ALBA ACSE2G Compatible Battery 3.7V 1200mAh Li-ion

ALBA ACSE2G — 3.7V Li-ion Replacement Battery

This is a 3.7V 1200mAh Li-ion cell for the ALBA ACSE2G smartphone. It slots directly into the ACSE2G handset and restores calling, messaging, and app functionality lost to a degraded original cell. No OEM part number exists for this unit — the ACSE2G and cell dimensions (53.00 × 33.90 × 5.70mm) are the fit references.

• ACSE2G cell fit: The ACSE2G uses a compact 3.7V single-cell architecture with a low-current BMS matched to the phone's charge IC. Any replacement cell must match the connector pinout and physical envelope — this cell does both.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a 3.7V single-cell rig, confirmed BMS communication with the charge IC, and verified the protection circuit tripped correctly at low-voltage cutoff without locking the device out.
• First-cycle recalibration on the ACSE2G: On first use after installation, disable fast charging if your charger supports it and run one full discharge down to auto-off, then charge uninterrupted to 100%. The ACSE2G's fuel gauge IC was calibrated to the old cell's discharge curve — one complete cycle rewrites that reference against the new cell.

Sudden shutdown at 20–30% on the ACSE2G after a cell swap

The ACSE2G's fuel gauge IC holds a learned discharge curve from the old cell. When a new cell goes in, the IC still references the old curve and misjudges the voltage cliff — the point where cell voltage drops sharply under modem or screen load. The phone reads 25% but the cell voltage has already fallen below what the SoC needs to stay on. One full discharge-to-cutoff and uninterrupted recharge resets the coulomb counter and resolves this.

ACSE2G not powering on after the replacement cell sat in storage

Li-ion cells self-discharge in storage, and if this one dropped below roughly 2.5V per cell, the BMS will have locked out to prevent damage — the phone won't respond to the power button or show a charge indicator. Connect the phone to a wall adapter, not a PC port, and leave it for 15–20 minutes without pressing anything. The charge IC will push a trickle current to bring the cell above the BMS re-enable threshold, typically around 2.9V, after which the device will boot normally.