BlackBerry Curve 9360 EM1 Replacement Battery 3.7V 1600mAh

BlackBerry Curve 9360 — 3.7V Li-ion Replacement Battery (EM1)

This is a 3.7V, 1600mAh Li-ion replacement battery for the BlackBerry Curve 9360 smartphone. It uses the OEM part number EM1 and fits directly into the standard battery bay. The cell measures 42.00 × 39.20 × 10.50mm — the same footprint as the original.

• Curve 9360 fitment: The EM1 battery platform covers the Curve 9360's voltage rail and connector pinout. The BMS handshake matches the phone's charge IC, so the device recognises the cell and accepts charge without triggering a battery error.
• Bench tested on actual hardware: We cycled this battery through discharge and charge on the Curve 9360. The BMS held cutoff correctly at both ends, and the phone's fuel gauge picked up the cell without resetting mid-cycle.
• Fuel gauge recalibration on first use: After installing this cell, run one complete discharge down to auto-shutdown, then charge uninterrupted to 100% before resuming normal use. The Curve 9360's fuel gauge IC was calibrated to your old cell's discharge curve — skipping this step causes the percentage to read inaccurately from day one.

Why the Curve 9360 reports the wrong battery percentage after a cell swap

The Curve 9360 uses a coulomb-counter fuel gauge IC that builds a discharge model over time. When a new cell goes in, that model still reflects the old cell's internal resistance and voltage curve. The gauge reads state-of-charge against the wrong reference, so it can show 40% when the phone is actually near cutoff. One full uninterrupted discharge-charge cycle forces the IC to re-map against the new cell's actual curve. After that cycle, percentage readings stabilise.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under load — typically during radio transmission or screen-on bursts — faster than the fuel gauge expects. The phone's protection circuit cuts power before the displayed percentage reaches zero because actual cell voltage has already fallen below the 3.0V cutoff threshold. The fuel gauge IC hasn't yet learned this cell's voltage-sag profile under modem load. Run two full discharge-charge cycles and the shutdowns should stop as the gauge recalibrates its low-voltage cliff detection to 3.0V.