Sylvania 39230 Replacement Battery 3.6V 1200mAh Ni-MH

Sylvania 39230 / 39370 — 3.6V Ni-MH Replacement Battery

This 3.6V, 1200mAh Ni-MH battery replaces the factory pack in the Sylvania 39230 and 39370 cordless handsets. It restores standby and talk time lost to cell degradation in older packs. Physical dimensions are 50.43 × 42.54 × 14.40mm — check your existing pack before ordering.

• 39230 and 39370 compatibility: Both models run the same 3.6V three-cell Ni-MH pack with identical connector pin-out and compartment dimensions. One replacement covers either handset without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a Sylvania 39230 handset. The base station accepted the new pack without a charging error, and cell voltage stabilised correctly across all three cells by the third cycle.
• 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 first use. Ni-MH cells shipped from storage are partially discharged — a slow initial charge lets all three cells equalise and reach rated capacity.

Talk time shorter than original battery after replacement

New Ni-MH packs rarely hit rated capacity on the first cycle. The cells need three to five full charge-discharge cycles before the chemistry reaches its working range. Each cycle, capacity steps up noticeably. If talk time is still short after five cycles, check that the handset sits flush in the base — poor contact reduces charge current and leaves cells undercharged.

Handset not pairing with base after battery swap

Removing the old battery cuts power completely to the handset's DECT module, which can wipe the stored pairing. The fix is straightforward: hold the handset's Paging or Find button while pressing the Locator button on the base for three seconds. Most Sylvania DECT handsets re-register within 30 seconds. Once paired, confirm the handset shows a signal bar before returning it to the base.