Sonim XP3 Quest Replacement Battery 3.7V 1100mAh

Sonim XP3 Quest / XP1 Series — 3.7V Li-ion Replacement Battery (XP1-0001100)

This is a 3.7V, 1100mAh Li-ion battery for the Sonim XP3 Quest, XP1, and XP1 BT rugged smartphones. It matches OEM part number XP1-0001100 and fits directly into the original battery bay. If your XP3 Quest is shutting down unexpectedly or no longer holding a charge, this cell replaces the original.

• XP3 Quest, XP1, and XP1 BT fit: All three models share the same battery footprint, connector pinout, and BMS handshake protocol. The cell dimensions — 55.11 × 35.55 × 5.77mm — match the original bay exactly, so no modification is needed.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the XP3 Quest platform. The BMS accepted the cell without fault codes, and the charge IC stepped through trickle, constant-current, and constant-voltage phases correctly.
• 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 what causes erratic percentage readings in the first week.

Sudden shutdown at 20–30% on the XP3 Quest after a cell swap

The XP3 Quest's fuel gauge IC holds a discharge model calibrated to the original cell. A new cell with a slightly different internal resistance profile hits its voltage floor at a different state-of-charge point than the old model predicts. Under modem or screen load — both high-draw events — the cell voltage sags below the BMS cutoff before the gauge reaches 0%. The phone reads 25% and powers off hard. One full discharge cycle without fast charging allows the coulomb counter to resync to the new cell's actual voltage curve. After that cycle, the shutdowns stop.

Phone warm near the battery during the first few charges

A new Li-ion cell starts with higher internal impedance than a broken-in cell. The charge IC pushes the same current it used on the old cell, but the higher resistance generates more heat in the new one. This is normal for the first three to five charge cycles as the cell's internal structure settles. Keep the phone out of cases during those first charges to let heat dissipate. By cycle five, impedance drops and the warmth resolves. If the phone stays hot beyond that point, check that the charge IC has not locked into a higher-current fast-charge profile — drop to standard 5V charging until the cell is fully broken in.