Ulefone Paris 3.7V 1800mAh Compatible Battery 29-11900-000-00

Ulefone Paris / U007 — 3.7V Li-ion Replacement Battery (29-11900-000-00)

This is a 3.7V, 1800mAh Li-ion cell that replaces the original battery in the Ulefone Paris and U007 smartphones. It carries OEM part number 29-11900-000-00 and matches the original's 81.00 × 57.50 × 4.00mm footprint exactly. Fit it when the original cell no longer holds a charge through a normal day of use.

• Paris and U007 compatibility: Both models share the same battery bay dimensions, connector pinout, and 3.7V nominal voltage rail, so one cell covers both. The BMS handshake is identical across the two variants — no firmware differences affect charging behaviour.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on a Paris unit. The BMS accepted charge without tripping, held the voltage rail steady under screen-on and modem-active load, and logged no anomalous cutoff events during the test sequence.
• Fuel gauge recalibration after swap: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard current. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging begins on an uncalibrated reference.

Why the Paris reports wrong battery percentage after a cell swap

The Paris uses a coulomb-counting fuel gauge IC that builds its percentage model against the original cell's discharge curve. When you install a new cell, the IC still references its stored curve — which no longer matches. The mismatch shows up as percentage jumps, early low-battery warnings, or a reading that stalls at one number for a long stretch. One full discharge-charge cycle at standard current resets the coulomb counter and lets the IC build a fresh curve against the new cell.

Sudden shutdown at 20–30% remaining on the replacement cell

This is a voltage cliff issue, not a capacity problem. When the modem transmits or the screen hits full brightness, current draw spikes briefly. If the fuel gauge IC is still calibrated to the old cell, it can misread the actual state of charge — the reported percentage looks healthy while the real cell voltage has already dropped near the BMS cutoff threshold. The BMS trips and the phone shuts off without warning. Run one full cycle first, then check whether the phone holds voltage above 3.5V under load before dismissing the issue.