AT&T 17 Cordless Phone Replacement Battery 2.4V 1500mAh

AT&T 17 / 50 — 2.4V Ni-MH 1500mAh Replacement Battery

This is a 2.4V, 1500mAh Ni-MH battery pack for the AT&T cordless phone models 17 and 50. It slots into the handset and powers both active calls and standby operation. Capacity is sourced from the product spec — 1500mAh at 3.6Wh.

• AT&T 17 and 50 compatibility: Both models share the same 2.4V dual-cell NiMH architecture and identical battery bay dimensions (50.80 × 28.05 × 14.44mm), so one pack covers either handset without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a NiMH-compatible test rig. The cells accepted a full charge without thermal runaway, and voltage held steady across standby and active-call load simulation.
• First-charge requirement for NiMH cordless packs: After installing, seat the handset in the base and leave it there for a full 16 hours before use. NiMH cells ship in a partially discharged state — skipping this slow first charge means the pack never reaches rated capacity.

Talk time shorter than the original battery after replacement

NiMH cells need three to five full charge-discharge cycles before they hit rated capacity. A brand-new pack will underperform the original for the first few days of use — this is normal cell chemistry, not a defect. Each full cycle lets the cells form properly and hold more charge. By cycle five, capacity should be at or near the rated 1500mAh.

Base station showing no charge or error light with new pack installed

NiMH batteries lose voltage during storage, and some AT&T base stations reject packs sitting below their acceptance threshold — typically around 2.0V for a 2.4V pack. The base reads the low voltage as a fault rather than a depleted cell. To recover, leave the handset seated in the base undisturbed for at least two hours — most chargers will trickle-prime a low pack before switching to full charge. If the error light clears, the pack is accepting charge normally.