Charging at College - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

vpoppv · 09-01-2010, 05:30 PM

I keep thinking about asking Oklahoma State University about putting in charging stations, but it's not like I could ever use one: I'm 30 miles away at 65mph the whole way. That's when the gas Geo becomes necessary....

bennelson · 09-01-2010, 06:25 PM

Current battery configuration only allows for a max speed of 45mph. I don't think aeromods are going to make that big of a difference. I'm really not interested in doing a boat-tail or anything on it.

One thing I actually rather like about the car is that it looks pretty stock.

I either need more batts, or the generator.

The other possibility is to take a different vehicle.

The electric motorcycle has better range on it than the Metro. It weighs about a third as much, and is running on new, instead of used batteries. However, it's still not the best vehicle for cold, rain, snow, and deer.

Tweety · 09-01-2010, 06:53 PM

As it is you are running none or few batteries up front right? Wouldn't there be some room there to shoehorn in a few more?

vinny1989 · 09-01-2010, 07:30 PM

Ben - Your battery box is where the stock fuel tank used to be, right? Doesn't your 'metro have a spare wheel well, accessed from inside the boot?

If yes, Then cut it out and make another battery box there. I assume you don't carry a spare wheel with you for weight reasons? Even if you can only fit another 2 in there, that would get you from 72v up to 96v..

bennelson · 09-01-2010, 10:12 PM

The car does have a spare tire well. However, the structure for supporting the car and connecting to the back tires all connects together back there. There really isn't a good way to hack that up for installing batteries.

In the FRONT, "shoehorning" might be the right word to get more batteries in there. The problem is that batteries either fit.... or they don't.

You can't squish them. I did some measurements, and it MAY be possible to cram two more batteries in front, but IT'S SO CLOSE!

I wish the hood was flat instead of curved! I think that's one of the reasons that EV converters like old compact pickup trucks - everything is so nice and boxy!

To fit those two more batteries in front, I would have to build a custom battery box or rack. It would have to fit EXACTLY between the motor and the hood. To ever work on the motor, I would have to completely remove those batteries. Not that I ever need to "work on" the motor, but it's nice to at least see it when showing off the cars.

The other thing that I think might help is to at least have multi-battery monitoring. Because they are used batteries, and are in series, the weakest one limits the entire pack. Likewise, when charging, differences in voltage can cause problems in getting a really full charge.

Daox · 09-02-2010, 07:14 AM

You need to test out some of TomG's battery monitors. I got one last week for the mower. They look pretty nice.

bennelson · 09-02-2010, 10:19 AM

Yes, I plan to get some of Tom's battery monitors, I just haven't had a chance to get over there since he got them working. I might be able to go over there tonight, if he's around.

For those who don't know, our friend Tom (who you see in many of my YouTube videos) is an electrical engineer who has a homebuilt AC Dodge Neon.

He's designed some simple battery monitors based on a multi-LED bar. Essentially, it's a real-time, mini bar graph of your battery voltage. Each little pc board of LEDs shows the voltage of 4 individual batteries.

I am also interested in using these monitors in my home battery backup system. Currently, the 48V UPS is using two parallel strings of of four batteries. By using the battery monitors, I can see if any individual battery is bringing the rest of the string down.