Sony VGF-WA1 Replacement Battery 11.1V 2600mAh Li-ion

Sony VGF-WA1 — 11.1V Li-ion Replacement Battery (6ZO4A)

This is an 11.1V, 2600mAh Li-ion replacement battery for the Sony VGF-WA1 portable Bluetooth speaker. It replaces OEM part number 6ZO4A directly. Fit the battery when your original pack no longer holds charge or cuts out during audio playback.

• VGF-WA1 voltage rail match: The VGF-WA1 amplifier and Bluetooth radio draw from a shared 11.1V bus. A battery that sags under combined amp and radio load triggers the protection circuit and shuts the speaker mid-session. This pack holds voltage across both loads without tripping the BMS at normal listening levels.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the VGF-WA1 motherboard. The BMS handshake completed correctly, the fuel gauge reported accurate state-of-charge, and the pack accepted a full charge without thermal event.
• Monthly discharge cycle for VGF-WA1: If you use this speaker at a desk or fixed location, it is likely topped off constantly before dropping below 50%. Run the speaker down below 20% at least once a month before recharging. Without a periodic full discharge, the fuel gauge drifts and the cell develops shallow-cycle capacity fade faster than normal Li-ion aging curves.

Why the VGF-WA1 shows full charge but audio cuts after an hour

The VGF-WA1 fuel gauge reads state-of-charge from a coulomb counter that relies on seeing a full discharge to recalibrate. If the pack has only ever been shallow-cycled, the counter drifts upward and reports more charge than the cell actually holds. The speaker then shuts down from undervoltage while the indicator still shows bars. A full discharge to the BMS cutoff floor — around 9V at the battery terminals — resets the calibration. After one full cycle, the indicator and actual runtime align again.

Audio distorting before the battery indicator reaches empty

As the VGF-WA1 battery discharges toward its lower threshold, internal resistance rises and voltage sags under the amplifier's current demand. The amplifier clips when supply voltage drops below what it needs to deliver clean output — this shows up as distortion well before the BMS triggers a full shutdown. The battery indicator is tied to resting voltage, not load voltage, so it lags behind what the amp actually sees under draw. If you hear clipping at moderate volume near the end of a charge, charge the pack immediately rather than continuing to play at reduced volume.