I've seen my display show spikes of just over 130kW when I have full HVAC with defrost going, full throttle. It definitely ramps down the peak power allowed on a short countdown, but since I can't drive straight up a wall for a mile, I don't know if its a 10s ramp or longer, I hit top speed at around that time.Oberon wrote:Given that the 105kW / 369 volts is 285 A, with a 60 Ah pack that would be 4.75 C. I doubt that the 105kW is intended to be only a 30s rating, so it seems likely these are not the 5C cells.Skullbearer wrote:We have to be careful with speculation on the A123 cells, they don't publish all their options and have both 'energy' and 'power' cells. The cells that are commonly in this form factor pack are 'energy' cells and have a spec 10s peak discharge rate of only 10C, and a 30s of 5C.
To my knowledge there is no A123 pouch cell that is more of an 'energy' cell than the 5C/10C units. HOWEVER when I was trying to use them for Formula Hybrid in college, the 5C/10C rating was what they provided on internal documents to distributors... their official 'recommended' usage was only 3C/6C, which more closely matches what we actually see on our Sparks.
130kW / 350V is ~372A, or 6.2C
The cells should definitely be fine for up to 10C in <10s bursts, but repeated bursts at that WILL heat the battery up quite a bit. My speculation is that GM didn't want to do that... even with hard regen stops and hard accelerations repeated, I can't get my battery hot enough in 70F ambient to get anything on the 'Battery Conditioning' usage in my Energy tab. Most definitely not being pushed, the battery is acting as a sealed unit for me (unless my Spark is not reporting correctly).
We could convert the rear wheels to be driven. I haven't put my Spark up on the lift yet, anyone have pictures of the available space in the rear, by the battery? Hub motors are always an option.