This 2 x 1.5V AA Battery Holder can hold 2  1.5VAA battery which can make  3.0 V rechargeable battery pack from NiMH / NiCd cells or 9V battery pack from alkaline cells or it can also be used for one-time use and throw batteries for small DIY projects. The battery holder puts the batteries in series so that you have 2x the voltage of an AA battery. (approx. 3.0V)