About this replacement
Olympus OM SYSTEM OM-1 — 7.2V Li-ion Replacement Battery (BLX-1)
This 7.2V, 1600mAh Li-ion battery is a direct cell replacement for the Olympus OM SYSTEM OM-1 and OM-1 Mirrorless cameras. It powers the sensor, autofocus system, and image processing stack through the same voltage rail as the OEM BLX-1. Capacity is rated at 11.52Wh.
- OM SYSTEM OM-1 and OM-1 Mirrorless compatibility: Both bodies share the same BLX-1 battery bay, connector pinout, and BMS communication protocol — one cell fits either body without modification.
- Bench tested on actual hardware: We cycled this cell through the OM-1 body charger and verified BMS handshake, charge acceptance, and discharge curve across the full capacity range. The BMS logged no rejection flags during testing.
- First-install charge cycle on the OM-1: Seat the new cell in the camera body and run one full charge cycle through the body's USB-C port or OEM charger before shooting. The OM-1 BMS maps battery-remaining percentage to the cell's discharge curve during this first cycle — skipping it causes erratic percentage readings on the top-plate LCD.
Why the OM-1 draws harder than the rated capacity suggests
The OM-1 runs simultaneous loads that most camera bodies don't stack at once — in-body 5-axis stabilisation, stacked sensor readout, phase-detect AF, and the electronic viewfinder all draw current in parallel. Under Starry Sky AF or Pro Capture mode, those loads compound further. A 1600mAh cell rated at camera spec accounts for standard shooting, not sustained multi-system operation. If shot count falls short of expectation, check which drive modes and processing features are active — turning off the EVF in favour of the rear screen alone reduces draw noticeably.
Battery percentage jumping or resetting to 100% mid-shoot
This happens when the OM-1 BMS hasn't yet mapped its voltage thresholds to the replacement cell's discharge curve. The camera ships calibrated to the OEM cell's specific voltage-to-capacity profile, and a new third-party cell needs one full charge-discharge cycle before that mapping aligns. Until it does, the indicator reads off an incorrect lookup table and jumps between percentage steps unevenly. Run one full cycle from 0% to 100% through the camera body — percentage display stabilises after that cycle completes.