DALY BMS guides diagnosis of SOC differences in parallel LiFePO4 batteries
DALY BMS has released guidance for identifying differing State of Charge (SOC) in parallel LiFePO4 battery packs. The advice emphasizes that an SOC difference does not automatically indicate a fault.
Chinese battery management system (BMS) manufacturer DALY BMS has published technical guidance addressing differing State of Charge (SOC) readings in parallel-connected Lithium Iron Phosphate (LiFePO4) battery packs. The company states that differing SOC values across multiple parallel batteries do not automatically signal a hardware fault and require further diagnostics.
DALY BMS recommends users compare batteries under similar operating conditions rather than immediately attempting to equalize displayed SOC values. The assessment should include SOC, pack voltage, current, and the BMS status. It is crucial to determine if the discrepancy is solely in the reported SOC or if the batteries exhibit other operational differences, such as varying voltage or current readings.
The guidance details situations requiring deeper investigation. If SOC differences are recurring and accompanied by voltage or current anomalies, DALY BMS advises a closer examination of the battery's condition, electrical connections, and BMS data. If one battery repeatedly reaches protection limits or stops charging/discharging prematurely, it is considered stronger evidence of a potential battery-level or system integration issue.
The manufacturer reminds users that pack voltage alone should not be used as an SOC indicator but should be considered alongside other data. Similarly, cell-level imbalance within a single pack is distinct from pack-to-pack SOC differences. DALY BMS's newer 4th generation systems allow for individual monitoring of data from up to 16 parallel batteries, including voltage, current, and BMS status.
In case of issues, DALY BMS requests detailed information on battery configuration, BMS model, synchronized pack data, and inverter specifications to facilitate diagnosis. The company offers technical support and diagnostic reviews for its customers.