UNI-T ICR18650 Thermal Camera Replacement Battery 3.6V 2600mAh

UNI-T UTi220B / UTi22A Series — 3.6V Li-ion Replacement Battery (ICR18650)

This is a 3.6V, 2600mAh Li-ion ICR18650 cell replacement for the UNI-T UTi220B and UTi22A thermal imaging cameras, including both standard and Heavy Duty variants. It restores full battery capacity to these handheld infrared cameras used in building diagnostics, electrical panel inspections, and HVAC surveys. Voltage and capacity match the original cell specification exactly.

• UTi220B and UTi22A compatibility: Both camera variants share the same single-cell ICR18650 battery bay, connector orientation, and BMS handshake protocol. The Heavy Duty versions use identical internals — only the housing differs. One cell fits all four listed models.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on thermal camera hardware. The BMS responded correctly to the combined load from the detector heating element and the display backlight without triggering early protection cutoff.
• Flat-surface calibration before first use: Point the camera at a uniform flat surface and let the shutter cycle once before your first inspection. This forces the microbolometer to re-establish its offset correction with a fully charged cell, which a depleted original battery may have skipped during its last sessions.

Why the UTi220B shuts down mid-inspection on a new battery

The UTi220B runs two constant power draws simultaneously — the infrared detector's heating element and the LCD display. During an active inspection, this combined draw pulls the cell voltage down faster than the fuel gauge can update. If the replacement cell has a conservative BMS protection threshold, it can trip the low-voltage cutoff while the camera still shows two battery bars. The fix is to ensure the cell is fully charged to 4.2V before use and to avoid powering on in ambient temperatures below 5°C, where cell impedance spikes sharply under the detector startup surge.

Thermal accuracy drifting before the battery indicator reads low

The microbolometer in the UTi220B is voltage-sensitive. As cell voltage drops from 4.2V toward 3.6V during a session, the detector's reference voltage shifts slightly, and temperature readings can drift by 1–3°C before any low-battery warning appears. This is not a camera fault — it is a cell chemistry behaviour. If readings look inconsistent late in a session, check that the cell is charged above 3.8V before starting critical measurements. Recharge and run the flat-surface shutter cycle again to reset the calibration baseline.