Samsung SCH-i920 Replacement Battery AB944757GZ 3.7V 3200mAh

Samsung SCH-i920 Omnia II — 3.7V Li-ion Replacement Battery (AB944757GZ)

This is a 3.7V, 3200mAh Li-ion cell built to the AB944757GZ specification. It fits the Samsung SCH-i920, SCH-i920V, and SCH-i920 Omnia II. When the original cell can no longer hold a stable charge through a normal day, this battery replaces it directly.

• SCH-i920 and SCH-i920V platform fit: Both handsets share the same battery bay dimensions, connector pinout, and BMS communication protocol. The AB944757GZ part number covers both variants — one cell, same voltage rail, same BMS handshake across the platform.
• Bench tested on actual hardware: We ran the cell through charge and discharge cycles on an SCH-i920 test unit. The BMS accepted charge from the onboard charge IC without triggering a protection cutoff. Voltage held steady across the discharge curve under screen and modem load.
• Fuel gauge recalibration on first use: On first installation, disable fast charging and run one full discharge-charge cycle at standard current. This lets the fuel gauge IC build an accurate discharge curve for the new cell before high-current charging begins on an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the SCH-i920 after a cell swap

This happens because the Omnia II's fuel gauge IC still holds the discharge curve of the old, degraded cell. The new cell has a steeper voltage cliff under modem or display load than the IC expects. When real cell voltage drops below roughly 3.5V under load, the phone cuts out — even though the reported percentage reads 20–30%. One full discharge-charge cycle forces the coulomb counter to remap against the new cell's actual curve. After that recalibration cycle, the shutdowns stop.

Phone warm near the battery compartment during the first charge

A new high-capacity cell has lower internal impedance than the worn cell it replaced. The SCH-i920's charge IC pushes current at a rate calibrated against the older cell's resistance, which causes slightly elevated heat at the battery contact area on the first charge. This is normal and resolves after the first full cycle as the charge IC adapts. If the case becomes hot to the touch — not just warm — remove the battery and check that the contacts are seated flat against the terminal pads before recharging.