Apple iPOD shuffle 5th Replacement Battery 3.7V 50mAh

Apple iPod shuffle 4th & 5th Generation — 3.7V Li-Polymer Replacement Battery (616-0150)

This 3.7V, 50mAh Li-Polymer battery replaces the original cell in the Apple iPod shuffle 4th and 5th generation compact media players. It matches OEM part numbers 616-0150 and 616-0548. When the original cell degrades and the player fails to hold a charge, this replacement restores full power capacity.

• iPod shuffle 4th and 5th generation fit: Both generations share the same internal PCB layout, connector pinout, and BMS handshake protocol. One cell covers both platforms without modification.
• Bench tested on actual hardware: We ran this cell through charge cycles on a 5th generation unit. The BMS accepted the cell without error flags and completed full charge cycles at the expected termination voltage.
• Post-swap charging protocol: After installing a new cell, connect the iPod to iTunes via USB before attempting playback. The shuffle's firmware re-reads the cell state on the first USB handshake and sets the charge baseline — skipping this step can leave the capacity indicator miscalibrated from the first use.

Why the iPod shuffle won't wake after sitting unused for months

The shuffle's BMS enters deep-discharge lockout when cell voltage drops below approximately 2.5V during extended storage. In this state, the player shows no response to the power switch. The fix is to connect the player to a USB power source and leave it for at least 30 minutes before attempting to power on — this allows the trickle pre-charge circuit to bring the cell back above the BMS re-enable threshold of around 3.0V.

Battery percentage jumping erratically after a cell swap

The iPod shuffle uses a voltage-threshold method to estimate charge level — it does not track coulombs. After fitting a new cell, the firmware's stored voltage-to-percentage map no longer matches the new cell's discharge curve. This causes the indicator to jump or read incorrectly during the first few cycles. Run two to three full charge and full discharge cycles through iTunes-connected USB to let the firmware recalibrate the thresholds against the new cell's actual voltage profile.