Rolls R-Series drop-in LFP batteries include a built-in battery management system (BMS) which offers protection in conditions where the battery voltage, current or operating/cell temperature may be unsafe or damaging for the internal cells. The switch architecture of the BMS allows charge and discharge to be stopped independently. Under these undesirable operating conditions, the internal BMS can independently interrupt charge or discharge, or disconnect it fully, as required.
| BATTERY LIMIT | PROTECTION | RESET METHOD | COMMENTS |
Cell/Pack Overvoltage | Charge Interruption | Automatic reset after time delay or discharge | If occurring more than 3 times in 2 minutes, discharge is required |
Cell/Pack Undervoltage | Discharge Interruption | Automatic reset after time delay or charge | If occurring more than 3 times in 2 minutes, charge is required |
Extended Pack Undervoltage (Stored While Empty) | Battery Cannot be Recovered | Always charge R-Series Batteries within 72 hours of full discharge | - |
Pack Overcurrent or Short Circuit | Charge and Discharge Interruption | Automatically reset after time delay | If occurring more than 3 times in 2 minutes, charge is required |
High temperature at BMS or Cell* | Charge and Discharge Interruption | Automatically reset after cooling | BMS will display alarm when approaching disconnect |
Low temperature at BMS or Cell* | Charge Interruption | Automatically reset after | BMS will display alarm when approaching disconnect |
Extreme low temperature at BMS or Cell | Charge and Discharge Interruption | Automatically reset after warming | BMS will display alarm when approaching disconnect |
(S-Series only) Secondary Overcurrent Protection | Charge and Discharge Interrupted, external fuse is blown. | Replace fuse | Secondary protection is also recommended for all R-Series batteries. |
*Temperatures outside of the ideal operating range require a reduction in charge/discharge current for optimal battery life.
The BMS also has cell-balancing functionality to balance each internal cell to the same state-of-charge, enabling the full pack capacity. However, this is not sufficient to balance severely imbalanced cells with a substantial state-of-charge (SOC) difference.