iconoclast
1 mW
I need to replace the six 12v batteries (6S, 72v) in a GEM NEV.
Almost all of the drop-in 12v LFP suppliers recommend not connecting more than 4 in series. I understand about balancing to .2v before connecting, and charging each of these 12v batteries independently because the BMW will cut off power to the whole string when the first battery reaches full charge.
What components in the BMS limit use in a configuration to 48v? Just the MOSFETs?
I saw a comment in one thread that mentioned that the MOS components of the BMS have a voltage withstand value of 80v. What kind of headroom is needed? Does anyone have experience upgrading these 12v BMS to support 6S / 72v or higher voltages?
If a diode was used on the interconnects to eliminate battery backflow, would that be sufficient protection? (I can easily charge the batteries individually).
I can solder and like to upgrade controllers, have limited experience with BMS.
(Ogrphy is selling a 12v 100ah LiFEPO4 battery on Amazon for $340. Chin and others have similar batteries for $380. That's very competitive with FLA batteries, but of course 2x usable capacity, 10x cycle life, 1/3 weight. If these batteries can be made to work it would be a big win for the NEV community)
Almost all of the drop-in 12v LFP suppliers recommend not connecting more than 4 in series. I understand about balancing to .2v before connecting, and charging each of these 12v batteries independently because the BMW will cut off power to the whole string when the first battery reaches full charge.
What components in the BMS limit use in a configuration to 48v? Just the MOSFETs?
I saw a comment in one thread that mentioned that the MOS components of the BMS have a voltage withstand value of 80v. What kind of headroom is needed? Does anyone have experience upgrading these 12v BMS to support 6S / 72v or higher voltages?
If a diode was used on the interconnects to eliminate battery backflow, would that be sufficient protection? (I can easily charge the batteries individually).
I can solder and like to upgrade controllers, have limited experience with BMS.
(Ogrphy is selling a 12v 100ah LiFEPO4 battery on Amazon for $340. Chin and others have similar batteries for $380. That's very competitive with FLA batteries, but of course 2x usable capacity, 10x cycle life, 1/3 weight. If these batteries can be made to work it would be a big win for the NEV community)