ClearOne Max 7.2V Ni-MH Replacement Battery 220AAH6SMLZ

ClearOne Max / Max Wireless — 7.2V Ni-MH Replacement Battery (220AAH6SMLZ)

This is a 7.2V, 2000mAh Ni-MH replacement battery for ClearOne Max and Max Wireless conferencing systems. It fits models 592-158-003 and 592-158-001, among others. The OEM part number is 220AAH6SMLZ.

• Max and Max Wireless compatibility: Both models share the same 7.2V battery rail, connector pinout, and BMS handshake protocol. One pack covers the full family — no adapters or firmware changes needed.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a Max Wireless unit. The BMS accepted the pack immediately, reported cell voltage correctly, and held a steady output under combined audio and wireless transmitter draw without triggering low-voltage cutoff.
• First-session calibration tip: After installing, run a complete charge cycle before your first meeting. The Max series maps battery state against voltage thresholds during normal operation. A fresh pack that hasn't completed one full cycle may display inaccurate charge warnings for the first session — this corrects itself after that initial cycle.

Wireless connection drops under combined audio and transmitter draw

The Max Wireless unit runs both an audio processing circuit and a wireless transmitter from the same 7.2V cell stack. When the pack is aged or stored for months before installation, internal resistance climbs. Under that combined load, voltage sags briefly below the radio module's operating threshold — enough for the wireless link to drop even though the unit still appears powered. This is different from a dead battery; the unit looks fine at rest but cuts out during active use. Fitting a new pack with low internal resistance eliminates the sag, and the connection holds through the full session.

Charging dock not recognising a freshly installed pack

If the dock LED doesn't change state after seating the unit, the most common cause is contact resistance between the battery terminals and the dock's charge pins — not a faulty pack. Storage dust and oxidation on the gold contacts can block the low-current sense signal the dock uses before it begins charging. Remove the unit, wipe the battery contacts and dock pins with a dry cloth, then reseat firmly. If the dock still doesn't respond, check that pack voltage is above 5.0V with a multimeter — a pack that dropped below that threshold during storage may need a conditioning charge before the dock will accept it.