Panasonic P-P502 Cordless Phone Replacement Battery 3.6V 1200mAh

Panasonic P-P502 / TYPE 10 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 1200mAh Ni-MH replacement battery for Panasonic cordless phone handsets using the P-P502 or TYPE 10 pack. It fits handsets that run independently from the base station on a single rechargeable cell pack. The dimensions are 50.43 × 42.54 × 14.40mm — measure your existing pack before ordering if you are unsure.

• P-P502 and TYPE 10 handsets: Both part numbers reference the same cell configuration — 3.6V nominal, three AAA Ni-MH cells in series. The connector pinout and physical housing match across Panasonic handsets that carried either designation from the factory.
• Bench tested on actual hardware: We ran charge and discharge cycles through a Panasonic base station cradle. The BMS accepted charge without error from cycle one. Full capacity was not reached until cycle three — this is normal Ni-MH behaviour, not a fault.
• First charge after installation: Place the handset in the base immediately after fitting this battery and leave it for a full 16 hours before the first call. Ni-MH cells in cordless handsets need a slow initial charge to reach rated 1200mAh capacity — a quick top-up charge will leave you with noticeably shorter talk time on early cycles.

Range dropping mid-call after a battery swap

DECT handsets draw a sharp current spike each time the RF module transmits. A freshly installed Ni-MH pack that has not completed conditioning cycles has higher internal resistance than a broken-in cell. That resistance causes voltage to sag under transmit load, which the handset reads as low battery and steps down transmit power. After three to five full charge and discharge cycles, internal resistance drops and the voltage holds steady under RF load.

Base station charge light stays off or shows an error after fitting a new pack

Ni-MH packs sitting in warehouse storage can self-discharge to below 3.0V over several months. Some Panasonic base stations will not initiate a charge cycle if the pack voltage is too low — the base expects at least 3.2–3.4V to confirm a valid cell is present. To recover the pack, connect it briefly to a universal Ni-MH charger at a low trickle rate (around 100mA) until voltage climbs above 3.3V. Once the base station detects that threshold, normal charging resumes.