HTC Wildfire BA S390 Replacement Battery 3.7V 2200mAh

HTC Wildfire / A3333 — 3.7V Li-ion Replacement Battery (BA S390 / RHOD160)

This is a 3.7V, 2200mAh Li-ion cell for the HTC Wildfire (A3333), also known as the Bee and Wildfire 6225. It replaces OEM part numbers BA S390, BA S420, RHOD160, 35H00123-00M, and related variants. If your original cell no longer holds a charge through a normal day, this cell slots directly into the same bay.

• Wildfire / A3333 platform fit: These models share the same battery bay dimensions (65.00 × 43.28mm), connector pinout, and BMS handshake protocol. The BA S390 and RHOD160 cross-reference to the same physical cell, so one SKU covers the full Wildfire lineup listed above.
• Bench tested on actual hardware: We ran this cell on a Wildfire A3333 unit and confirmed the BMS accepted charge handshake on first connection, voltage held stable at 3.7V nominal under screen-on load, and charge IC reached full cutoff without tripping protection.
• Fuel gauge recalibration on first use: After installation, run one full discharge to auto-shutoff, then charge uninterrupted to 100% before normal use. The Wildfire's fuel gauge IC calibrates its coulomb counter against this first cycle — skipping it causes the percentage display to read inaccurately for weeks.

Why the Wildfire reports wrong battery percentage after a cell swap

The Wildfire uses a fuel gauge IC that builds its charge model around the discharge curve of the original cell. When you install a new cell, the IC is still referencing the old, degraded curve — so reported percentage drifts from actual state of charge. The fix is a full discharge-charge cycle with the screen on and mobile data active, which forces the coulomb counter to resample the new cell's actual voltage profile. After one complete cycle, percentage reporting stabilises. If it still jumps after two cycles, the gauge IC may need a battery stats wipe via recovery.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under modem or display load — a voltage cliff the fuel gauge did not predict because the calibration cycle was skipped. Under peak draw, the cell briefly dips below the BMS cutoff threshold (typically 3.0V), which triggers an immediate shutdown even though the percentage display still showed charge remaining. Run the recalibration cycle described above first. If shutdowns persist after two full cycles, check that the battery connector pins are fully seated — a high-resistance contact at the connector causes the same voltage sag symptom under load.