A single Epoch AA Rechargeable Battery will replace 1000+ standard alkaline batteries. Consider all of the wasted resources and harm to environment in producing, packaging and disposing of alkaline batteries. Charges at a rate 5X a Ni-MH Rechargeable AA Battery. Complete charge completed in less than 2 hours. Compatible with all devices that use standard AA batteries with a constant 1.5V discharge. Built in LED will let you know when your batteries are recharged and ready to go. RED = Charging, BLUE = Fully Charged Please Note: These batteries can only be charged with the supplied or any other micro usb cable Included: (4) Epoch AA USB Rechargeable Batteries (1) 4x AA Plastic Carrying Case (1) USB 4x Quick Charging Cable SPECIFICATIONS: MPN: NCR3450AA Size: AA Style: Button Top Chemistry: Li-ion Rated Capacity: 2300mAh (3450mWh) Max Continuous Discharge Rating: 1.5A Voltage: 1.5V (Constant during discharge) Rechargeable: Yes, via USB Quick Charging Cable (Included) - 2 Hour Full Charge (up to 1000 recharge cycles) Protected: Yes, Protection Circuit built into the Anode Approximate Dimensions: 14.75mm x 50.20mm Weight: Max 35g