Olympus EPOCH 650 Replacement Battery 10.8V 5200mAh

Olympus EPOCH 650 — 10.8V Li-ion Replacement Battery (600-BAT-L-2)

This is a 10.8V, 5200mAh Li-ion battery for the Olympus EPOCH 650 portable ultrasonic flaw detector. It fits the EPOCH 650 directly, using the same OEM part number 600-BAT-L-2 (also cross-referenced as 100559-05 and U876005B). Use it for field inspections, thickness measurements, and sustained nondestructive testing sessions where the instrument runs continuously under probe load.

• EPOCH 650 pack compatibility: The EPOCH 650 uses a 10.8V three-cell Li-ion configuration with a BMS that handshakes with the instrument's power management circuit. This replacement matches that voltage rail and connector pinout, so the instrument reads charge state correctly from the first boot.
• Bench tested on actual hardware: We ran this pack through probe initialisation and sustained ultrasonic pulse sequences. The BMS held stable across repeated transducer power-up events — no false cutoffs triggered during the current spike at probe activation.
• Post-install calibration cycle: After fitting this battery, run a full calibration cycle through the EPOCH 650's instrument menu before field deployment. The instrument maps battery state during calibration — skipping this step causes premature low-battery warnings during your first measurement session, even with a fully charged pack.

BMS lockout after the EPOCH 650 sat unused in a carry case for months

Li-ion cells self-discharge during storage. If the EPOCH 650 sits unused long enough, the pack can drop below the BMS's minimum recovery threshold — typically around 2.5V per cell — and the protection circuit latches into a low-voltage lockout state. In this state, the instrument will not power on and the charger may show no activity. To recover, connect the battery to an OEM-compatible charger and leave it for 20–30 minutes without interruption — the charger's precharge stage trickles current in below the normal charge threshold, and the BMS will release once cell voltage climbs above 3.0V per cell. If the charger LED does not change state after 45 minutes, the cells have gone below recoverable voltage.

EPOCH 650 display showing unstable or jumping battery percentage at reboot

The EPOCH 650's charge indicator recalibrates its voltage-to-percentage mapping against the cell characteristics of the installed pack. A new battery has slightly different open-circuit voltage curves than the depleted original, so the instrument's indicator may read 40% on boot, jump to 70% after a few minutes of operation, then stabilise — this is the instrument updating its reference, not a fault with the pack. Run two full charge-discharge cycles through normal field use to let the instrument settle its readings. After those cycles, percentage display at reboot should track consistently from 100% down to the low-battery warning at approximately 10.2V pack voltage.