Thomson PDP2840 MP3 Player Compatible Battery 3.7V 1600mAh

Thomson PDP2840 MP3 Player — 3.7V Li-ion Replacement Battery (PMPTH2840)

This is a 3.7V, 1600mAh Li-ion replacement battery for the Thomson PDP2840 MP3 player. It slots into the same bay as the original cell and connects via the factory connector. Capacity is 1600mAh (5.92Wh) — matching the stock specification.

• PDP2840 fitment: The PDP2840 uses a flat Li-ion cell at 3.7V nominal. The BMS in this player monitors cell voltage directly — a mismatch in voltage or connector pinout trips a protection fault and the player won't power on. This cell matches both.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a controlled load. The BMS accepted charge current without flagging an error, and the protection circuit tripped correctly at the low-voltage cutoff threshold — no soft lock, no stuck charging state.
• First charge after a long-storage swap: If this cell has sat in a warehouse, its resting voltage may have dropped below the player's wake threshold. Connect the charger before pressing power. Leave it connected for at least 30 minutes — the player's charge controller needs to trickle-charge the cell back above the minimum detection voltage before it accepts normal charge current.

Battery percentage jumping around after a cell swap

The PDP2840 estimates remaining charge by reading cell voltage against a fixed lookup table stored during the original factory calibration. A new cell has a slightly different voltage-to-capacity curve than a degraded old one, so the indicator mis-reads the state of charge until the table recalibrates. Run the battery down to the auto-shutoff point, then charge it in a single uninterrupted session to 100%. One full cycle is usually enough for the percentage display to stabilise.

Playback cuts out before the battery indicator shows empty

The audio amplifier in the PDP2840 draws a short current spike every time the output stage switches — this happens thousands of times per second during playback. Near the end of discharge, the cell's internal resistance rises, and those spikes cause the terminal voltage to dip below the amplifier's minimum operating voltage for a split second. The player interprets this as a hard undervoltage event and shuts down, even though the indicator still shows residual charge. This is not a fault with the new cell — it is the player's protection logic responding to voltage sag. A fully charged cell will push this cutoff point much further into the discharge curve.