Got it, thanks. What batteries do you recommend?jkenny23 wrote: ↑Thu Nov 14, 2019 12:59 pmI really don't advise using LiFePO4 with an extender unless you expect your extender battery to be able to handle the full charging and discharging current (120A charging, 280A discharging). LiFePO4 is such a vastly different chemistry than LMO that I foresee a lot of problems trying to parallel the 2, not even getting into the different charging profile and termination characteristic.map40home wrote: ↑Thu Nov 14, 2019 12:04 pm
Thanks for the answer. I want one. If I understand correctly, I just need:
1) Batteries to produce 384V nominal (for me, 8 sets of 48V nominal LifoPo4 with their own BMS, in series)
2) Connection to the power cables out of the battery to parallel the new pack (with a nice reseteable fuse in the middle for safety)
3) Relays to connect/disconnect the extender so there is no damage to the resistor in case you turn off the car and the extender is still connected. (By the way, is it possible that you could sell us the wiring diagram for those relays?)
4) CAN in the middle attack board
Am I missing something?
Once again, thanks Mux, looking forward for you to share with us your knowledge.
What kind of resettable fuse have you found that can interrupt 400VDC at 300A? I would be interested in such a part.
I can provide the wiring diagram for the contactors, it will basically be identical to the ones already in the car main battery, sharing the same control lines also. If you're new to EVs, you need to use things called contactors which are specially designed to stop DC arcs and have a much higher rating than a typical AC relay, which can get away with less since there's a zero crossing in the waveform.
I could use the wiring diagram if you have it handy
I’ll see if I get you the part number for the resettable fuse. If I recall, it was 250 amps