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Do you need BMS for lithium ion batteries in parallel?

I have a device that runs on lithium-ion batteries. The device already has a charging circuit. The maximum load capacity is 300 mA, and the maximum charging current reaches 500 mA. To sum up, if there are 3 batteries in parallel (1 s3p), do I need to install a BMS or any additional protection circuit?

Battery Management System
September 28, 2023

Yes, installing BMS for lithium ion batteries is needed to protect your parallel circuit.
1. At a minimum, a combination of discharge cutoff and discharge current limitation shall be required.
2. Set the current limit by the BMS to slightly above your maximum 300 mA load, rather than the battery rating of a typical protection circuit.
3. In addition, when the battery is abnormal, BMS can help disconnect the circuit to protect equipment safety.

MORE: How many BMS should be installed for two separate lithium-ion battery packs connected in series?

Jessica Liu

Jessica Liu is an engineer at MOKOEnergy with expertise in IoT devices, MCU, VCU, inverter, and BMS. She has a degree in automation, 6 years of work experience, and several certifications in project management.

Jessica Liu

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