Chcnav XB-2 GNSS Receiver Replacement Battery 7.4V 3400mAh

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

This is a 7.4V, 3400mAh Li-ion replacement for the Chcnav XB-2 battery pack. It fits the i50 GNSS receiver along with the M3, M6, and T3 models that share the same power architecture. Capacity is 25.16Wh — matched to the original spec.

• i50, M3, M6, T3 shared platform: These four Chcnav models run the same 7.4V battery rail, use the same physical form factor, and share BMS handshake logic — so one pack covers the full group without any firmware or connector mismatch.
• Bench tested on actual hardware: We cycled this pack through multi-constellation tracking loads on the i50 platform. The BMS held voltage within spec across satellite lock, active data logging, and Bluetooth transmission simultaneously.
• Field calibration before first deployment: After fitting a new pack, run a full calibration cycle through the i50's instrument menu before heading into the field. The receiver maps battery state during this cycle — skip it and the low-battery warning triggers early on the first real session.

BMS lockout after the i50 sat unused in a carry case for months

When a Li-ion pack self-discharges below roughly 2.5V per cell, the BMS enters a protection state and blocks normal charge input. The i50's charge circuit won't wake a pack in this state using standard charging alone. To recover it, apply a trickle charge at a low current — many quality chargers have a recovery or "wake" mode for this. Once the pack climbs above 3.0V per cell, the BMS releases and normal charging resumes.

i50 shuts down mid-session despite showing adequate charge on screen

This happens when sustained sensor and radio load pulls the pack voltage below the BMS cutoff threshold — even if the display indicator was reading mid-range. The i50 draws harder during simultaneous GNSS tracking, internal logging, and active radio link, and an aged or cold pack can't hold voltage under that combined load. A new pack at full capacity handles this draw without voltage sag triggering the cutoff. Confirm the pack is fully charged — above 8.3V open circuit — before starting a long field session.