Motorola EDGE 40 NEO Compatible Battery 3.91V 4850mAh

Motorola Edge 40 Neo (XT2307) — 3.91V Li-Polymer Replacement Battery (SB18D87942)

This 3.91V, 4850mAh lithium-polymer cell replaces the original battery in the Motorola Edge 40 Neo (XT2307-1, XT2307-2, XT2307-3). It matches the OEM form factor at 86.70 × 63.30 × 5.20mm, so it fits the chassis without modification. Capacity figure is 18.96Wh as sourced from product specifications.

• XT2307 variant coverage: The XT2307-1, -2, and -3 share the same physical cell bay, connector pinout, and BMS handshake protocol — one cell fits all three regional variants without any wiring or adapter changes.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an XT2307 unit. The BMS accepted the cell without error flags, and the charge IC transitioned correctly through trickle, CC, and CV phases.
• First-cycle fast charge tip: On first use after installation, disable fast charging for one full discharge-charge cycle. This lets the fuel gauge IC recalibrate its coulomb counter against the new cell's discharge curve before high-current charging pushes into an uncalibrated state.

Sudden shutdown at 20–30% on the Edge 40 Neo after a cell swap

The fuel gauge IC on the XT2307 uses a coulomb counter that was calibrated to the old cell's internal resistance profile. When a new cell goes in, the counter still references the old discharge curve, so the reported percentage drifts from actual cell voltage. Under modem or display load, the new cell's voltage can drop below the hardware cutoff threshold before the gauge reads zero — causing an unexpected shutdown. One complete discharge-to-shutdown followed by a full charge cycle forces the IC to remap the curve to the new cell. After that cycle, shutdowns at partial charge should stop.

USB-PD fast charging not activating after battery replacement

On the first charge cycle after a cell swap, the Edge 40 Neo's charge IC sometimes holds the new cell in trickle or standard charge mode while it validates BMS handshake data from the replacement cell. This is not a fault — it is the IC running a safety check before committing to high-current delivery. If fast charging still does not engage after the first full cycle, check that the charger output is confirmed at 5V/3A or 9V/2A using a USB meter. A charger that cannot hold those rails cleanly will fall back to standard charge regardless of the cell installed.