Lately I've been doing research and testing on the nights I go to Synkromotive, so not much has happened with the bike, but we have got new batteries.

As I posted before, I found a guy locally that had a ton (almost literally) of 28Ah 12V batteries from panasonic. I bought 2 (to replace in a go-kart we had at the shop), and tested one of them. I ran 2 tests. One test was at 50A another was 100A. It performed well and passed load testing. After looking at the Logged data, we figured the values jumped around too much, so I hooked a Dataq data logger to the battery and logged voltage vs time at 50A. Here's the curve.

After testing the one battery, Ives and I ran some power calcs, and at 100A with a 120V (115V under sag) it'd give me over 11,500W instantanious, lots more than what I was getting (60V sag and just under 150A, for about 9,000W. It matched the discharge curve from the battery datasheet. We're going to install 7 of these batteries (84V) on Tuesday night for a quick test. These will fit in with little or no modification to the existing frame (we designed it to be compatible with this size of batteries for an upgrade when we fabricated it in March). Once we do a quick test or two, we can start to fabricate another battery tray.

I also played around with an optical sensor that I've got hooked into the Tach input on the controller. I tried to get it to calibrate, but its not logging correctly. I'll have to debug that later.

For a gauge display, I'm tossing ideas around and considering an Asus EEE 7inch with XP on it. Fairly low cost, and it'd do all my data logging, display, etc. Plus, it will run our software with no changes. Just hook up a USB cable, and voila. Just need to make a waterproof case for it, and some sort of one-button interface for toggling pages. Once my BMS is done (needs programming) we can display all the battery levels, log data for discharging and charging, and display all the controller stats.

Still need to get some time off work to go to the DMV to get it registered and to take the written test for my motorcycle endorsement so I can get a permit. The permit allows me to ride with someone within eyesight and only drive during daylight hours. Then I can get some seat time.