Olympus BLS-1 Evolt E-450 Replacement Battery 7.4V 1150mAh

Olympus Evolt E-450 / E-410 / E-620 — 7.4V Li-ion Replacement Battery (BLS-1)

This is a 7.4V, 1150mAh Li-ion cell built to fit the Olympus BLS-1 slot. It covers the Evolt E-400, E-410, E-450, and E-620 bodies, plus additional Olympus models sharing the same battery bay. Voltage and form factor match the OEM spec exactly.

• Evolt E-400 through E-620 compatibility: These four Evolt bodies share the same BLS-1 bay dimensions, 7.4V supply rail, and contact pin layout. The BMS in each body reads the same charge curve, so one cell covers the full group without modification.
• Bench tested on actual hardware: We cycled this cell through the Evolt E-450 body using the OEM charger. The BMS accepted the cell, battery-remaining display tracked consistently, and the autofocus and LCD draw held stable across charge and discharge cycles.
• First-use charge cycle on E-series bodies: Insert this cell and run one complete charge cycle through the camera body or OEM charger before heavy shooting. The E-series BMS calibrates the battery-remaining indicator against the cell's discharge curve during that first cycle — skipping it causes the indicator to read inaccurately from the start.

Dead battery indicator on the Evolt E-450 with a partially charged replacement cell

The E-450 maps its battery indicator to voltage thresholds set during the first charge cycle. A new cell that hasn't completed that cycle presents a voltage profile the BMS doesn't recognise, so it defaults to a low or dead reading even when the cell carries a usable charge. This is a calibration gap, not a fault with the cell. Run one full charge-to-discharge cycle and the indicator will track correctly afterward.

Battery percentage jumping erratically on the Evolt E-620 mid-shoot

The E-620 samples cell voltage at short intervals and maps the reading to a percentage table tuned to the OEM discharge curve. A replacement cell with a slightly different mid-range discharge slope hits voltage points earlier or later than the table expects, causing the display to jump forward or back between shots. This is most visible between 40–70% on the indicator. It stabilises after two to three full charge cycles as the BMS updates its reference points. If it persists past three cycles, check that the charging voltage reaches 8.4V at the end of each charge.