PAP3400 DUO Prestigio MultiPhone Replacement Battery 3.7V 1500mAh

Prestigio MultiPhone 3400 Duo — 3.7V Li-ion Replacement Battery (PAP3400 DUO)

This is a 3.7V, 1500mAh Li-ion cell for the Prestigio MultiPhone 3400 Duo smartphone. It replaces the original PAP3400 DUO battery when the existing cell no longer holds a usable charge across calls, messaging, and app use. Dimensions are 76.00 x 50.00 x 4.02mm — confirm against your existing cell before fitting.

• MultiPhone 3400 Duo fitment: The 3400 Duo runs a dual-SIM modem stack that draws current from both radios simultaneously. This cell matches the voltage rail and physical connector the board expects — no rewiring or adapter needed.
• Bench tested on actual hardware: We cycled this cell through charge and load on the bench. The BMS held cutoff correctly at both ends of the voltage range and did not trip under combined modem and display load.
• Fuel gauge recalibration on first use: 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 to the new cell's actual discharge curve before high-current charging begins on an uncalibrated cell.

Sudden shutdown at 20–30% on the MultiPhone 3400 Duo

This happens when the cell cannot sustain voltage under simultaneous modem and screen load — both SIM radios spike current draw at the same moment and the cell voltage dips below the BMS cutoff threshold before the fuel gauge reads zero. It is a voltage cliff, not a capacity problem. A new cell with a full charge cycle completed will hold voltage through those spikes. If it persists after one full cycle, check that neither SIM slot is forcing a 2G fallback, which increases radio transmit power significantly.

Phone reporting wrong battery percentage after fitting the new cell

The fuel gauge IC on the 3400 Duo stores a learned discharge curve from the old cell in its coulomb counter. When you fit a new cell, that stored curve no longer matches the actual cell chemistry, so the percentage readout drifts — often reading full when the cell is at 70%, or dropping suddenly. Run one complete discharge down to automatic shutdown, then charge uninterrupted to 100% without unplugging early. That single cycle rewrites the fuel gauge reference and the percentage display stabilises.