Ben Nelson's Electro-Metro Build thread

[bennelson]

I pulled 6 of the batteries out of the car today.

I think part of the issue MAY be the series/parallel thing. I looked through the charger instruction manual today and it says that it's for battery packs of 80 to 120 AH.

Running two sets of 100AH batts in parallel makes it a 72V 200AH pack.

Possibly, the charger has an issue with charging the big pack if it can sense the "speed" it charges at?

Oh well, at least by going to just 6 batteries, it eliminates one more thing to make troubleshooting easier.

Of course without those extra 6 batteries, the truck springs jack the back of the car an extra couple inches!

I will be showing the car AND the motorcycle at ROCK THE EARTH in Fort Atkinson, WI tomorrow.

[MPaulHolmes]

Hey Ben! Man, you have tons of events! I only have 1 event the whole year! And, it's supposed to rain. Makes me mad!

[bennelson]

ROCK THE EARTH was fun!

The weather was really good. We had sunshine. My wife got sunburnt! (She is white. Not caucasian. White.)

She and I made the one hour drive in the pickup truck, with the motorcycle in the bed, and towing the Electro-Metro.

There was lots of interest in both vehicles, including by a local radio personality and a professor of ecology from the university. The professor is SERIOUSLY interested in an electric car conversion. I'm hoping I can point him in the right direction to get him going on it.

[bennelson]

I packed up all my gel cell batteries today and hauled them in to Challenger Battery in Waukesha, Wisconsin.

These are the guys who fixed my Optima YellowTop post for free. (Nice guys!)

They are going to charge/discharge and load-test my 18 Deka Dominators to give me a sense of "which are the good ones".

I am planning on stringing together the best ones in the Electro-Metro, keeping extras in the reserves, and recycling any really bad ones.


I also bought a waterbed today off Craigslist. It's the whole thing, including the waterbed heater, which I though would be useful as a winter battery warmer.

The rest of the waterbed is going towards a water conservation project at my house.


PS: The guy at challenger also asked if I was the guy who got the speeding ticket in the electric car that while back. Yes. Yes, I was.

EDIT:
Here's a photo of the waterbed heater. It's almost a PERFECT size for my "back seat" battery box.

I plugged it in to the Killawatt, and it did measure as a 300 watt heater.
The thermostat on it is adjustable between room temperature to about 100 degrees farenheight.

The power for the heater plugs in to thermostat unit, so it would be easy to pull off and wire it to a time instead, or possibly a different thermostat. 70 degrees is really more than needed for the batteries in the winter. They don't need to be room temperature, they just need to NOT be frozen!!!

[MetroMPG]

Are they charging you for charging & discharging?

I'm going to pester you now a little bit: if you had an LED battery pack monitor like these ones, you'd already know which were your best & worst batteries in terms of both "stiffness" and capacity. Having one in your own vehicle is like having constant rolling load testing under the conditions you actually use them.

In terms of instrumentation, I'd say it's actually more important than the volts or amps gauges.

Put it on your to-do list!

Still, it'll be interesting to know what they discover.

[bennelson]

Stop taunting me with your delightful LED bar graph!!!

I have been jealous of that thing for a long time!

The battery shop guys are real nice. They fixed my Optima post for merely the price of "come see us when you want new batteries". I will most likely buy a flooded battery or two from them after this for the Citicar.

Tom, who is building the 300V AC Neon, has a REALLY SLICK built-from-scratch battery monitoring system, that will monitor 27 batteries and log it all to a computer. However, that system isn't done yet, and won't be until after some other work on his car. I am guessing that the monitor system is a year away.

Ryland suggested that I get a PakTrakr. That is about $300 for a system that will handle 12 batteries, including amperage and watts.

I like the idea of it being "turn-key" and it handles a lot of functions.


EDIT: I got a message from Doax. He is interested in an LED Bar chart meter for his electric riding mower project.

Looks like we are going in together on parts to build a set of LED meters.

[bennelson]

I had the car at the University of Wisconsin at Whitewater on Earth Day.

A student there was making a video about the event.

Here it is!

http://www.youtube.com/watch?v=yQpIwdrxQZc

[MPaulHolmes]

Ben, it's so weird seeing you on the other end of the camera! Nice video! The car's looking really good, too.

[bennelson]

This is also really the only video I have where you can hear how loud (or not) the car is.

Any of the other videos are with the camera inside the car, or you can't hear anything over the sound of gravel getting crunched!

I also like the glint of sunlight off the windshield on the still-shot representing the video!

[bennelson]

I just got a call from the battery place.

They asked me at what rate I wanted the batteries discharged at! I love these guys!

I told them that the car cruises at around 100 amps. Apparently, they have a machine that can discharge batteries at whatever rate they pick.

This will be a FAR better "real" world number than I could ever get from the info on the side of the battery. Batteries are usually listed as how many amp-hours they give at a draw of something like 20 amps.

That will be VERY different from what they give at 100 amps, especially with wierd used batteries!