How to Choose the Right Lithium Battery for Your Device

1. Determine the voltage platform

The voltage platform is set by the rated voltage of the equipment. LiFePO4 cells are 3.2V nominal (3.65V full charge) while NCM / LCO cells are 3.7V nominal (4.2V full charge); chargers are not interchangeable. E-bikes commonly use 36V / 48V / 60V / 72V platforms, while professional drones use 22.2V (6S) to 88.8V (24S).

2. Then look at capacity and energy

Capacity (Ah) multiplied by voltage gives energy (Wh), and energy determines runtime. Once the voltage is fixed, estimate the required Wh from the target runtime and convert it into capacity.

3. Match the discharge rate

Continuous discharge current should match the working current with a margin. Standard energy cells are 1–3C, power cells 3–10C, and high-rate UAV cells can reach 10–30C.

4. Check dimensions and weight

Battery compartment size and overall weight budget are hard constraints. Higher energy density means less weight for the same capacity; 21700 cylindrical cells help increase capacity within a limited space.

5. Cycle life and BMS

Cycle life affects cost of ownership and the BMS determines safety. Choose a smart BMS with over-charge, over-discharge, over-current, short-circuit and temperature protection, rated for the continuous current required.

6. Certifications and compliance

Export shipments generally require UN38.3 and MSDS; some markets also require IEC62133, CB, KC or UL. Confirm the certification scope at the selection stage to avoid rework later.

Note: the above is a general selection approach; specific parameters are subject to the manufacturer datasheet and sample test results.