[Planecrazy]

Hiya, Ben!

I have spent the last three days reading through your EV exploits from start to finish, this a result of having seen your instructable. To say I'm impressed is a major understatement! It's impressive enough to undertake what you have and complete such a project (to the point that you have) in so little time with so little money invested, but to do so (and succeed) in the brutal weather we both experience here in the upper midwest is truly commendable!

I see you have made the trek into IL a number of times to attend EV and alternative energy events. The next time you find yourself headed for the Chicago area I'd sure love to know about it so I can check out the Electro-Metro! My best friend (who lives in Zion, just south of Kenosha) is intent on building an EV recumbent bike (which I'll help him weld up) and I'm sure he'd also love to check out both of your EV machines!

I had a thought regarding your defrosting challenges for winter driving. It occurred to me that if you were to build a removable shroud that captured the heat coming off the motor (and perhaps utilized the airflow generated by the integrated fan) you might be able to get a nice constant supply of fresh, heated (even if it's only slightly heated) air funneled to your defroster vents. A side benefit (at least during the winter) is that such a shroud MIGHT also help to muffle some of the "futuristic cougar" noise coming off the motor and make the Electro-Metro even quieter than it already is. I suspect that the amplitude of your EV isn't an issue at all, but it would be cool to make the "cat" even slinkier than it already is, hehe!

I know you've mentioned that the motor generates almost no heat, but I suspect that with the increased voltage (and even at the lower 72 volts) that fan is (or will be) probably moving a meaningful amount of warmer air. Wouldn't it be great to be able to use that excess "free" energy to keep the windshield clear without losing any electrical efficiency in the process? I realize this doesn't solve your overall heating problem in the cabin, but it does provide one possible solution to the biggest problem you've had driving the EV in the winter ... seeing out the windshield!

Another possibility would be to suck warmer air out of the transmission housing (using the access hole cut into the bottom) to perform the same task. This assumes two things that may or may not be true ... First, that the operation of the EV causes the tranny to heat up enough so that you can use that excess energy and second, that any heat built up collects inside that housing such that you can use a small fan to blow it into the defrost vents. This solution would, of course, require you to add a small electric blower to the equation, since the tranny doesn't have an integrated cooling fan like the motor does. However, if the tranny gets warm enough during operation it might be worth the trade-off to harness that heat energy.

I also have an observation regarding the question of the Electro-Metro's gross vehicle weight (GVW) capacity. You've been basing your plan to either use or dump the back seat based on GVW figures for a stock Metro, but just like a full sized pickup truck can be bought with several different load ratings (mostly based on suspension differences) you've substantially changed/upgraded the Electro-Metro so that those original figures don't necessarily apply anymore. The combination of beefier springs from the Explorer/Ranger combined with the addition of a sturdy battery box in place of what was originally contoured/flat sheet metal in the body has hypothetically upped the structural integrity/load carrying capability quite a bit.

I would argue that if you added a few well placed pieces of square tubing to the equation (to tie the battery boxes and frame pieces together in addition to the sheet metal that already does this) you could confidently carry a much heavier load than what the original specs dictate. I'm not, of course, suggesting that you go out of your way to overload the vehicle, but I want to make sure that you realize that you've probably added quite a bit to the vehicle's GVW capabilities. In short, I'd keep the back seat simply because you never know when you might wish/have to squeeze a few extra passengers into the vehicle, and I believe it is more than up to the task of handling the increased load, at least for short hops.

Hope these ideas are useful! I've truly enjoyed following your progress, and look forward to someday meeting you (and the other EV guys/gals) and seeing the projects in action!

Regards,
Steve