There are four major considerations for airsoft batteries before making a decision: Size, material, mAh, and voltage. Some batteries are larger and other batteries are smaller and are made to fit airsoft guns of proportional size. Before buying any airsoft battery, make sure it will fit within the battery compartment on your airsoft gun. Airsoft batteries generally fall into three different categories LiPo (Lithium Polymer), NiMH (Nickel Metal Hydride), and NiCd (Nickel Cadmium). LiPo and NiMH are very good batteries that require little maintenance. However, if you purchase a NiCd battery, beware that you may need to discharge it before storage. 

The last two considerations, Miliamp hours (mAh) and voltage go together and refer to different parts of the battery’s power supply. MAh refers to the overall capacity of the battery to hold a charge. Just like a 10-gallon tank holds more fuel than an 8-gallon tank, a 1600-mAh battery holds more charge than a 1200-mAh battery. 

This translates into more play time between charging cycles. The voltage, however, refers to the actual power output of the battery–an important consideration for your airsoft gun’s gearbox. The owner’s manual that came with your airsoft gun should be able to guide upper and lower voltage limits for your airsoft gun. Going too high can break the gearbox and going too low will fail to provide enough power to shoot the BBs any meaningful distance.

Airsoft battery chargers are less complicated than airsoft batteries but still have nuances that players must be aware of. First, not every airsoft charger will work for every batter. Before you buy a charger make sure that it corresponds to the kind of battery that you have. Chargers usually come in two categories: NiCd and NiMH chargers, and LiPo balance chargers. 

Given the nature of lithium polymer batteries, different cells within the batteries can carry different levels of charge. LiPo balance chargers help create an equilibrium between the individual cells on the LiPo batteries. Please note that NiCd/NiMh and LiPo chargers are generally not cross-compatible. Using the wrong charger with the wrong battery can damage both the charger and the battery.

We also recommend that players look for smart chargers for their airsoft batteries. Smart chargers have sensors that prevent undercharging and overcharging the battery and help extend the overall life of the battery.