National ES094 Media Player Replacement Battery 1.2V 1200mAh

National ES094 — 1.2V Ni-MH Replacement Battery

This is a 1.2V 1200mAh Ni-MH replacement battery for the National ES094 portable media player. It restores power to devices where the original cell has degraded or lost capacity. Voltage and capacity match the original spec exactly.

• ES094 cell fit: The ES094 uses a single Ni-MH cell at 1.2V nominal — the standard discharge voltage for this chemistry. The replacement cell matches the original's dimensions (66.78 × 16.70 × 5.96mm), so it seats correctly in the battery compartment without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench. The cell accepts charge current normally, holds voltage through mid-cycle, and drops off at the expected low-voltage knee without triggering protection cutoff prematurely.
• First charge after a cell swap: Media players running Ni-MH cells often enter a deep-discharge protection state when a new cell is installed. Connect the charger and leave it for at least 30 minutes before attempting to power on — the device needs trickle current first before it will accept a normal charge cycle.

Playback cutting out before the battery indicator shows empty

Ni-MH cells have a relatively flat discharge curve, but voltage sags under the load of an audio amplifier near the end of a cycle. The ES094's playback circuit pulls more current than the idle display, which accelerates voltage drop in the final 10–15% of charge. When voltage falls below the amplifier's minimum rail, audio cuts out even though the battery indicator still reads low-but-not-empty. Run two or three full charge-discharge cycles to let the cell settle — this tightens the voltage curve and makes the cutoff more predictable.

Battery percentage jumping erratically after installing this cell

The ES094's fuel gauge reads battery level by measuring cell voltage against stored thresholds calibrated to the old cell's wear state. A fresh cell has a different voltage profile, so the indicator recalibrates over the first few cycles and can jump or misread during that period. This is not a fault with the replacement cell. Run the device from a full charge down to auto-off, then charge fully — repeat this two or three times and the percentage display will stabilise around 1.2V nominal.