HTC Desire 650 4G B2PZ4100 Compatible Battery 3.85V 2940mAh

HTC Desire 650 4G — 3.85V Li-Polymer Replacement Battery (B2PZ4100)

This 3.85V, 2940mAh Li-Polymer cell replaces the original battery in the HTC Desire 650 4G (model 99HALL015-00). It matches the OEM dimensions of 77.36 × 58.25 × 3.88mm and uses OEM part references B2PZ4100 and 35H00267-01M. Swap it in when the original cell no longer holds charge, shuts down unexpectedly, or swells.

• Desire 650 4G fit: The Desire 650 4G uses a fixed 3.85V cell with a dedicated BMS connector that communicates state-of-charge to the phone's fuel gauge IC. This replacement carries the same connector pinout and BMS handshake, so the charge IC recognises the cell and negotiates current correctly.
• Bench tested on actual hardware: We ran this cell through a full charge and load cycle on a Desire 650 4G unit. The BMS handed off cleanly to the phone's charge IC, held steady voltage under screen and modem load, and hit the rated 2940mAh within normal tolerance.
• Fuel gauge recalibration after install: On first use after fitting, disable fast charging and run one complete discharge-to-charge cycle. This lets the phone's fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell — preventing erratic percentage readings from the first day.

Sudden shutdown at 20–30% on the Desire 650 4G after a cell swap

The Desire 650 4G's fuel gauge IC stores a discharge curve learned from the original cell. When a new cell goes in, the stored curve no longer matches the actual voltage-versus-capacity relationship. Under modem or display load, the phone hits a voltage cliff — real cell voltage drops below the shutdown threshold while the gauge still reports 20–30%. The fix is one full uninterrupted discharge down to auto-shutoff, then a complete charge to 100% with fast charging disabled. After that single cycle the coulomb counter resets and the shutdowns stop.

USB fast charge not accepted on the first cycle after replacement

The Desire 650 4G's charge IC runs a handshake with the battery BMS before stepping up to fast-charge current. On a freshly installed cell with no charge history, the BMS may respond conservatively and the phone falls back to standard 5V charging. This is normal on cycle one. Complete the first full charge at standard rate — the BMS logs the session, and fast charging negotiation succeeds from the second cycle onward. If fast charge still does not engage after two full cycles, check that the USB cable supports the required current rating.