Sonim Armor XP3400 Compatible Battery 3.7V 1750mAh Li-ion

Sonim Armor XP3400 / XP1300 — 3.7V Li-ion Replacement Battery (BAT-01750-01)

This is a 3.7V, 1750mAh Li-ion replacement battery for the Sonim Armor XP3400, XP1300, XP3 Quest, VR-01, and 24 additional Sonim models. It matches the original cell dimensions at 52.00 × 36.00 × 10.30mm. OEM part numbers covered include XP3.20-0001100, XP-0001100, BAT-01750-01 S, and RPBAT-01950-01-S.

• XP3400 and XP1300 platform compatibility: These models share the same 3.7V single-cell architecture, connector pinout, and BMS communication protocol — which is why one cell covers the full lineup without modification or adapter wiring.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the XP3400 platform. The BMS accepted handshake on first connection, charge IC stepped through trickle, CC, and CV phases correctly, and the protection circuit tripped cleanly at the expected over-discharge threshold.
• 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 the new cell's discharge curve before high-current charging begins. Skipping this step is the leading cause of erratic percentage readings and early shutdowns on Sonim devices after a cell swap.

Sudden shutdown at 20–30% on the Sonim XP3400 after a cell swap

This happens because the fuel gauge IC is still calibrated to the old cell's discharge curve. When the modem transmits or the screen peaks, current draw spikes and the new cell's actual voltage drops below the protection threshold — even though the OS is still showing 20–30%. The phone cuts power to protect the cell, not because the cell is faulty. Run one full discharge cycle without fast charging to let the coulomb counter reset against the new cell's real capacity curve.

Phone warm near the battery during the first charge after replacement

A new cell starts with higher internal impedance than a conditioned one. The charge IC pushes current into a cell that hasn't yet settled its internal resistance, and that friction converts to heat. This is normal during the first one or two charge cycles and reduces as the cell's impedance drops. If warmth persists past the third full charge, check that the charge IC is not stuck in fast-charge mode — force a standard 5V/1A charge and monitor from there.