John Frum
Tell me your problems
- Joined
- Nov 30, 2019
- Messages
- 15,233
Well, I was assuming the BMS on the battery (provided by BigBattery), which is supposed to disconnect at 20V, would suffice.
You will almost certainly disconnect when your weakest cell hits 2.5 volts before the pack hits 20 volts.
Also discharging until one cell is dead empty will tend to destroy your top balance.
Finally and most important...
If the bms is fet based, disconnecting under significant load will be very hard on the bms.
Fet based BMSs can fail closed which means you won't know its not working until your cells get destroyed.
If the bms uses a contactor its not so bad but still pretty hard on the contactor.
Anyway the bms is generally considered to be your reserve parachute.