EM-CPB-486B - Ni-CD, 3.6 Volt, 900 mAh, Ultra Hi-Capacity Battery - Replacement Battery for Sony BP-T38 Cordless Phone Battery Replacement Battery for Sony BP-T38 - Ni-CD, 3.6 Volt, 900 mAh. 100% compatible with your OEM battery - 3 year warranty. Made with high quality Japanese cells. Synergy Digital is a Registered Trademark