Motorola JW50 Moto Module 5G Compatible Battery 3.85V 1900mAh

Motorola Moto Module 5G (JW50) — 3.85V Li-Polymer Replacement Battery

The JW50 is a 3.85V, 1900mAh Li-Polymer cell that powers the Motorola Moto Module 5G, MD1005G, and QTM052. It slots into the same physical envelope as the factory cell at 88.50 × 50.20 × 2.80mm. Swap it when the original cell no longer holds voltage under 5G modem or display load.

• Moto Module 5G, MD1005G, QTM052 compatibility: All three identifiers reference the same hardware platform. They share an identical battery footprint, connector pinout, and BMS handshake protocol — one cell fits all three without modification.
• Bench tested on actual hardware: We cycled the JW50 through charge and discharge on the Moto Module 5G platform. The BMS accepted the cell, protection thresholds triggered correctly at cutoff, and the fuel gauge IC completed its initialisation pass without error flags.
• Fuel gauge recalibration on first use: Disable fast charging for the first full discharge-charge cycle after fitting this cell. The fuel gauge IC is calibrated to the old cell's discharge curve. Running one slow cycle first lets the coulomb counter remap against the new cell before high-current charging is applied to an uncalibrated state.

Sudden shutdown at 20–30% on the Moto Module 5G

This is a voltage cliff, not a capacity problem. The 5G modem draws a short, high-current spike during handoff events, and a degraded or freshly swapped cell can drop below the BMS cutoff voltage under that load even when the reported state of charge reads 20–30%. The fuel gauge IC does not see the sag fast enough to warn the OS before shutdown occurs. After fitting a new cell, run two full discharge-charge cycles to let the coulomb counter learn the actual discharge curve — the false shutdowns typically stop once the gauge is tracking real cell voltage.

USB-PD fast charge not negotiating on the first cycle after fitting

The Moto Module 5G fast charge protocol requires the BMS to report a valid cell state before the charge IC opens the high-current path. On a new cell that has not completed one full cycle, the BMS may not pass the handshake, and the charger falls back to standard 5W input. This is not a fault in the cell or the charger. Charge the device once at standard speed to a full 100%, discharge to below 20%, then charge again — fast charge negotiation typically resumes on the second cycle once the BMS has a baseline reference for the cell.