HTC Typhoon Replacement Battery BTR5600B 3.7V 2200mAh

HTC Typhoon / Tornado Series — 3.7V Li-ion Replacement Battery (BTR5600B)

This is a 3.7V, 2200mAh Li-ion cell (8.14Wh) built to the same electrical spec as the original BTR5600B. It fits the HTC Typhoon, Feeler, Tornado, Robbie, and seven additional models that share the same battery bay and connector. If your device is draining faster than it once did or refusing to hold a charge, the original cell has degraded and this swap restores full capacity.

• Typhoon platform battery sharing: The Typhoon, Tornado, Feeler, and Robbie all run the same 3.7V single-cell architecture with an identical connector pinout and BMS handshake. HTC standardised the battery across this mid-2000s Windows Mobile lineup, so one cell covers the entire group without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the platform, confirmed the BMS accepted the handshake without flagging a fault, and verified the charge IC held voltage within the expected 3.7V nominal range throughout the full cycle.
• Fuel gauge recalibration after install: After fitting this cell, run one complete discharge down to the automatic cutoff, then charge uninterrupted to 100% before resuming normal use. The fuel gauge IC on these Windows Mobile devices was calibrated to the original cell's discharge curve — skipping this step causes the percentage counter to read inaccurately from the first charge.

Sudden shutdown at 20–30% on the replacement cell

This happens because the fuel gauge IC still holds the discharge curve of the old, degraded cell. When the new cell's voltage drops sharply under screen or radio load — a steeper cliff than the worn cell ever produced — the IC misreads remaining capacity and trips a shutdown before the true cutoff. The fix is a full uninterrupted discharge-to-cutoff followed by a full charge. After one complete cycle, the coulomb counter recalibrates against the new curve and the shutdowns stop. If they continue past two full cycles, check that the battery contacts are clean and making firm contact — intermittent resistance causes the same voltage sag.

Device won't power on after sitting in storage with a flat battery

Li-ion cells that self-discharge below approximately 2.5V during storage trigger a BMS lockout — the protection circuit opens to prevent damage and the phone appears completely dead, showing no response to the power button. Connect the device to a charger and leave it untouched for 15–30 minutes before attempting to power on. The charge IC on the Typhoon will trickle current into the cell at a low rate until voltage climbs above the BMS re-enable threshold, at which point normal charging resumes. If the device still shows no charge indicator after 30 minutes, try a different cable — the original micro-USB connectors on these devices are prone to contact wear.