HUACE M600 Replacement Battery 7.4V 3400mAh Li-ion

HUACE M600 / R30 / X20 / X90 Series — 7.4V Li-ion Replacement Battery

This 7.4V 3400mAh Li-ion pack replaces the internal battery in HUACE M600, R30, X20, and X90 field survey and measurement instruments. It fits handheld devices used for on-site data collection, construction layout, and engineering surveys. Dimensions are 70.35 × 38.50 × 20.65mm — verify your original pack before ordering.

• M600 / R30 / X20 / X90 platform fit: These models share the same 7.4V battery bay format and BMS communication protocol. The cell footprint and connector pinout are consistent across the series, so one pack covers the full range listed.
• Bench tested on actual hardware: We cycled this pack through instrument power-on, sensor initialisation, and sustained logging draws. The BMS handled the probe power-up current spike without tripping into protection mode, and cell voltage held steady under continuous sensor load.
• First-use calibration on survey instruments: After installing a new pack, run a full calibration cycle through the instrument menu before heading to site. The M600 and related models map battery state during calibration — skipping this step causes the instrument to report premature low-battery warnings on the first measurement session in the field.

BMS cutoff when the probe or sensor module initialises

When the M600 powers on, the instrument sends a short high-current pulse to initialise attached probe or sensor modules. An aged or deeply discharged cell has higher internal resistance, so this pulse causes a voltage dip sharp enough to trip the BMS into protection mode. The instrument shuts off immediately after the startup screen — the user sees it as a power-on failure, not a battery fault. A healthy cell at full charge holds above 8.2V under that initialisation load and the BMS does not trigger.

Readings resetting or drifting during an active logging session

Sustained sensor operation draws a steady current that a degraded cell cannot maintain cleanly. Voltage sags below the instrument's operating threshold mid-session, causing the processor to reset — measurement data at that point is lost or corrupted. This is distinct from a full shutdown: the display may flicker or the session counter resets while the unit stays on. If this happens, check resting cell voltage after a full charge — a healthy 7.4V Li-ion pack should read between 8.3V and 8.4V at rest.