Can I Replace LiPo Batteries with 18650 Li-ion Cells in My RC Plane?

Question: Can I use Li-ion 18650 cells instead of LiPo in an RC plane?

Answer: While it is possible to use 18650 Li-ion cells in an RC plane, there are important considerations. LiPo batteries are preferred because they deliver high current with a flat discharge curve, essential for motors demanding quick bursts of power. 18650 cells typically have lower continuous discharge rates, so first check if the cells can provide sufficient amps for your motor.

To use 18650 cells, you’ll need to configure them in series and parallel to match the voltage and capacity of your original LiPo pack. For example, a 3S LiPo (11.1V nominal) would require at least three 18650 cells in series. Ensure all cells are matched in capacity and health to avoid imbalance.

Use a proper Li-ion battery management system (BMS) to handle charging and protection, since Li-ion cells have different charging requirements than LiPo. Also, 18650 packs are usually heavier and larger, which might affect flight performance.

In summary: verify discharge rates, match voltage and capacity, use a suitable BMS, and expect some weight penalty. For most RC planes, LiPo remains the best choice for power-to-weight and performance.