These are the settings for my 12.8V 628Ah Battery. If you are using another battery, you need to edit the cell count and capacity in the first two settings.
Cell Count4
The number of cells in series that the BMS monitors. Count the series groups, not the total number of physical cells, so a 2P4S battery is still entered as 4. A 12V battery uses 4, a 24V battery 8 and a 48V battery 16.
Capacity628 Ah
The total capacity of the battery as the BMS sees it, not the capacity of one physical cell. Cells wired in parallel count as a single cell, so two 314 Ah cells in parallel are entered as 628 Ah. The BMS uses this number to calculate the state of charge.
Bal. Delta Volt0.03 V
The voltage difference between the highest and the lowest cell that has to be exceeded before the balancer switches on. As long as the difference stays below this value, the BMS leaves the cells alone.
Bal. Start Volt3.45 V
The balancer only runs once the highest cell climbs above this voltage. Both conditions have to be true at the same time: the highest cell above this voltage and the difference between cells above Bal. Delta Volt.
Max. Bal. Current2 A
The highest current the balancer is allowed to move between cells. Set it to the maximum your BMS supports, because a higher balance current only shortens the time needed to even the cells out.
Cell OVP3.65 V
If any single cell reaches this voltage, the BMS switches off charging to protect that cell. Treat it as a last resort, not as a charge target.
Cell RCV3.56 V
The charge voltage the BMS asks the inverter or charger to deliver, sent over the communication cable. It only does something when the inverter is actually talking to the BMS over CAN or RS485.
SOC-100%3.55 V
The cell voltage at which the BMS resets its state of charge reading to 100%. The gauge only reaches 100% if you genuinely charge the cells this high.
Cell OVPR3.45 V
After a high voltage cutoff, the cell has to drop back below this voltage before the BMS allows charging again.
Cell UVPR2.65 V
After a low voltage cutoff, the cell has to rise back above this voltage before the BMS allows discharging again.
SOC-0%2.64 V
The cell voltage at which the BMS resets its state of charge reading to 0%.
Cell UVP2.60 V
If any single cell drops to this voltage, the BMS switches off discharging to protect that cell.
PwrOff Volt2.50 V
If a cell keeps falling to this voltage, the BMS shuts itself down so that its own idle consumption does not drain the cells any further.
Continued ChgCurr240 A
The highest charge current the BMS allows continuously. I’ve set it to 240A because my battery has a built in 300A fuse.
Chg OCP Delay5 s
How long the charge current is allowed to stay above the limit before the BMS trips. Short spikes are ignored, anything that lasts longer than this shuts charging off.
Chg OCPR Time60 s
After a charge overcurrent trip, how long the BMS waits before it switches charging back on.
Continued DsgCurr240 A
The highest discharge current the BMS allows continuously. I’ve set it to 240A because my battery has a built in 300A fuse.
Dsg OCP Delay10 s
How long the discharge current is allowed to stay above the limit before the BMS trips. This is usually set a little longer than the charge delay so that motor and inverter startup surges do not trip the battery.
Dsg OCPR Time60 s
After a discharge overcurrent trip, how long the BMS waits before it switches discharging back on.
Charge OTP60 °C
If the cell temperature reaches this value, the BMS stops charging.
Charge OTPR55 °C
After a high temperature cutoff, the cells have to cool back down to this temperature before charging is allowed again.
Charge UTPR5 °C
After a low temperature cutoff, the cells have to warm back up to this temperature before charging is allowed again.
Charge UTP0 °C
If the cell temperature drops to this value, the BMS stops charging. Charging LiFePO4 below freezing plates metallic lithium on the anode and permanently damages the cell.
Discharge OTP60 °C
If the cell temperature reaches this value, the BMS stops discharging.
Discharge OTPR55 °C
After a high temperature cutoff, the cells have to cool back down to this temperature before discharging is allowed again.
CMOS OTP80 °C
The temperature of the MOSFETs inside the BMS itself, not of the cells. At this value the BMS switches both charging and discharging off to protect its own electronics.
CMOS OTPR70 °C
The MOSFETs have to cool back down to this temperature before the BMS allows charging and discharging again.