Wasabi Power Battery Pack for Flip ABT1W and Flip UltraHD 4GB Video Camera Rechargeable NiMH Battery Pack compatible with Flip Ultra (2nd generation) and Flip UltraHD (4GB/1hr) Camcorders (U260 models, U2120 models, U1120 models) Provides 4.5 hours of battery life for your Flip Ultra (2nd Generation) or 2.5 hours for your Flip UltraHD (4GB/1hr) Camcorder Recharges when connected to USB or to Flip Video Power Adapter; cannot be charged outside of camcorder Ni-MH battery rated at 2.4V and 2400mah Includes battery with 3-year manufacturer warranty