Panasonic P-P304 Cordless Phone Replacement Battery 3.6V 600mAh

Panasonic P-P304 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 600mAh Ni-MH replacement battery for Panasonic cordless phone handsets that use the P-P304 pack. It fits units also cross-referenced as PP304, P-P304PA/1B, and TYPE 9. When your handset stops holding charge, this pack restores full function without replacing the phone.

• P-P304 platform coverage: Panasonic cordless handsets in this series share the same 3.6V NiMH cell configuration, connector pinout, and physical envelope — all cross-reference numbers (PP304, P-P304PA/1B, TYPE 9) point to the same electrical spec and slot into the same battery compartment.
• 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 anomaly, and voltage held within spec across the discharge curve.
• First-charge protocol for NiMH cordless packs: After installing, seat the handset in the base and leave it for a full 16 hours before using the phone. NiMH cells shipped in a partially discharged state need one slow, uninterrupted charge to reach rated capacity — skipping this step is the most common reason buyers report short talk time on a new battery.

Base station showing charging error on a new NiMH pack

Panasonic base stations check incoming battery voltage before initiating the charge cycle. A NiMH pack that has self-discharged below roughly 3.0V during storage may fall outside the base's acceptance window, triggering an error light or no-charge state. The fix is not a faulty battery — it's a depleted one. Some bases recover automatically once the pack voltage rises slightly; if yours does not, a brief charge via a compatible external NiMH charger set to the correct cell count will bring voltage up to the threshold the base expects.

Range drops noticeably after a battery swap

DECT handsets regulate transmit power from the battery rail. When a NiMH pack is not yet fully conditioned, voltage sags under the RF load of an active call, and the handset scales back transmit power to compensate. This shows up as reduced range or audio drop-outs, particularly at the edges of your coverage area. Run three to five full charge-and-use cycles — each cycle brings the cells closer to rated capacity — and the voltage sag under RF load will decrease. After cycle five, check range again at the same distance where drop-outs occurred.