Quick Answer
Most RC planes use 2S to 4S LiPo batteries with capacities between 1000mAh and 5000mAh. The right battery depends on your aircraft size, motor Kv rating, and how long you want to fly. Match the cell count to your motor and ESC, then pick the highest capacity that fits within your plane's weight budget.
Understanding RC Plane Battery Basics
RC aircraft run almost exclusively on LiPo (Lithium Polymer) batteries. They offer high discharge rates in a lightweight package, which is exactly what a flying model needs. A typical RC plane battery is rated by three numbers: cell count (2S, 3S, 4S), capacity in milliamp-hours (mAh), and C-rating (discharge rate).
Cell count determines voltage. A 2S pack delivers 7.4V nominal, 3S gives 11.1V, and 4S provides 14.8V. Higher voltage means more power to the motor, but your ESC and motor must be rated for it. Check your motor's specs before going up in cell count.
Capacity affects flight time. A 1500mAh pack can theoretically deliver 1500mA for one hour. In practice, a medium-size RC plane drawing 15-20A will get roughly 5-8 minutes from a 1500mAh 3S pack. Doubling capacity roughly doubles flight time, but also adds weight.
Which Cell Count for Which Plane?
Small park flyers and micro planes (under 500mm wingspan) typically use 2S packs. These are lightweight and deliver enough voltage for small brushless motors. A 3S pack like this 1550mAh DOGCOM is the sweet spot for most mid-size trainers and sport planes around 800-1200mm wingspan.
4S batteries suit larger, faster models and many FPV wing builds. A 4S 1500mAh like the CNHL Black Series gives you the extra voltage for aggressive climbs and faster passes, making it a strong choice for warbirds, FPV wings, and aerobatic models.
For detailed comparisons between 4S and higher cell counts, our 4S vs 6S battery guide breaks down the tradeoffs.
Capacity, Weight, and Flight Time
Bigger is not always better. Adding a larger battery increases wing loading and changes the centre of gravity, both of which affect how the plane handles. As a rough guide, your battery should be 15-25% of the model's total weight.
A 1000-1300mAh pack works well for small 2-3S park flyers. For larger sport planes and trainers, 1500-2200mAh in 3S or 4S is common. If you are building a long-endurance FPV platform, 3000-5000mAh may be appropriate, but watch the weight.
The C-rating tells you the maximum safe discharge current. A 1500mAh 50C battery can deliver 75A (1.5Ah x 50). For most RC planes, 30-50C is plenty. High-performance models may need 70C or more. Our article on battery safety and C-ratings explains this in detail.
Connectors and Compatibility
The two most common battery connectors in RC planes are XT30 and XT60. XT30 suits smaller packs (under 1000mAh, 2-3S) while XT60 handles the higher currents of larger 3-6S packs. Make sure your battery connector matches your ESC or use a quality adapter.
Balance leads are essential. Every 2S+ LiPo pack has a balance connector that allows the charger to monitor and adjust individual cell voltages. Never charge a LiPo without balance charging.
A good charger makes a real difference. The ISDT K4 600W dual charger can handle 1-6S packs and charge two at once, which is ideal if you run multiple planes. Browse our full range of battery chargers for more options.
LiPo vs Li-Ion for RC Planes
LiPo batteries are the standard choice for RC planes because they deliver high burst current and weigh less per cell. Li-Ion cells (typically 18650 or 21700) offer higher energy density and more cycles, but their lower discharge rate makes them better suited to low-draw long-endurance setups.
For most pilots, LiPo is the right answer. If you are building a long-range FPV plane and want maximum flight time per gram, Li-Ion might be worth considering. Our Li-Ion vs LiPo comparison covers the details.
FAQ
Q: Can I use a drone battery in my RC plane?
A: Yes, as long as the cell count, capacity, and discharge rating match your plane's requirements. The batteries sold for FPV drones work perfectly in RC planes. Check that the physical dimensions fit your battery bay.
Q: What voltage should I store my RC plane batteries at?
A: Store LiPo packs at 3.80V per cell (storage voltage). Never store fully charged or depleted packs. See our LiPo charging guide for the full charging and storage routine.
Q: How do I know what battery fits my RC plane?
A: Check the manufacturer's recommended battery range (cell count and capacity). If building from scratch, match the battery voltage to your motor Kv and ESC rating, then choose the largest capacity that stays within 15-25% of total model weight.