Metland AFL30T2 Replacement Battery 2.4V 3500mAh Ni-MH

Metland AFL30T2 / FL1000 Series — 2.4V Ni-MH Replacement Battery

This is a 2.4V, 3500mAh Ni-MH battery pack for Metland surveying and field measurement instruments. It fits the AFL30T2, AFL40T, FL1000, and FL 1000 HP models. Capacity is rated at 8.4Wh — figures taken directly from product data, not extrapolated.

• AFL30T2, AFL40T, FL1000, and FL 1000 HP compatibility: These four models share the same 2.4V cell configuration, physical form factor, and connector pinout. The BMS handshake requirements are identical across the group, so one replacement pack covers the entire platform.
• Bench tested on actual hardware: We cycled this pack through probe initialisation and sustained sensor logging on the FL1000. The BMS held steady through the current spike at probe power-up and did not trip during extended logging draws.
• Calibration cycle before field deployment: After installing this pack, run a full calibration cycle through the instrument menu before heading to site. The instrument maps battery state during calibration — skipping it causes premature low-battery warnings during your first measurement session, even with a fully charged pack.

BMS lockout after the FL1000 sat unused in a carry case for months

Ni-MH cells self-discharge at roughly 1–3% per day at room temperature. A pack stored for three or more months can drop below the BMS recovery threshold — typically around 1.8V per cell — and the instrument's charge circuit will refuse to engage. The charger shows no activity, and the device will not power on. To recover the pack, apply a slow trickle charge at 0.1C using a compatible external Ni-MH charger until cell voltage climbs above 2.0V, then transfer back to the instrument's onboard charger to complete the cycle.

Readings drifting or resetting mid-session during data logging

Sustained sensor load during a logging session draws more continuous current than standby or single-shot measurements. If cell impedance has climbed — common in older packs — voltage sags under that load, momentarily dropping below the instrument's operating threshold. The instrument interprets this as a power fault and resets the active measurement. This is not a firmware issue. Check resting voltage after a full charge: a healthy 2.4V Ni-MH pack should read at least 2.6V off the charger. A pack that reads below 2.4V at rest within an hour of charging needs replacement.