you’ll have to drive to around 70% dod or possibly a little more to get it, ideally, try to keep above 50% dod max for maximum battery life
telco, will the generator thing really work? have people actually done this?
Sure, there’s lots of folks that have EVs for driving around locally, then extend the range with a tow behind generator. It takes a pretty hefty generator though. The generator would run behind the car on the trailer, and provide power to the battery pack charge controller. I don’t know of anyone who has a generator large enough to provide enough power to run the car on its own though. This is something I’ve been looking into. I figure that if a diesel electric locomotive can get 3 gallons to the mile pulling thousands of tons that an electric vehicle should be able to see super high mileage with the same setup as the engine driving the generator would be optimized to one RPM instead of being optimized to a 5000RPM band. Not having any luck finding a large enough generator to handle the load while being small enough to fit the vehicle though.
But, if you just need a generator to recharge the packs when you arrive to work, then the generator need not be that big. You’d need one large enough to charge the battery pack over a 4-6 hour period, which means you can use a smaller generator that can run longer. The charge controller would start and stop it for you, and you’d come back to the car with fully charged batteries. And, some of the really small generators can run on as little as a quart of fuel per hour. With a 4 hour charge time, that means your 30 mile drive would take 1 gallon of fuel, making the round trip mileage at 60MPG. It probably won’t cost a buck to recharge the batteries at home.
Check around and see what you can come up with though, as the further you can go on batteries the less you’d need a generator. If you do a cost analysis on the better batteries vs the lower cost batteries, generator and fuel costs over a, say, 3 year period, you might find it to be cheaper to just get better batteries that can take you there and back.
Here’s 2 links to check out.
Commercial company discussion on EV range extender
Discussion on different ways to extend range
You can also do a search on “ev range extender generator” for more info.