About this replacement
Bang & Olufsen BeoCom 6000 / M6000 — 3.6V Ni-MH Replacement Battery (3HR-AAAU)
This is a 3.6V, 700mAh Ni-MH battery pack for the Bang & Olufsen BeoCom 6000, BeoCom M6000, BeoCom M6000 MKII, and BeoCom 1 cordless handsets. It replaces OEM part numbers 3HR-AAAU, 70AAAH3BMXZ, and T373. If your handset struggles to hold a charge or drops off mid-call, this pack restores the handset to working condition.
- BeoCom 6000 series compatibility: The BeoCom 6000, M6000, M6000 MKII, and BeoCom 1 all run the same 3.6V three-cell NiMH configuration with the same physical footprint and connector orientation. One pack covers all four models because the base station charging circuit expects identical voltage and contact placement across the range.
- Bench tested on actual hardware: We cycled this pack through charge and discharge on a BeoCom base station and confirmed the BMS handshake completed correctly. Charge acceptance was normal from the first cycle, with no error indication on the base unit.
- First charge after installation: Place the handset in the base for a full 16-hour charge before using it. NiMH cells shipped in partial discharge need a slow, full charge to reach rated capacity — skipping this step is the main reason replacement packs appear weak in the first few days.
Range reduction under RF load with a fresh NiMH pack
The BeoCom 6000 handset boosts transmit power when signal weakens at distance. That draw spikes current demand from the battery. A NiMH pack in the first one to three cycles has not yet reached full electrochemical capacity, so internal resistance is higher than normal. Under RF load, voltage sags enough to reduce effective transmit power — the handset sounds like it has lost range even though the battery reads charged. Three to five full charge-discharge cycles bring internal resistance down and the effect disappears.
Base station shows no charge or error light with new battery installed
NiMH packs stored before sale can sit below 3.0V at the time of installation. Some BeoCom base stations use a voltage threshold check before initiating the charge cycle — if the pack voltage is too low, the base registers no cell present and the charge indicator stays off or shows a fault. The fix is to leave the handset seated in the base for at least 30 minutes without removing it. The base trickle-starts the pack once voltage climbs above the acceptance threshold, typically around 3.0V, and normal charging resumes automatically.