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

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

Answer: You can use 18650 Li-ion cells in an RC plane, but there are important considerations. LiPo batteries are popular because they deliver high current with a flat discharge curve and are lightweight. In contrast, 18650 cells typically have lower maximum continuous discharge rates and are heavier. To use 18650s, first check the current draw of your motor and electronics; ensure the cells' continuous discharge rating (often 10-20A per cell) matches or exceeds this. Connect enough cells in series to match the voltage of your original LiPo pack (e.g., 3S LiPo ≈ 11.1V, so 3 cells in series). Use a quality battery management system (BMS) to protect against overcharge, over-discharge, and balance the cells. Expect a heavier battery pack, which may affect flight performance. Finally, test the setup carefully on the ground, monitoring temperature and voltage under load. If your plane demands high current bursts, LiPo batteries generally remain the better choice.