I've been driving BMW i3 for couple years and recently traded it for Tesla Model S. Right away I noticed difference in regenerative braking behavior. First Tesla doesn't stop completely like BMW but starts coasting at around 5mph - forces to use friction brakes which wasn't necessary in BMW. Second and more annoying one is non-linear deceleration (it makes it very hard to predict where car will stop and forces me to depress accelerator closer to the end of braking). My butt-dyno was screaming - something fishy is going on at the end off deceleration right before regen gives up at around 10mph. My assumption was that it is software glitch in regen rate limiter and I decided to check exact metrics. It showed that my assumption was incorrect (regen current to battery pack was linear) but butt-dyno didn't lie. So what is the heck going on there?
Need help from gurus and have complete CAN3 log for the measuring period. I highlighted 4 specific periods: 1 - linear deceleration, current (what one may expect); 2 - deceleration kicks-in while regen current stays constant; 3 - regen gives up and car starts coasting at around 5mph; 4 - I hit friction brakes.
What is happening on in period #2? If regen doesn't increase what makes car brake 2 times more heavily?
Legend: Green line is calculated and scaled deceleration rate to fit on the screen, it lags a little since it is 1 second moving average; Yellow - pack current in Amperes; Blue - speed in mph;
Need help from gurus and have complete CAN3 log for the measuring period. I highlighted 4 specific periods: 1 - linear deceleration, current (what one may expect); 2 - deceleration kicks-in while regen current stays constant; 3 - regen gives up and car starts coasting at around 5mph; 4 - I hit friction brakes.
What is happening on in period #2? If regen doesn't increase what makes car brake 2 times more heavily?
Legend: Green line is calculated and scaled deceleration rate to fit on the screen, it lags a little since it is 1 second moving average; Yellow - pack current in Amperes; Blue - speed in mph;
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