HTC Desire 300 Replacement Battery BP6A100 3.8V 1650mAh

HTC Desire 300 Series — 3.8V Li-ion Replacement Battery (BP6A100)

This is a 3.8V, 1650mAh Li-ion replacement battery for the HTC Desire 300, 301, 301e, and Z3 smartphones. It replaces OEM part numbers BP6A100 and 35H00190-09M. If your Desire 300 shuts down unexpectedly, no longer holds charge, or won't power on, this is the cell to replace.

• Desire 300 / 301 / 301e / Z3 platform fit: These models share the same battery bay dimensions, connector pinout, and charge IC handshake. One cell covers all four variants without modification.
• Bench tested on actual hardware: We ran this cell through a full charge cycle on a Desire 300 unit. The BMS accepted the charge protocol correctly, the fuel gauge IC registered the new cell, and charge termination triggered at the expected cutoff voltage.
• Fuel gauge recalibration on first use: After fitting this battery, run one complete discharge down to auto-shutdown, then charge uninterrupted to 100% before normal use. This lets the coulomb counter recalibrate against the new cell's discharge curve — skipping it causes the OS to report inaccurate percentages for several days.

Sudden shutdown at 20–30% on the Desire 300 after a cell swap

This happens because the fuel gauge IC is still using the old cell's discharge curve to estimate remaining capacity. The new cell hits a voltage cliff under display or modem load before the OS thinks it's near empty. The phone cuts out to protect the cell even though the percentage shown looked safe. One full discharge-to-shutdown followed by a complete uninterrupted charge forces the coulomb counter to map the actual curve — after that cycle, reported percentage tracks correctly.

Device won't power on after the replacement battery sat in storage

Li-ion cells self-discharge in storage. If the cell voltage dropped below approximately 2.5V, the BMS enters a lockout state and blocks normal charging to prevent charging a damaged cell. Plugging into a standard charger appears to do nothing. Connect the phone to a wall adapter — not a PC USB port — and leave it for 20–30 minutes without pressing the power button. The charge IC will trickle current into the cell until it recovers above the BMS re-enable threshold, typically around 3.0V, after which normal charging resumes.