35H00077-02M Dopod D810 Compatible Battery 3.7V 2400mAh

Dopod D810 / CHT9100 — 3.7V Li-Polymer Replacement Battery (35H00077-02M)

This is a 3.7V, 2400mAh Li-Polymer replacement battery for the Dopod D810, CHT9100, and 9100 smartphones. It replaces OEM part numbers 35H00077-02M, 35H00077-00M, and TRIN160. Fit the replacement when the original cell no longer holds adequate charge for calls, messaging, or app use.

• D810 / CHT9100 / 9100 platform fit: All three model numbers share the same battery bay dimensions, connector pinout, and BMS handshake voltage. One cell fits all three without modification.
• Bench tested on actual hardware: We cycled this cell on a D810 unit and confirmed the BMS accepted the charge handshake on the first cycle. Charge IC stepped through the correct CC/CV stages without fault flags.
• Fuel gauge recalibration on first use: On first installation, run one full discharge-charge cycle with fast charging disabled. The fuel gauge IC in the D810 is calibrated to the original cell's discharge curve — giving it one uninterrupted cycle against the new cell lets the coulomb counter reset its reference before higher charge currents are applied.

Sudden shutdown at 20–30% on the Dopod D810

The D810 relies on the fuel gauge IC to estimate remaining charge, but when a degraded or new uncalibrated cell hits a voltage cliff, the device shuts down before the gauge reaches zero. Under modem load or screen-on state, current draw spikes and the cell voltage drops sharply — faster than the fuel gauge expects. The BMS interprets this as an undervoltage condition and cuts power. One full discharge-charge cycle without interruption resets the coulomb counter and brings the shutdown threshold back in line with the new cell's actual discharge curve.

Percentage jumping erratically after cell swap

After fitting a replacement cell, the D810's fuel gauge IC still holds the learned discharge model from the old battery. The result is percentage readings that jump — sometimes skipping 10–15% in either direction — because the stored capacity map no longer matches the new cell. This is not a fault with the replacement cell. Discharge the phone completely until it powers off, then charge uninterrupted to 100% with the screen off. After that single cycle the coulomb counter recalibrates to the new cell and percentage reporting stabilises.