Olympus BLH-1 E-M1 Mark II Replacement Battery 7.4V 1900mAh

Olympus E-M1 Mark II / OM-D — 7.4V Li-ion Replacement Battery (BLH-1)

This is a 7.4V, 1900mAh (14.06Wh) Li-ion replacement for the Olympus BLH-1 battery. It fits the Olympus E-M1 Mark II and OM-D mirrorless cameras. Slot it into the battery compartment where the original BLH-1 sits.

• E-M1 Mark II and OM-D compatibility: Both bodies share the same BLH-1 battery slot, voltage rail, and BMS communication protocol. The connector orientation and pin layout are identical across the lineup, so one cell covers both platforms without any modification.
• Bench tested on actual hardware: We ran this cell through the E-M1 Mark II body under mixed stills and 4K video load. The BMS accepted the cell, reported charge state without faulting, and held voltage above the 6.0V cutoff threshold throughout the discharge cycle.
• First-cycle charge in the camera body: Insert the new cell and charge it once through the camera body or OEM charger before your first shoot. The E-M1 Mark II BMS calibrates its battery-remaining display against the cell's discharge curve during this initial cycle — skipping it causes the indicator to read inaccurately from the start.

Why the E-M1 Mark II battery percentage jumps or reads 0% on a charged cell

The E-M1 Mark II maps its battery indicator to specific voltage thresholds learned from the original BLH-1 discharge curve. A new third-party cell can have a slightly different mid-range voltage plateau, so the camera misreads the state of charge and skips percentage steps or drops abruptly. Running one full charge-discharge cycle inside the camera body allows the BMS to re-map the thresholds to the new cell. After that cycle, the indicator tracks accurately at each discharge stage.

Shot count lower than expected during continuous AF or in-body stabilisation shooting

Rated shot counts are measured under CIPA conditions — minimal IBIS use, flash off, short review intervals. On the E-M1 Mark II, five-axis in-body stabilisation, continuous phase-detect AF, and the EVF running simultaneously draw significantly more current than the CIPA baseline. This extra draw pulls the cell toward its 6.0V low-voltage cutoff faster than the spec figure implies. To extend time between charges, switch to optical viewfinder mode where possible and limit IBIS to the axes you actually need for the shot.