Tiptel AK54 Compatible Battery 3.7V 1050mAh Li-ion

Tiptel Ergophone 6011 — 3.7V Li-ion Replacement Battery (AK54)

This is a 3.7V, 1050mAh Li-ion cell for the Tiptel Ergophone 6010, 6011, and 6020 series mobile phones. It replaces OEM part number AK54 (also cross-referenced as SD474050A). Fit the cell when the original no longer holds a charge or the phone shuts down unexpectedly under load.

• Ergophone 6010 / 6011 / 6020 compatibility: These models share the same battery bay dimensions (53.00 × 33.90 × 5.60mm), the same 3.7V rail, and the same AK54 connector pinout — one cell covers the whole platform without modification.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the Ergophone platform. The BMS accepted the charge handshake cleanly, held voltage above 3.6V through mid-cycle, and triggered the low-voltage cutoff at the expected floor without false trips.
• Fuel gauge recalibration after swap: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before it starts reporting accurate percentages on the status bar.

Sudden shutdown at 20–30% on the Ergophone 6011

This happens when the cell voltage drops below what the modem and display draw can sustain — even though the fuel gauge still shows charge remaining. The original cell's discharge curve was mapped into the coulomb counter over many cycles. A new cell has a slightly different curve, so the OS cuts power before the gauge catches up. One full discharge-charge cycle without interruption resets the reference. After that, the shutdown threshold aligns with the new cell's actual voltage floor.

Battery percentage jumping erratically after fitting the replacement

The fuel gauge IC on the Ergophone 6011 holds a learned model of the old cell's impedance and capacity. Drop in a new cell and that model is stale — the percentage can jump 10–15 points in either direction during the first few charge cycles. This is not a faulty cell. Let the phone discharge to auto-shutoff, then charge uninterrupted to 100%. Repeat once more if the jumps persist — two full cycles are usually enough for the counter to converge on the new cell's actual state of charge.