Battery chemistry is important. Before buying a battery for your electric airsoft gun (AEG) confirm battery compatibility. Some airsoft guns can use either Lithium (LiPo) or Nickel Metal Hydride (NiMH) but others can only take one of the two. This is equally important when choosing a battery charger. Use caution when charging batteries, especially LiPo batteries, as they can generate a lot of heat, or, if worn out, can cause a fire. Always charge LiPo batteries in a charging bag.