HTC 7 Trophy Replacement Battery 3.7V 2200mAh 35H00134-17M

HTC 7 Trophy / Spark / T8686 — 3.7V Li-ion Replacement Battery (35H00134-17M)

This is a 3.7V, 2200mAh Li-ion cell built to the same OEM spec as part number 35H00134-17M. It fits the HTC 7 Trophy, Spark, and T8686 smartphones. Swap it in when the original cell can no longer hold a charge or the phone shuts down unexpectedly under load.

• 7 Trophy, Spark, and T8686 compatibility: These three models share the same battery bay dimensions, connector pin-out, and BMS handshake protocol — all running off a 3.7V nominal rail. One cell covers all three without any hardware modification.
• Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on a T8686 unit. The BMS accepted the cell on first insertion, charge IC engaged normally, and the fuel gauge IC tracked state-of-charge without requiring a manual reset cycle.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell.

Why the HTC 7 Trophy reports wrong battery percentage after a cell swap

The HTC 7 Trophy uses a coulomb counter inside the fuel gauge IC to estimate remaining charge. When you replace the cell, the IC still holds calibration data mapped to the old cell's discharge curve. The new cell has a different internal resistance profile, so the reported percentage drifts from actual charge state. One full discharge to auto-shutoff followed by a complete charge to 100% resets the coulomb counter against the new cell.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage cliff issue, not a capacity problem. When the modem or display draws a heavy current burst, the cell's terminal voltage drops sharply below the BMS protection threshold — even if the reported percentage looks healthy. The phone interprets the voltage dip as a dead cell and cuts power. To confirm this is the cause, check whether shutdowns happen during calls, video playback, or screen-on navigation rather than during idle. If so, let the cell complete two full recalibration cycles; if the problem persists, verify the battery bay contacts are clean and making firm contact at 3.7V nominal.