Chcnav i50 XB-2 Compatible Battery 7.4V 2600mAh

Chcnav i50 / M3 / M6 / T3 Series — 7.4V Li-ion Replacement Battery (XB-2)

This is a 7.4V 2600mAh Li-ion replacement for the original XB-2 battery pack. It fits the Chcnav i50, M3, M6, and T3 GNSS receivers used in professional surveying and geospatial fieldwork. Voltage and capacity match the factory specification exactly.

• i50 / M3 / M6 / T3 platform fit: These receivers share the same battery bay geometry, connector pinout, and BMS communication protocol — which is why one pack covers all four models. The XB-2 form factor is consistent across the platform, so the same 70.40 × 38.70 × 20.50mm cell assembly seats and latches correctly in each unit.
• Bench tested on actual hardware: We cycled this pack through the i50's charge and discharge sequence, confirming BMS handshake, cell balancing at full charge, and clean cutoff behaviour at the low-voltage threshold. The protection circuit responded correctly to both over-current and over-discharge conditions.
• Pre-deployment calibration on GNSS receivers: After fitting a new pack, run a full calibration cycle through the receiver's system menu before heading to site. The i50 maps battery state during that routine — skip it and the fuel gauge will throw premature low-battery warnings halfway through your first logging session.

BMS lockout on the XB-2 after the receiver sat unused in a carry case for months

Lithium-ion cells left in a discharged state for extended periods can drop below the BMS recovery threshold — typically around 2.5V per cell on a 7.4V pack. When that happens, the protection circuit locks out and the receiver won't power on or charge. Placing the pack on a compatible charger for 15–30 minutes at a trickle rate usually brings the cells back above the recovery floor. If the charger shows no activity after that window, cell voltage has likely fallen below the point of safe recovery and the pack should be replaced.

i50 shuts down mid-logging session despite the battery indicator showing charge remaining

This happens when sustained sensor and satellite tracking load pulls the pack's output voltage below the receiver's operational floor — even though resting voltage still reads as healthy. The indicator is reading a static voltage snapshot, not under-load voltage, so the display looks fine right up until cutoff. Check that the replacement pack is fully charged before the session and that the calibration cycle described above has been completed. A pack that shuts the receiver down at 30–40% indicated charge almost always has a voltage-threshold mismatch caused by skipping that post-install calibration step.