DeTeWe OpenPhone 21 Ni-MH Compatible Battery 2.4V 700mAh

DeTeWe OpenPhone 21 / Eurix Series — 2.4V Ni-MH Replacement Battery (NS-3098)

This is a 2.4V, 700mAh Ni-MH replacement battery for the DeTeWe OpenPhone 21 and compatible Eurix series cordless handsets. It replaces OEM part numbers NS-3098 and BC101590. When the original pack no longer holds a charge, this restores handset operation without replacing the phone system.

• OpenPhone 21, Eurix Style, Eurix 260, and Eurix 260 Style compatibility: These handsets share the same 2.4V battery rail, connector footprint, and BMS handshake protocol. One pack fits across the range because the charging circuit and cell format are identical across this DeTeWe cordless platform.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on compatible handset hardware. The BMS accepted the NiMH cells without fault, reached full charge voltage cleanly, and the handset registered a full charge indicator within the expected window.
• First-charge conditioning for NiMH cordless packs: After installing, seat the handset in the base and leave it for a full 16 hours before the first use. NiMH cells in cordless phones need this slow initial charge to reach rated capacity — cutting it short means the first several cycles will run short.

Talk time shorter than rated after replacing the battery

NiMH cordless phone batteries do not reach full rated capacity on cycle one. The electrochemical structure needs three to five full charge-discharge cycles before the cells hit their rated 700mAh. If talk time seems short after the first charge, this is normal — not a fault. Run the handset until the low-battery alert sounds, return it to the base for a full charge, and repeat for at least three cycles.

Base station showing no charge or error light after inserting new battery

NiMH packs lose voltage during storage. If the cell voltage drops far enough, the base station's charging circuit may read the pack as faulty and refuse to charge it. This is a threshold issue, not a battery defect. Place the handset firmly in the cradle and leave it undisturbed for at least two hours — most DeTeWe bases will begin trickle charging below the normal acceptance voltage and recover the pack to a level where normal charging resumes. If the error persists after two hours, reseat the handset and check the contacts on both the handset and cradle are clean and making solid contact.