Samsung Galaxy A9 EB-BA900ABE Replacement Battery 3.85V 4000mAh

Samsung Galaxy A9 2016 — 3.85V Li-Polymer Replacement Battery (EB-BA900ABE)

This is a 3.85V, 4000mAh Li-Polymer replacement battery for the Samsung Galaxy A9 and Galaxy A9 2016 series, including the Duos TD-LTE and SM-A9000 variants. It replaces part number EB-BA900ABE when the original cell can no longer hold adequate charge through a full day of use. Capacity figures are taken directly from product data — 15.4Wh total energy.

• Galaxy A9 2016 series compatibility: The SM-A9000, A9 2016 standard, and Duos TD-LTE models all share the same battery bay geometry, connector pinout, and BMS handshake protocol — one cell fits the entire production run without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the SM-A9000 platform. The BMS communicated correctly with Samsung's charge IC, accepted current without fault codes, and held voltage within spec across the full state-of-charge range.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge down to automatic shutdown, then charge uninterrupted to 100%. This gives the coulomb counter a clean reference cycle against the new cell's actual discharge curve before adaptive charging routines take over.

Why the Galaxy A9 reports wrong battery percentage after a cell swap

Samsung's fuel gauge IC builds a discharge model from hundreds of charge cycles on the original cell. When you install a new cell, that stored model no longer matches the actual voltage-to-capacity curve of the fresh battery. The IC keeps reading state of charge against the old curve, so the percentage shown on screen can be off by 10–20% in either direction. One full uninterrupted discharge-to-shutdown followed by a complete charge resets the coulomb counter and forces the IC to map the new cell from scratch.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage cliff — not a capacity fault. Under peak load from the modem, GPS, or screen at full brightness, the cell's internal resistance causes voltage to sag below the BMS cutoff threshold even though the reported percentage still looks adequate. It happens most often on a freshly installed cell before the fuel gauge has recalibrated. Run the recalibration cycle first. If shutdowns persist after one full cycle, check that the battery connector is fully seated — a partial connection raises contact resistance and worsens sag under load, typically triggering cutoff at 3.2V or below.