Greg,

If it's any consolation, you are definately not alone. The dreaded battery decision is what is frustrating and delaying many EVers I expect. I'll be doing a similar project with similar expectations (Miata). I won't need quite the acceleration you're looking for.

Your lucky in that your daily commute is short enough that you could use lead without adding tremendous weight that would require suspension and brake upgrades.

I really want to convince myself that lithium is the way to go and perhaps even a good investment vs. lead. The worry is as you suggest, what if they don't last 8-10 years?? It raises the questions; should I start with lead, then switch? should I delay for a couple of years till lithium or a successor is proven?

No one knows the true long term performance of the new chemistries (calendar life, cycles, DOD issues...). Plus, it seems pretty unlikely that there will be any kind of meaningful warranttee, at least for a bargain priced cell.

Sorry I don't have a useful suggestion or solution! Where do we go from here? I keep hoping that a large group buy will be arranged that will address the issues of cost, reputable supplier and warranttee. I know what I want, I just can't bring myself to spend $20+K on batteries!

Rob

 

You can expect lithium batteries to last as long as they do in your cell phone, which is only a few years. Not suitable, in my opinion, for EV use except high-end applications where life expectancy is not a serious factor.

NiMH technology in EV-size packs may become available to the public if and when controlling patents eventually expire, or not, since, as a suppressed technology, NiMH would be difficult to obtain in any event, as it is now, unless something better came out by then, but that is in the future and this is now.

So for now, most EVers will have to make do with lead. Which is ok. It is heavy, but it is cheap. You get relatively lots of power for the money. Yes, the weight brings up chassis, suspension and brake issues, but they are solvable in a way that still makes a cost-effective, useful car more than possible.

 

Thanks for the replies, ya'll.

I've seen examples online of people who've converted Ghias/Bugs who've used 10 12-volt batteries of various manufacture. Probably my likely scenario. That'd give me 120v to play with.

I will also investigate front-ending a lead-cell power pack with some super-capacitors to give me a few seconds or so of "turbo-boost" to get my off-the-line acceleration and still enjoy the cost benefit of lead cells.

Does anyone know how I can learn what chassis or suspension improvements may have to be made to a Ghia to handle 10 batteries? I suppose it depends on what batteries I choose, but heavy-duty deep-cycle models could add 700-800lbs to the little car. I can easily put heavy-duty adjustable shocks on the car, but what else should I consider?

Greg

 

It's hard to compare Lithium in a Cellphone as compared to them in an EV. You'd thave to figure out how many cycles that Cellphone is racking up during those few years of use.

We are on the last leg stage of the LiFePO4 upgrade of the Dallas/Ft.Worth's Electric Auto Association president's Fiero. It made it's first 25 mile round trip voyage to the 2008 North American Solar Challenge race kickoff in Plano, Texas this weekend.

The car performed VERY well, both in off the line performance, no bottoming out at railroad crossings, and the voltage only dropped a couple of volts overall once the initial surface charge leveled out to the pack's nominal voltage.

The bussbars will be replaced to handle the current better, as some were warm to the touch, but not to hot to keep a finger on them. I know John's one of those that will not let that slide, and is looking now for heavy guage stranded flat braided straps.

You can see his conversion in the Fiero Upgrade photo set at:

www.flickr.com/mbarkley/sets

But especially, check out the videos/photos of the kid's cars in the 2008 North American Solar Challenge as well in that photo set. Those kids worked hard on those cars.