Universel AAA x 4 Cordless Phone Replacement Battery 4.8V 700mAh

Universel AAA x 4 Cordless Phone — 4.8V Ni-MH Replacement Battery

This is a 4.8V, 700mAh Ni-MH battery pack built from four AAA cells. It fits cordless DECT handsets that take a quad-AAA configuration. If your handset no longer holds charge or the original pack has failed, this is the direct cell-for-cell replacement.

• Quad-AAA cordless phone packs: Cordless handsets using this configuration share a common 4.8V rail and physical footprint. The four cells are wired in series to match the voltage the handset's charging circuit expects. Swapping one undersized or mismatched cell would throw off the whole pack — all four must be matched, which this unit delivers.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a DECT handset base station. The BMS accepted the Ni-MH voltage curve without triggering a charge error, and the cells balanced across all four positions within the first two full cycles.
• First charge on 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 arrive partially discharged from storage. A slow, uninterrupted first charge lets all four cells reach rated capacity together rather than staggering.

Base station showing a charging error on a new Ni-MH pack

Some DECT base stations use a delta-V detection circuit to confirm charging has started. A Ni-MH pack that has self-discharged during storage may sit below the voltage threshold the base expects to see before it begins the charge cycle. The base interprets this as a fault and throws an error light instead of charging. To clear it, remove the handset, leave it out for 30 seconds, then reseat it firmly — this forces the base to re-poll the battery voltage. If the error persists, check that the handset contacts are clean and the pack is reading at least 3.6V before insertion.

Range drops noticeably after fitting a new battery

DECT transmit power draws a short but sharp current spike every time the handset communicates with the base. If the Ni-MH pack is not yet fully conditioned, internal resistance across the four cells causes voltage to sag under that RF load. The handset's transmit circuit backs off power to compensate, and range shrinks. Run three to five full charge-and-discharge cycles and the internal resistance drops — range returns to normal once the cells are properly conditioned.