DALY BMS Issues Guide on Current Rating for 48V LiFePO4 Battery Packs

DALY BMS, a manufacturer of battery management systems (BMS), has published a technical guide to help users select the appropriate current rating for 48V LiFePO4 battery packs. The guide highlights that choosing a BMS is not a simple matter of matching an inverter's power rating to the BMS's amperage.

According to the company, battery pack manufacturers and home energy storage integrators must understand the actual continuous discharge current, charging current, and short-duration peak loads before selecting a BMS rating. DALY BMS's 4th generation LK series offers a 100A continuous current rating, while the LM series provides 150A and 200A options. However, these ratings do not directly correspond to specific inverter power ratings.

The guide advises confirming the battery configuration and operating voltage, as a lower battery voltage requires higher current to deliver the same power output. While illustrative examples show a 3,000W inverter potentially drawing around 65A at 51.2V, DALY stresses that the selected BMS's continuous discharge and charge rating must comfortably exceed the actual operating current with a margin for temperature and aging.

Furthermore, the guide urges users to check charging current and peak loads, ensure cell and pack capability, and verify the inverter's specific battery-side input current specifications. DALY BMS also emphasizes that protocol compatibility is not guaranteed by the mere presence of a CAN or RS485 connector, requiring a compatibility check.

DALY BMS offers higher current rating options for continuous requirements exceeding 200A and recommends contacting their engineering team for model recommendations. The company reminds users that system wiring must follow model-specific documentation and general tutorials should not be used as a substitute.