Toshiba Gigabeat MES30VW Compatible Battery 3.7V 1000mAh

Toshiba Gigabeat MES30VW / MES60V Series — 3.7V Li-ion Replacement Battery (1UPF383450-TBF)

This 3.7V 1000mAh Li-ion battery replaces the original cell in the Toshiba Gigabeat MES30VW, MES30V, MES60V, and MES60VK portable media players. It matches OEM part numbers 1UPF383450-TBF, K33A, and 1UPF383450-830. At 53.18 x 34.23 x 4.26mm, it fits the original bay without modification.

• Gigabeat MES30V / MES60V platform fit: These four models share the same 3.7V single-cell architecture, connector pinout, and BMS handshake protocol. One cell revision covers all four variants without rewiring or adapter hardware.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Gigabeat platform. The BMS accepted the charge curve without triggering false low-voltage cutoff, and the protection circuit responded correctly at cell termination voltage.
• First-charge protocol for Gigabeat players: If the player shipped or was stored flat, connect it to the charger for at least 30 minutes before pressing power. The Gigabeat firmware holds the device in deep-discharge protection and won't respond to the power button until the cell climbs above the minimum wake threshold — approximately 3.0V.

Battery percentage jumping erratically after cell swap on Gigabeat MES series

The Gigabeat fuel gauge reads voltage thresholds, not true coulomb counting. After a cell swap, the firmware's stored discharge curve no longer matches the new cell's actual voltage profile. This causes the percentage indicator to jump — sometimes dropping 20% in seconds, then holding flat for long stretches. Run two or three full charge-to-discharge cycles and the gauge recalibrates to the new cell's curve. By the third cycle, readings stabilise.

Playback cutting out before the battery indicator reaches empty

The audio amplifier in the Gigabeat MES series draws a brief current spike when decoding high-bitrate video or driving headphones at high volume. Near end of discharge, the aged or depleted cell can't hold voltage under that momentary load, and the BMS trips the output to protect the cell. The display may show 10–15% remaining at the moment of cutoff. Charge the battery fully — to 4.2V — before the next session, and the cell will handle those load spikes without tripping early.