if the cells are all at the same voltage 2,5 or above it may just be as simole as connecting bms to the cells. let me wake up. there should be 4 groups of cells in each 12v battery. I would go with a smart bms Ant or JBD 12S minimum Ant Bms's usually cover a range 10-20s, 8-24s etc.
The cells are probably all ready in 4 groups of cells in each battery, if possible check each individual cell capacity. Not just voltage. Charge up each 4s to 14.6 after sitting for a few hours you may find the voltage most likely be around 13.36v-13.8v, 3.34v-3.45v per cell this is normal. Connect all three 4s together in parallel charge to 14.6v. Let sit untouched except for voltage checks for at least two days check voltages of individual cell groups and 4s sections. connect each 4ssection in series with the next section. Add The Bms following the instructions included with the BMS.
Charge your new 12s battery to 40.8v-42v. 90% of the LiFePO4 battery Capacity is between 40.8v-36v. (3.4v-3v) Your resting voltage of your battery may be higher than my 12s LiFePO4 battery.
later floyd
ps check my Calculations as I haven't had my first cup of coffee yet.
The cells are probably all ready in 4 groups of cells in each battery, if possible check each individual cell capacity. Not just voltage. Charge up each 4s to 14.6 after sitting for a few hours you may find the voltage most likely be around 13.36v-13.8v, 3.34v-3.45v per cell this is normal. Connect all three 4s together in parallel charge to 14.6v. Let sit untouched except for voltage checks for at least two days check voltages of individual cell groups and 4s sections. connect each 4ssection in series with the next section. Add The Bms following the instructions included with the BMS.
Charge your new 12s battery to 40.8v-42v. 90% of the LiFePO4 battery Capacity is between 40.8v-36v. (3.4v-3v) Your resting voltage of your battery may be higher than my 12s LiFePO4 battery.
later floyd
ps check my Calculations as I haven't had my first cup of coffee yet.