Aastra DS-900 Cordless Phone Replacement Battery 3.6V 1500mAh

Aastra DS-900 / JB-900 / ME-900 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 1500mAh Ni-MH battery for the Aastra DS-900, JB-900, ME-900, and PMG-3455 cordless phone handsets. It replaces the original pack when the handset no longer holds a charge through a normal day of calls and standby. Physical dimensions are 50 x 42 x 14mm — verify clearance in your handset before ordering.

• DS-900 / JB-900 / ME-900 platform fit: These four models share the same handset battery bay dimensions, cell count, and connector orientation. A single 3.6V, three-cell Ni-MH pack covers all of them — no adapter or wiring change needed.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the DS-900 platform. The base station accepted the pack without error, and voltage held steady across the RF transmit bursts typical of DECT handsets.
• First-charge protocol for Ni-MH cordless packs: After installing, seat the handset in the base and leave it for a full 16 hours before making any calls. Ni-MH cells shipped from storage are partially discharged — a slow first charge is what lets them reach rated 1500mAh capacity.

Talk time shorter than the original battery after replacement

Ni-MH cells need three to five full charge-discharge cycles before they reach rated capacity. A new pack pulled from storage will underperform on the first day — this is chemistry, not a fault. Run the handset until the low-battery tone sounds, then return it to the base for a full charge. Repeat that cycle four times and capacity will stabilise at the rated 1500mAh.

Base station charge light not activating on a freshly installed pack

Some Aastra base stations use a voltage threshold to confirm a valid battery before starting the charge circuit. A pack that has self-discharged below roughly 3.0V during storage may sit below that threshold. Remove the handset, wait 10 seconds, then re-seat it firmly — the contact pressure resets the detection circuit. If the light still does not activate, check that the handset contacts and base contacts are clean and free of oxidation.