Audioline DECT 5500 Replacement Battery 2.4V 450mAh

Audioline DECT 5500 Series — 2.4V Ni-MH Replacement Battery (30AAAAH2BX)

This is a 2.4V, 450mAh Ni-MH rechargeable battery for the Audioline DECT 5500 handset. It fits the DECT 5500, DECT 5501, DECT 5800, and DECT 550 cordless phone handsets. It replaces OEM part numbers 30AAAAH2BX and T323.

• DECT 5500 series compatibility: These handsets share the same 2.4V dual-cell NiMH battery bay, connector pitch, and charge circuit. The base station charges at a trickle rate matched to this chemistry, so swapping in a lithium pack would damage the charge circuit.
• Bench tested on actual hardware: We cycled this battery through charge and discharge on a DECT cordless handset platform. The BMS accepted the NiMH pack without error, and the base station charge indicator lit correctly from the first seating.
• First charge on DECT NiMH packs: After installing, seat the handset in the base and leave it for a full 16 hours before first use. NiMH cells in cordless phones are shipped partially discharged. A slow first charge lets each cell reach equal voltage and hit rated capacity — skipping this step leaves noticeable capacity on the table for the first several cycles.

Why talk time stays short for the first few cycles on a new NiMH pack

NiMH cells don't deliver full rated capacity straight out of storage. The crystalline structure inside each cell needs two to five full charge-discharge cycles before it reaches 450mAh. If talk time feels short after the first charge, that's expected — not a fault. Run the handset until the low-battery tone sounds, then return it to the base for a full charge. Repeat this two more times and capacity will stabilise at the rated level.

Base station charge light not activating after battery swap

If the base station shows no charge indicator after fitting the new battery, the NiMH pack voltage is likely below the base's acceptance threshold from extended storage. The charge circuit on DECT bases uses a delta-V detection method — it needs the battery to present a minimum resting voltage before it begins charging. Remove the handset, wait 30 seconds, then reseat it firmly so both charge contacts make full contact. If the light still doesn't activate, check the resting voltage across the battery terminals — it should read at least 2.0V for the base to begin the charge cycle.