Creative Zen Sleek 3.7V Replacement Battery 1050mAh Li-Polymer

Creative Zen Sleek / Zen Sleek Photo — 3.7V Li-Polymer Replacement Battery (BA20603R79915)

This is a 3.7V, 1050mAh Li-Polymer replacement battery for the Creative Zen Sleek, Zen Sleek Photo, and DAP-HDD019 portable media players. It replaces OEM part number BA20603R79915. If your Zen Sleek won't hold a charge or fails to power on, this is the direct cell swap.

• Zen Sleek, Zen Sleek Photo, DAP-HDD019 compatibility: All three share the same 3.7V Li-Polymer cell format, connector pinout, and BMS communication protocol — one battery covers the full range without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on Zen Sleek hardware. The BMS accepted the cell without error, held the charge curve cleanly, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• First charge after deep storage: If your player has been sitting unused for months, connect it to the charger and leave it for at least 30 minutes before attempting to power on. Media players often enter a deep discharge protection state that requires a slow trickle current before the BMS accepts a normal charge cycle.

Battery percentage jumping erratically after cell swap

After fitting a new cell, the Zen Sleek's on-screen battery indicator often shows erratic percentage readings — jumping from 80% to 20% without warning. This happens because the firmware's voltage-to-percentage lookup table is calibrated against the old, degraded cell's discharge curve. The new cell has a flatter discharge curve and higher resting voltage at equivalent states of charge, so the indicator loses its reference points. Run two full charge and discharge cycles and the readings will stabilise as the firmware recalibrates its thresholds.

Playback cutting out before the battery indicator shows empty

The Zen Sleek's audio amplifier draws a brief current spike during playback — particularly at higher volume levels — that can pull cell voltage below the BMS cutoff threshold before the battery gauge reaches zero. This voltage sag is more pronounced at the tail end of a discharge cycle when internal cell resistance is highest. If playback stops but the unit restarts immediately on reconnecting the charger, voltage sag is the cause. Keep volume below 80% during the last portion of battery charge to keep the draw within the cell's stable delivery range.