Samsung SCH-A310 Replacement Battery BST1019SE 3.7V 1000mAh

Samsung SCH-A310 — 3.7V Li-ion Replacement Battery (BST1019SE)

This is a 3.7V, 1000mAh Li-ion battery that replaces the original BST1019SE in the Samsung SCH-A310 mobile phone. It restores power to the device for calls, messaging, and basic applications. Voltage and capacity match the original specification exactly.

• SCH-A310 fit: The SCH-A310 uses the BST1019SE footprint — a compact Li-ion cell with a specific connector pitch and BMS handshake tied to that voltage rail. This replacement matches that configuration so the phone's charge IC recognises the battery and initiates the correct charge curve.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the SCH-A310 platform. The BMS negotiated correctly with the phone's charge IC, accepted a full charge without interruption, and held voltage within the expected window across the discharge curve.
• Fuel gauge recalibration on first use: After installing this battery, run one complete discharge down to automatic shutdown, then charge uninterrupted to 100% before using the phone normally. This gives the fuel gauge IC a full reference cycle against the new cell's discharge curve — without it, percentage readings will be inaccurate from the start.

Why the SCH-A310 reports wrong battery percentage after a cell swap

The SCH-A310's fuel gauge IC builds its percentage model from the discharge curve of the cell it last calibrated against. When a new cell goes in, that stored curve no longer matches the actual cell chemistry in the phone. The gauge keeps using old reference data, so it reports percentages that are consistently off — either higher or lower than reality. One full discharge-to-shutdown followed by an uninterrupted charge to 100% resets the calibration and aligns the gauge to the new cell.

Sudden shutdown at 20–30% on the replacement battery

This happens when the cell voltage drops sharply under load — typically during a call when the modem draws a surge of current. At that point, the voltage falls below the BMS cutoff threshold even though the gauge still shows charge remaining. The fuel gauge IC reads a stored state-of-charge figure, not real-time voltage, so it doesn't predict the drop. If this occurs, run one full calibration cycle as described above; if shutdowns continue past that, check that the battery contacts on the phone are clean and making firm contact, and confirm resting voltage reads above 3.6V with a multimeter before reinstalling.