Olympus 38-BAT Ultrasonic Thickness Gauge Replacement Battery 10.8V

Olympus 38DL Plus Ultrasonic Thickness Gauge — 10.8V Li-ion Replacement Battery (38-BAT)

This 10.8V, 3400mAh Li-ion battery replaces the OEM 38-BAT pack in the Olympus 38DL Plus Ultrasonic Thickness Gauge. The 38DL Plus is a handheld thickness measurement instrument used in industrial inspection, pipeline surveys, and corrosion monitoring. It draws sustained current through its probe circuit during active measurement sessions, so stable voltage delivery matters.

• 38DL Plus and Epoch 4 compatibility: The 38-BAT form factor is shared across the 38DL Plus and Epoch 4 platform. Both instruments use the same 10.8V three-cell configuration, the same connector pinout, and the same BMS communication handshake — which is why one pack covers both.
• Bench tested on actual hardware: We ran this pack through probe initialisation cycles and sustained measurement loads. The BMS held voltage within spec across repeated transducer power-up events and did not trip during continuous logging sequences.
• Calibration cycle after install: After fitting this battery, run a full calibration cycle through the 38DL Plus instrument menu before heading to site. The gauge maps battery state during calibration — skipping it causes premature low-battery warnings to appear during your first active measurement session, even with a full charge.

BMS cutoff when the 38DL Plus probe initialises

When the 38DL Plus powers up its transducer, the probe circuit draws a sharp current spike in the first half-second of initialisation. A weakened or deeply discharged cell can drop below the BMS undervoltage threshold at that exact moment, causing an immediate shutdown that looks like a dead battery. This is a protection trip, not a failed pack. Charge the battery fully to 12.6V before the next power cycle and the BMS will reset automatically.

Readings resetting or dropping out mid-logging session

During long data-logging runs, the 38DL Plus sustains continuous power to the probe, the display, and the internal memory write circuit simultaneously. If the cell voltage sags under that combined load — typically below 9.5V per cell group — the instrument resets its active session to protect stored data. This is a voltage-sag event, not a firmware fault. A freshly charged pack at 12.6V eliminates the sag and keeps the session stable from start to finish.