Hagenuk AIO 600 Cordless Phone Replacement Battery 2.4V 850mAh

Hagenuk AIO 600 — 2.4V Ni-MH Replacement Battery (CN03045TS)

This is a 2.4V, 850mAh Ni-MH replacement battery for the Hagenuk AIO 600 cordless phone handset. It slots into the handset battery compartment and restores wireless operation when the original pack no longer holds charge. Dimensions are 49.89 × 33.24 × 6.15mm — confirm these against your existing pack before ordering.

• AIO 600 handset fit: The AIO 600 handset runs a 2.4V dual-cell Ni-MH pack at this exact form factor. The base station charges via contact pins calibrated for Ni-MH voltage curves — swapping chemistry or voltage would break the charge cycle entirely.
• Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on a Ni-MH compatible tester. The BMS-free Ni-MH chemistry accepted a slow trickle charge correctly and delivered consistent voltage across the discharge curve with no premature cutoff.
• First-charge protocol for Ni-MH handsets: After installing, seat the handset in the base and leave it for a full 16 hours before the first use. Ni-MH cells in cordless phones require this slow initial charge to reach rated capacity — pulling it off early on the first cycle will permanently reduce how much charge the pack accepts.

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

A freshly shipped Ni-MH battery typically arrives at a low state of charge — sometimes below 1.8V per cell. Some AIO 600 base stations interpret this low voltage as a faulty or missing pack and flag an error light rather than beginning a charge cycle. The fix is straightforward: place the handset in the base without touching it for 20–30 minutes. The base's trickle-start circuit will raise the cell voltage enough to trigger the normal charge acceptance threshold, usually around 2.0V total, at which point the error clears and full charging begins.

Range drops noticeably during a call after the battery swap

The AIO 600 handset's DECT radio draws a surge of current each time it transmits a signal burst. If the Ni-MH pack hasn't been fully conditioned yet, its internal resistance is higher than normal, and voltage sags under that RF load. The handset interprets low voltage as a weak signal and reduces transmit power, which cuts effective range. Run three to five full charge and discharge cycles through the handset — internal resistance drops with each cycle and voltage sag under transmit load reduces, restoring normal range.