Replacement Battery for AT&T E2803 Cordless Phone - 700mAh / 3.6V Ni-MH Rechargeable Pack. Ensure your cordless phone has lasting power with this high-quality battery, compatible with the AT&T E2803 and similar models. Technical details: 700mAh capacity, 3.6V output, and Ni-MH chemistry (Dimensions: 45.90 x 31.20 x 10.70mm).