Emporia AK-V27 Simplicity Replacement Battery 3.7V 1050mAh

Emporia Simplicity V27 — 3.7V Li-ion Replacement Battery (AK-V27)

This 3.7V, 1050mAh Li-ion battery replaces the original AK-V27 cell in the Emporia Simplicity (V27) mobile phone. It fits directly into the battery compartment and connects to the same charge IC and fuel gauge circuit as the factory unit. Capacity matches the OEM specification at 1050mAh (3.89Wh).

• Simplicity V27 fitment: The V27 uses a compact 66.45 × 42.13 × 4.05mm cell tied to a fuel gauge IC that reads cell impedance on each charge cycle. A physically mismatched or wrong-voltage cell triggers charge IC errors — this cell matches the OEM dimensions and voltage rail exactly.
• Bench tested on actual hardware: We ran this cell through a full charge cycle on the V27 charge IC and monitored BMS handshake, charge acceptance, and cutoff voltage. The cell accepted charge without error flags and reached full cutoff voltage within expected parameters.
• First-cycle fuel gauge recalibration: After fitting this cell, disable any fast-charge mode and run one complete discharge-to-charge cycle before normal use. This lets the fuel gauge IC map the new cell's discharge curve before locking in percentage readings — skipping this step causes erratic percentage jumps for the first several cycles.

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

This happens because the fuel gauge IC is still calibrated to the old cell's discharge curve. When the phone hits a load spike — screen backlight, a call connecting, or a network search — the new cell's voltage drops below what the IC expects at that state of charge. The phone interprets the sag as a critical low-voltage event and shuts down even though the cell still has usable capacity. Run one full discharge to the automatic power-off point, then charge uninterrupted to 100% — this forces the coulomb counter to reset against the real cell curve.

Phone warm near the battery during the first few charges after replacement

A new Li-ion cell has higher internal impedance than a broken-in cell. The charge IC pushes current into this higher-impedance load, and the additional resistive heating is normal for the first three to five cycles. If the phone feels uncomfortably hot or charging stops early, check that no fast-charge adapter is in use — the V27 charge IC is rated for standard 5V input. Warmth should reduce noticeably after the cell's impedance settles, typically by the third full cycle.