Seth wrote: > > .. > That being said, regen set to the same power level as traction can be > violent if they aren't easily and finely controlled.
They are in my case. We've been through this before. And the batteries > need to be able to charge at the same rate as discharge, which may be > difficult with a high voltage pack if you want to respect battery and > controller voltage limits. This one is real: if your pack is approaching top inverter voltage limit, regen is reduced. Either put up with it for a few first electric miles, or size your pack so you stay away from this limit. For example, 70kW (peak) into a 336V pack (28 > modules) at less than 420V (15 volts per module and a high voltage for a > controller with 600V IGBTs) is 167A DC. I know, that's why I had 27 batteries once. And Optimas love occasional inrush of 100A-200A for few seconds. Other chemistries may not be so tolerant. Sometimes the kinetic energy is > absorbed before the voltage roof is hit, sometimes it isn't. Battery > chemistry, temperature, Ah capacity and SOC all are factors. Which is > another argument for regen being supplementary, not the primary retarder. I will never substitute mechanical brakes for regen. Mechanical is still primary by importance in emergency situations, but hands down secondary in everyday practical usage frequency. Of course I can stop ACRX without regen, but not as easily as stock ICE. But *still* good enough not to mess with upgrades, especially with nice vac assist. Victor
