About this replacement
Sony SRS-XP500 Series — 14.8V Li-ion Replacement Battery (IAA042GA)
This is a 14.8V, 3000mAh (44.4Wh) Li-ion replacement battery for the Sony SRS-XP500 and SRS-XP500B portable Bluetooth speaker. It replaces OEM part numbers IAA042GA and 9-301-009-76. Fit this battery when the original no longer holds a charge or powers the speaker through a full session.
- SRS-XP500 and SRS-XP500B compatibility: Both variants run the same 14.8V battery rail, use the same connector, and share the same BMS handshake protocol — one battery covers both models without modification.
- Bench tested on actual hardware: We cycled this battery through charge and discharge on the SRS-XP500 platform. The BMS accepted charge without fault codes, held voltage under combined amplifier and Bluetooth radio draw, and reported state-of-charge accurately through the speaker's indicator.
- Monthly discharge cycle for the SRS-XP500: Speakers left on a desk and topped off before dropping below 50% develop fuel gauge drift fast. Run the SRS-XP500 down below 20% at least once a month before recharging — this keeps the cell chemistry and the charge indicator calibrated.
Audio distorting before the battery indicator reaches empty on the SRS-XP500
The SRS-XP500 amplifier draws a sharp current spike at high volume. When the battery voltage sags under that load, the amplifier hits its lower voltage threshold before the battery indicator reads empty. The result is clipping and distortion — the speaker sounds broken, but the battery indicator still shows charge remaining. If you hear distortion at high volume, lower the volume first to confirm the battery is the cause; distortion that clears at lower volume points to voltage sag, not a driver fault.
SRS-XP500 not waking from USB-C charge after sitting unused for weeks
A deeply discharged Li-ion cell can drop below the minimum acceptance voltage for USB-C Power Delivery, so the charger sees nothing to negotiate with and the speaker stays dark. The BMS blocks charge input as a protection measure when the cell voltage falls too low. To recover the pack, connect a compatible USB-C charger rated at least 18W and leave it undisturbed for 20–30 minutes — the BMS on this battery includes a trickle pre-charge stage that brings the cell back up to the PD acceptance threshold before switching to full charge. If the indicator still does not light after 30 minutes, check that the charger output is at least 14.5V DC.