Search found 56 matches

by celectric
Tue, 05 Jun 2012, 22:30
Forum: Technical and conversion discussion
Topic: Gearbox stresses
Replies: 6
Views: 1064

Gearbox stresses

As I am intending to convert a front-wheel-drive vehicle I will be keeping the gearbox/transaxle (although I may not use or keep all of the gears or the clutch to save on weight). I am concerned about the torque output of an EM vs an ICE, and whether this will put excessive stress on the gearbox. I ...
by celectric
Tue, 29 May 2012, 23:59
Forum: Batteries, charging, management and monitoring
Topic: Li-Ion "Pulse" C Rating
Replies: 15
Views: 1661

Li-Ion "Pulse" C Rating

[Hmm, I think after this I better start my own conversion thread, it's kind of gotten off topic.] OK so I could go down to 90Ah x 86 and still meet my targets - I reduced my peak power target to 70kW in line with zeva's suggestion that it will still feel like a 100kW car, but taking into account vol...
by celectric
Tue, 29 May 2012, 21:22
Forum: Batteries, charging, management and monitoring
Topic: Li-Ion "Pulse" C Rating
Replies: 15
Views: 1661

Li-Ion "Pulse" C Rating

OK so here's the plan so far, tell me if I have got this right: 86 x SE100AHA cells Nominal 300 V pack (float charge at 310 V) Max continuous current 200 A (=2C) -> 60 kW continuous -> power-to-weight = 37 W/kg for 1600kg GVM (target: 35 W/kg) Peak current 368 A (Tritium WS200 controller limit, < 4C...
by celectric
Tue, 29 May 2012, 20:33
Forum: Batteries, charging, management and monitoring
Topic: Li-Ion "Pulse" C Rating
Replies: 15
Views: 1661

Li-Ion "Pulse" C Rating

Car is tare=1100kg and gvm=1600kg which gives me only about 300kg to play with for batteries with 2 pax (would like 4 but I don't think it's going to be possible). If I'm trying to estimate the performance of my conversion, is it as simple as comparing (pack volts * current limit) to the ICE kW rati...
by celectric
Tue, 29 May 2012, 19:53
Forum: Batteries, charging, management and monitoring
Topic: Li-Ion "Pulse" C Rating
Replies: 15
Views: 1661

Li-Ion "Pulse" C Rating

Thanks guys for the info. So if I have 60Ah, 3C cells the most I can safely draw is 90A? When I'm calculating the maximum power my pack is capable of delivering, can I calculate based on (nominal pack voltage * max continuous current)? If true, 90A won't get me anywhere near the 35W/kg I saw recomme...
by celectric
Tue, 29 May 2012, 18:14
Forum: Batteries, charging, management and monitoring
Topic: Li-Ion "Pulse" C Rating
Replies: 15
Views: 1661

Li-Ion "Pulse" C Rating

The LiFePO4 cells that EV Works sells are rated to 3 or 4 C continuous and 10 or 12 C "pulse". How long is this pulse allowed to be? Can I use it for calculating the peak power output of my battery pack over say 10 seconds of acceleration or is it much shorter than that?