Amazon.com: Synergy Digital Cordless Phone Battery, Works with Siemens Gigaset A260 Cordless Phone, (Ni-MH, 2.4V, 650 mAh) Ultra High Capacity, Compatible with GP 55AAAHR28MX Battery : Electronics
Siemens C25 C25 Power C2588 C25e C28 Replacement Battery: BatteryClerk.com Mobile Phone
Cameron Sino 700mAh Battery V30145-k1310-X103 for Siemens C25, C25 Power, C2588, C25e, C28 - AliExpress