What are the main types of batteries for RC use?

Several types of batteries are used within RC applications, but the most common are NiMH (nickel-metal hydride) and LiPo (lithium polymer). There are also older NiCd batteries and the more modern Li-Ion variants, but these are less commonly used in RC airplanes, RC helicopters or cars.

NiMH batteries are relatively safe, inexpensive and easy to use. However, they have a lower energy density, which means they are heavier and offer less capacity for the same size. Therefore, they are still mostly used in transmitters or in beginner models.

LiPo batteries are the standard for propulsion today. They are light, powerful and can deliver high currents, which is perfect for motors that demand a lot of power. Their disadvantage is that they are more sensitive: overcharging or discharging too deeply can be dangerous and lead to fire or explosion.

Li-ion batteries are sometimes used as an alternative to LiPos, especially when energy density is more important than peak power. They have a longer life but deliver lower currents.

In short: for transmitters and simple applications, NiMH is often sufficient, but for propulsion in RC aircraft and helicopters, LiPos are the best choice because of their power and low weight.