>Insufficiently controlled regen has been a contributing factor in a couple >of EV racing accidents. Most commercial EVs, including the Solectrias, have >been set up with fairly mild braking effect for this reason.
I worked as an official at a solar car rayce in Kansas this summer. My job was to watch one of the corners on the track (2 mile road course) and radio in if there were any problems with the cars, rule violations, etc. One of the days of raycing was ideal conditions, bright sun and clear skys, the only problem was a roughly 15 mph wind (gusting to 25). Regen is a huge part of solar car racing, on the cross-country race we went whole days without touching the hydraulic brakes. Regen was also a big part of this track race since most of the corners could be done with regen alone. The sun was so good that day that the top teams (space grade arrays, Li-On betteries) we having problems draining there battery packs at all, they simply couldn't drive fast enough. So one team comes into my corner way too fast and puts there car up on two wheels (3 wheeled car), the only thing that kept the car from going over was the back left corner of their shell. As a solar car guy, that was the scariest thing I have ever seen. The rules (and common sense) force us the design the cars safe, but no one really wants to test the car in real life. I talked to the driver of the car later that day about what caused the accident. He said that coming into the corner (at about 55 mph) he hit the regen, but this time it didn't do anything. When he then hit the brakes in a panic situation the body of the car rolled forward and together the combination of the wind and the high cornering speed almost rolled the car. See, there battery protection system shut down the regen when the pack voltage was too high. Now I am not trying to say any of your cars are similar to a 560 lb solar car, but please don't rely on regen for ANY of your emergency braking. Just my 2 x 10^0 coulombs. Keith -- From: Keith Richtman Mechanical Team Leader Sunsetters - NDSU Solar Race Team <http://www.sunsetters.org> Tel: (701) 239-6935 [mailto:[EMAIL PROTECTED]]
