About this replacement
Coby TFDVD7752 — 7.4V Li-Polymer Replacement Battery (AHB772992P-2S)
This is a 7.4V, 2600mAh lithium-polymer battery for the Coby TFDVD7752 portable DVD player. It replaces part number AHB772992P-2S and restores the player's ability to run on battery power away from a wall outlet. Dimensions are 96.10 x 31.00 x 16.50mm — confirm these against your existing battery before fitting.
- TFDVD7752 fit: The TFDVD7752 uses a two-cell lithium-polymer pack at 7.4V nominal. The AHB772992P-2S connector and cell configuration match the player's battery bay and protection circuit handshake directly.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the bench. The BMS responded correctly to charge termination and did not trigger overcurrent cutoff during disc motor spin-up, which pulls a brief current spike above steady-state draw.
- Temperature during simultaneous charging and playback: Avoid running disc playback while the player is charging. The combined load — disc motor, display backlight, and charging current — raises cell temperature and can cause the thermal protection circuit to throttle output before the pack is depleted.
Why the TFDVD7752 disc stops spinning before the battery indicator reads low
The disc motor draws its highest current at spin-up and during seek operations. As a lithium-polymer cell ages or sits at storage voltage, its internal resistance rises. That resistance causes a short voltage sag during peak current demand — enough to trip the BMS overcurrent threshold even when the reported state of charge looks adequate. A fresh, fully charged pack at 8.4V will sustain spin-up current without triggering that cutoff. If disc stop is the only symptom, charge the replacement pack to full before drawing conclusions about fit.
Screen backlight dimming mid-movie on a new battery
The TFDVD7752 display driver monitors the supply rail and steps down backlight brightness when voltage sags below a set threshold. This happens when the pack is not fully charged or when cell temperature climbs during extended playback. It is not a fault with the battery itself — it is a protective response from the display circuit. Charge the pack fully to 8.4V before use and avoid covering the player's ventilation area during long sessions.