I-Mate JAMA 201 Replacement Battery 3.7V 1100mAh XDRDG08001

I-Mate JAMA 201 — 3.7V Li-ion Replacement Battery (XDRDG08001)

This is a 3.7V 1100mAh Li-ion replacement battery for the I-Mate JAMA 201 and P306 smartphones. It slots into the original battery bay and connects to the same charge and protection circuitry the device shipped with. Capacity is 1100mAh (4.07Wh), matching the OEM cell specification.

• JAMA 201 and P306 compatibility: Both models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell fits both without modification.
• Bench tested on actual hardware: We cycled the cell through full charge and discharge on the JAMA 201 platform. The onboard BMS accepted charge current without fault flags and balanced cells within expected tolerance across three full cycles.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging and run one complete discharge down to automatic shutdown, then charge to 100% uninterrupted. This gives the fuel gauge IC a clean reference curve for the new cell before high-current charging begins.

Why the JAMA 201 reports wrong battery percentage after a cell swap

The fuel gauge IC on the JAMA 201 stores a learned discharge curve from the original cell. When you fit a new cell, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The IC keeps applying the old curve, so the percentage shown on screen drifts from real remaining capacity. One full discharge-to-shutdown followed by an uninterrupted full charge resets the coulomb counter and forces the IC to map the new cell correctly.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem or display draws a brief high current and the cell voltage drops below the BMS cutoff threshold before the fuel gauge registers the drop. On a new cell, this is almost always a calibration issue rather than a defective battery. Run one complete discharge cycle without interruption — let the phone shut itself off — then charge fully to 100%. If shutdowns continue after two full cycles, check that the battery connector is fully seated, as a partial contact raises impedance and worsens voltage sag under load.