View Single Post
Old 07-20-2010, 02:38 PM   #32 (permalink)
Electric Porsche
ExplodingDinosaurs's Avatar
Join Date: Jun 2009
Location: Earth
Posts: 29
Thanks: 7
Thanked 3 Times in 3 Posts
Here's a post I made to the blog:

Jack, thanks for the testing and publishing your results.

How long had the car sat before the test? If the car sat for a few days, I could see the oil being stiffer and the batteries less responsive for the regen test. Then the batteries would be a bit stronger for the non-regen test the next day since they have been recently exercised.

Ideally you'd do "ABABAB..." type testing -- regen one day, nonregen the next, multiple times. This would accomplish 2 things: One is to look for system drifts, like batteries working better due to recent use. The other is to give you some statistics -- if the numbers are jumping around you might not have a statistically significant difference (or sameness).

I have a car with regen, I'll have to try your test myself. One thing I have noticed: If I do strong regens (like occasional 200+ Amps), my lead acid batteries stay very well balanced with no BMS (all within about 0.03 Volts). With weak regens (50 Amps), the batteries quickly drift to be 0.5+ Volts apart. Jack have you seen anything like that with your cars and lithiums?
  Reply With Quote