Because of it's small battery compartment, when compared to the KWA crane stock or handguards, which can house bigger batteries, you may find it easier to source a 7.4V (2S) Li-Po battery that will fit into your AKR's battery compartment, although there are some 3s, 11.1V battery configuarations that will fit. A Li-Po battery helps the user achieve better trigger response and a faster rate of fire than standard Ni-Mh batteries can offer. The diagram will show the maximum space the battery can take up on the KWA AKR. The battery is installed into the upper handguard. Regardless of size, we do not recommend using a battery with a higher discharge (C- rating) than 20c, or an MAH rating that is higher than 1600, as this can negatively affect cycling and feeding in an AEG.