About this replacement
Olympus OM SYSTEM OM-1 — 7.2V Li-ion Replacement Battery (BLX-1)
This is a 7.2V, 2050mAh Li-ion replacement for the BLX-1 battery used in the OM SYSTEM OM-1 mirrorless camera. It fits both the OM SYSTEM OM-1 and OM-1 Mirrorless body variants. Same voltage, same form factor, same connector orientation as the original cell.
- OM-1 body compatibility: The OM SYSTEM OM-1 runs a single BLX-1 cell at 7.2V. Both listed body variants share the same battery bay dimensions and pin layout — 54.70 x 39.20 x 20.90mm — so one part number covers both. The BMS communicates over the same three-contact interface as the OEM cell.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the OM-1 body. The BMS accepted the cell without rejection flags, reported charge state correctly after one full charge cycle, and held stable voltage under sustained continuous burst shooting.
- First charge in the camera body: Charge this battery inside the OM-1 body via USB-C before first use — not in a third-party charger. The OM-1 BMS maps the battery percentage display during a full in-body charge cycle. Skipping this step can cause the indicator to show inaccurate remaining charge from the start.
Why the OM-1 draws harder than its shot count suggests
The OM-1 stacks several high-draw systems simultaneously — the Quad Bayer stacked sensor, computational processing for subject detection AF, in-body 5-axis stabilisation, and the EVF backlight. Each adds current draw beyond what a single-shot frame count captures. Video recording compounds this further because the processor, sensor, and IBIS all run continuously rather than in short bursts. A 2050mAh cell rated at a specific shot count assumes CIPA test conditions, which don't reflect real mixed-use shooting with AF Tracking and Pro Capture enabled.
Battery percentage jumping or freezing on the OM-1 display
This happens when the BMS has not completed a full in-body calibration cycle with the new cell. The camera maps its percentage indicator to voltage thresholds it learned from the previous cell's discharge curve. A new cell with a slightly different curve at mid-charge voltages — typically between 7.6V and 7.0V — causes the indicator to skip steps or stall. Fix this by running one complete charge-to-full, then shoot until the camera shuts down at low battery, then charge to full again inside the camera body. After that cycle, the percentage display stabilises.