3M MPro 110 Micro Projector Replacement Battery NK01-S005 3.7V

3M MPro 110 Micro Projector — 3.7V Li-ion Replacement Battery (NK01-S005)

This 3.7V Li-ion battery replaces the original cell in the 3M MPro 110 Micro Projector. It carries a 1050mAh (3.89Wh) capacity and matches the OEM part numbers NK01-S005 and NK03-S005. The MPro 110 is a pocket-sized portable projector used for wireless and mobile presentations.

• MPro 110 compatibility: The MPro 110 uses a compact single-cell Li-ion pack at 3.7V nominal. This replacement matches that voltage rail and physical footprint — 40.40 x 35.45 x 9.45mm — so the cell seats correctly and the BMS handshake with the projector's charge circuit completes without fault.
• Bench tested on actual hardware: We cycled this cell through the MPro 110's internal charger and confirmed the BMS accepted charge without triggering a fault flag. Discharge testing showed the protection circuit cutting off at the correct low-voltage threshold before the projector's lamp-driver rail collapsed.
• Lamp brightness on battery: Set the MPro 110 to eco or low-brightness mode when running on battery. Full lamp brightness draws 30–40% more current than eco mode. In most indoor presentation environments, the difference in projected image quality is negligible, but the current draw on the cell is not.

Why the MPro 110 shuts off before the battery indicator reaches empty

The MPro 110's lamp driver requires a minimum voltage threshold to sustain the lamp arc — typically higher than the cell's absolute BMS cutoff. When the cell voltage sags under load, the lamp-driver rail drops below that threshold before the battery indicator registers empty. The projector shuts off not because the battery is fully depleted, but because the lamp can no longer maintain output at that voltage level. A degraded or deeply cycled cell will sag earlier under the same load, making this cutoff happen sooner in the discharge cycle.

MPro 110 showing a charging indicator but battery not gaining capacity

The MPro 110 uses an internal charger that checks cell voltage before entering CC phase. If the replacement cell arrives at a very low resting voltage — below roughly 2.5V — the charger may not initiate a full charge cycle and the indicator can appear active without real current flowing into the cell. Connect the projector to USB power and leave it for 30 minutes before checking whether the cell voltage has risen above 3.0V. If it has not budged, the cell needs a trickle pre-charge from an external Li-ion charger set to recovery mode before the internal charger will take over normally.