Panasonic Original Ni-MH Rechargeable Batteries (2 Packs of 2) for the KX-TGA651 - KX-TG6511B - KX-TG6512B & KX-TG6513B DECT 6.0 PLUS Expandable Cordless Phone System Black Battery works over 6 hours of talk time on one charge. (can work much longer, depending on the phone.) Dont get cut off in the middle of a phone call, have your phone recharged all the time. Enjoy exceptional battery performance and minimal charging time. Recharges Faster and Lasts Longer Than Imitation Batteries Dont Damage Your Cordless Phone by Using Off-Brand Imitation Batteries - Stay Safe and Use Panasonic Original Batteries Only