Lenovo BL233 A3600-D Replacement Battery 3.7V 1350mAh

Lenovo A3600-D Series — 3.7V Li-ion Replacement Battery (BL233)

The BL233 is a 3.7V, 1350mAh Li-ion cell that fits the Lenovo A3600-D, A3800-D, A2800-D, and A1000-A smartphones. It replaces a worn or failed original battery that no longer holds charge under normal use. Capacity figures come from the product data — 5Wh at 3.7V nominal.

• A3600-D, A3800-D, A2800-D, A1000-A compatibility: These four models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The BL233 footprint is 56.00 × 48.90 × 5.20mm — verified against each chassis before listing.
• Bench tested on actual hardware: We ran the BL233 through charge and discharge cycles on a Lenovo A3600-D unit. The BMS accepted the cell without rejection flags, and the charge IC cycled through CC/CV phases cleanly with no cutoff errors.
• Fuel gauge recalibration on first install: On first use after installation, disable fast charging and run one full discharge-to-charge cycle. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current charging begins on an uncalibrated cell.

Why the A3600-D reports the wrong battery percentage after a cell swap

The fuel gauge IC stores a discharge curve calibrated to the original cell. When a new cell goes in, the IC has no reference data for the new cell's internal resistance or voltage response. The percentage display pulls from stale curve data until the IC relearns. One full discharge from 100% down to automatic shutdown, followed by an uninterrupted charge to 100%, forces the coulomb counter to reset against the new cell.

Sudden shutdown at 20–30% on the replacement BL233

This happens when the cell voltage drops below the BMS cutoff threshold under load — modem radio and screen backlight together can pull enough current to cause a voltage sag the IC reads as critically low. The fuel gauge IC sees a cliff in the discharge curve and trips the BMS before the displayed percentage reaches zero. Run the first calibration cycle without heavy app use to give the IC accurate low-voltage reference data. After calibration, sudden shutdowns at 20–30% should stop; if they persist, check that the cell connector is fully seated — a partial contact raises effective impedance and worsens voltage sag.