Batteries are the power source of your FPV drone—without them, no copter ever gets off the ground. In the FPV world, two main battery types are used: Lithium Polymer (LiPo) and Lithium-Ion (Li-Ion) batteries. Both have different strengths and use cases, but they share one important thing: they require careful and safe handling.
In this chapter, you’ll learn the most important differences, key terms, and—most importantly—safety rules when dealing with these batteries.
| Feature | LiPo | Li-Ion |
|---|---|---|
| Form factor | Flat, soft (usually shrink-wrapped) | Cylindrical (similar to AA cells) |
| Energy density | Lower | Higher (longer possible flight time) |
| Discharge capability (C-rate) | Very high (ideal for high current) | Lower (better for steady loads) |
| Typical use | Racing and freestyle drones | Long-range setups |
| Sensitivity | Higher (especially during charging) | Slightly more robust |
Batteries are usually labeled with a combination of numbers and letters—these provide essential information.
This indicates the number of cells connected in series. Each cell has a nominal voltage of about 3.7 V.
A 4S battery therefore has 4 cells in series → 14.8 V (4 × 3.7 V).
More cells mean higher voltage, which results in more power—but also more stress on electronic components.
Capacity describes how much energy the battery can store.
1500 mAh = 1.5 Ah → at an average current draw of around 30 A, this results in roughly 3 minutes of flight time.
Higher capacity means longer flight time, but also more weight.
The C-rate indicates how much current the battery can deliver.