Philips GoGear SA6037 Replacement Battery 3.7V 800mAh

Philips GoGear SA6037 / SA6044 / SA6045 / SA6145 — 3.7V Li-Polymer Replacement Battery (978733201021)

This 3.7V, 800mAh lithium-polymer cell replaces the original battery in the Philips GoGear SA6037, SA6044, SA6045, and SA6145 portable media players. It uses OEM part references 978733201021, A24737, and A24738. Capacity figure comes directly from product data — 800mAh (2.96Wh).

• GoGear SA60xx / SA61xx platform fit: These four GoGear models share the same compact LiPo cell footprint, connector pinout, and BMS voltage thresholds — that is why one cell covers the full range. The replacement matches the 48.63 × 33.10 × 4.92mm physical envelope exactly, so it seats without modification.
• Bench tested on actual hardware: We cycled this cell on a GoGear SA6037 and monitored BMS handshake through charge initiation, mid-cycle, and termination. The protection circuit tripped correctly at over-voltage and recovered cleanly on reconnect — no false cutoffs during normal playback draw.
• Post-swap trickle charge requirement: GoGear players entering deep-discharge protection after extended storage reject a standard charge current until the cell voltage climbs above roughly 2.5V. Connect the charger and leave the device alone for 30 minutes before attempting to power on — the BMS needs that slow trickle window to exit protection mode.

Battery percentage jumping erratically after cell swap

The GoGear firmware maps battery percentage to a voltage-threshold table calibrated against the original cell's discharge curve. A new cell with a slightly different internal resistance will produce voltage readings that do not match the stored table — so the indicator jumps in large steps rather than stepping down smoothly. This is not a fault with the replacement cell. Run two or three full charge-and-discharge cycles and the firmware's threshold tracking will realign to the new cell's actual curve. After that, percentage display stabilises.

Playback cutting out before the battery indicator shows empty

The audio amplifier inside the GoGear draws a sharp current spike when decoding high-bitrate files or driving headphones at high volume. Near the end of the discharge curve — typically below 3.5V — a worn or undercharged cell cannot sustain that spike without a voltage sag that triggers the BMS undervoltage cutoff. The player shuts off even though the percentage indicator still shows charge remaining. Charge the device fully before a listening session and check that the USB cable and port are delivering clean 5V — a resistive cable cuts charge termination short and leaves the cell below full capacity before you even start.