8x 1.2v 1600 mAh NiMH cells arranged in strait-line formation to make the AK stick type 9.6v battery. This battery has also been known to fit in Galils with some minor modification to the AEG.
NiMH (Nickel Metal Hydride) cells charge and discharge a little bit faster than NiCAD (Nickel Cadmium) cells but still slower than LiPo (Lithium-Ion Polymer) cells. NiMH where the *hot* batteries back in the day before LiPos where available.
Though many have switched to LiPos these days there is still a die-hard following of users who are not yet convinced of the LiPos safety and so choose to stay with NiCADs and NiMHs.