HUACE M600 Compatible Battery 7.4V 2600mAh Li-ion

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

This 7.4V, 2600mAh Li-ion battery replaces the original pack in HUACE M600, R30, X20, and X90 field instruments. These are portable survey and measurement devices used on construction sites and in electrical testing applications. Voltage and capacity match the OEM spec to keep the instrument's power management system satisfied.

• M600 / R30 / X20 / X90 platform compatibility: These models share a common 7.4V battery architecture and the same physical form factor — 70.40 × 38.70 × 20.50mm — along with a matched BMS handshake voltage range. Swapping between these units does not require a different cell configuration.
• Bench tested on actual hardware: We ran this pack through repeated probe-initialisation cycles on the M600 platform. The BMS held steady through the brief current spike at sensor power-up, which is the point where weak or undersized cells typically trip the protection circuit.
• Post-install calibration cycle: After fitting this battery, run a full calibration sequence through the instrument menu before going to site. The M600 maps battery state during calibration — skip this step and the instrument will throw premature low-battery warnings on the first measurement session, even with a full charge.

BMS lockout after the M600 sat unused in a carry case for months

Li-ion cells self-discharge over time. If the pack voltage drops below approximately 2.5V per cell — around 5.0V total for a 2S pack — the BMS trips into deep-discharge lockout as a cell protection measure. At that point, the instrument will not power on and the charger may show no activity or a fault light. The fix is a low-current pre-charge: use a compatible charger that supports recovery mode, or apply a brief trickle charge directly to the pack terminals at under 0.1A until voltage climbs above 3.0V per cell. Once the pack reaches roughly 6.2V, the BMS will re-initialise and normal charging resumes.

Readings drifting or resetting mid-session during a logging run

Sustained sensor load — particularly when multiple probes are active or the instrument is logging continuously — draws more current than standby operation. If the cell capacity has degraded, voltage sags under that load and the instrument interprets the dip as a low-battery condition, interrupting the logging session or resetting the display. This is not a firmware issue — it is a cell output problem. Check resting voltage after a full charge: a healthy 7.4V Li-ion pack should rest at 8.2–8.4V. If resting voltage reads below 7.8V after a full charge cycle, the cells are no longer holding capacity and the pack needs replacing.