About this replacement
NEC MobilePro 300E — 3.7V Li-ion Replacement Battery (MIT-BAR01)
This is a 3.7V Li-ion replacement battery rated at 1100mAh (4.07Wh) for the NEC MobilePro 300E handheld PC. It replaces the original MIT-BAR01 cell in units where the factory battery no longer holds a usable charge. The MobilePro 300E runs Windows CE and stores active data in RAM — the main battery is the only power source keeping that memory alive.
- MobilePro 300E compatibility: The 300E uses a single-cell 3.7V Li-ion pack with the MIT-BAR01 part number. This replacement matches that voltage rail and connector geometry, so the BMS handshake completes normally on first insertion.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a MobilePro 300E unit. The BMS accepted the pack without fault codes, and the charge circuit brought it to full voltage without thermal events.
- RAM state before removal: Sync all open files and application data to a host PC before pulling the old battery. The MobilePro 300E holds running application state entirely in volatile RAM — when the main battery drops out, that data is gone with no recovery path.
Why the MobilePro 300E loses saved data during a battery swap
The MobilePro 300E has no onboard flash storage for application state. Open documents, unsaved settings, and active program data live in SRAM that the main battery powers continuously. The moment the cell is removed, that voltage rail drops to zero and the SRAM contents are wiped. Swapping the battery quickly does not help — there is no capacitor or backup cell holding that memory during the swap window.
MobilePro 300E shows black screen and won't boot after new battery installed
A freshly installed Li-ion cell shipped in storage state may sit at 3.0V or below — below the minimum the MobilePro 300E boot sequence requires. The device will show a blank screen or fail to respond to the power button entirely. Connect to the charger for at least 20–30 minutes before pressing power. Once the cell reaches approximately 3.6V, the boot sequence will proceed normally.