FOXPRO recommends the use of the rechargeable batteries to power your digital game call for optimum performance. These callers all feature dual speakers and dual amplification that will run through regular alkaline batteries much faster than other units. To save money on alkaline batteries, use the NiMH batteries and charger! This kit includes 8 AA NiMH (nickel-metal-hydride) batteries and a standard wall charger for use in your home. This kit will charge completely depleted batteries in about 10 hours.