Astro Gaming Mixamp 4.8V Replacement Battery AC40-AG-1060

Astro Gaming Mixamp — 4.8V Ni-MH Replacement Battery (AC40-AG-1060)

This is a 4.8V, 2000mAh Ni-MH replacement battery for the Astro Gaming Mixamp wireless audio amplifier. It fits the Mixamp directly, restoring wireless functionality and audio amplification when the original cell no longer holds a usable charge. OEM part numbers AC40-AG-1060 and 3ABAT-XXT9U-929 both apply to this unit.

• Mixamp wireless platform fit: The Mixamp runs a 4.8V Ni-MH cell pack at a specific connector pinout tied to its charge management circuit. This battery matches that voltage rail and connector, so the Mixamp's onboard charge IC recognises and cycles the cell correctly without modification.
• Bench tested on actual hardware: We ran this cell through the Mixamp's charge and discharge circuit on the bench. The BMS accepted the cell without fault flags, completed a full charge cycle, and held the voltage rail steady under audio amplification load.
• First-cycle calibration on the Mixamp: After installing, run one complete wireless session to full automatic cutoff before recharging. The Mixamp's fuel gauge sets its empty reference point against the first full discharge cycle — skipping this step causes the indicator to read inaccurately from the start.

Why the Mixamp charge IC applies a conservative rate on a new cell

Ni-MH charge management circuits use delta-V detection to find the charge termination point. On a brand-new cell, the internal resistance profile differs from a conditioned pack, so the IC reads the voltage slope more cautiously and may throttle the charge current on the first one or two cycles. This is normal behaviour — not a fault with the battery or the unit. After two to three full charge-discharge cycles, the cell's discharge curve settles and the charge IC runs at its full programmed rate.

Mixamp battery indicator jumping or showing full immediately after swap

If the charge indicator reads full straight after installation — or jumps between levels during use — the fuel gauge IC hasn't mapped the new cell's discharge curve yet. Ni-MH gauges calibrate against actual voltage drop over a discharge cycle, not a stored value. A full discharge to automatic cutoff followed by a complete recharge resets the reference point. After that first full cycle, the indicator should track remaining charge accurately.