About this replacement
Flir ThermaCam E2 / ThermaCAM EX320 — 7.4V Li-ion Replacement Battery (T198258)
This 7.4V 2600mAh Li-ion battery replaces the original T198258 pack in the Flir ThermaCam E2 and ThermaCAM EX320 handheld infrared cameras. It also fits the E65 and the extended compatibility list covered by OEM references T199366 and 1195106. Voltage and cell count match the original to maintain BMS handshake with the camera's power management circuit.
- Multi-model fit across the ThermaCam lineup: The ThermaCam E2, EX320, and E65 share the same 7.4V two-cell Li-ion platform, connector pinout, and BMS communication protocol — which is why a single replacement pack covers all three without adaptation.
- Bench tested on actual hardware: We cycled this pack through the E2's combined load — IR detector heating element, display backlight, and image processor running simultaneously — and confirmed the BMS held voltage without triggering low-battery cutoff under that combined draw.
- Detector warm-up after battery swap: After fitting a fresh pack, power on the camera and wait at least 60 seconds before taking any measurements. The uncooled microbolometer detector requires the internal electronics to reach thermal equilibrium — readings taken before this stabilisation window will show calibration drift.
Thermal accuracy degrading before the battery indicator shows low
The ThermaCam E2's IR detector is voltage-sensitive. As cell voltage drops toward 7.0V, the detector's reference voltage rail begins to sag before the fuel gauge registers a low-battery warning. This causes temperature readings to drift — typically showing targets as cooler than actual — without any visual alert on screen. If readings look inconsistent during an inspection, check the battery indicator manually and swap the pack if either cell is reading below 3.5V.
Camera shutting down mid-inspection on a battery that reads full
The E2 draws a spike load every time the detector's thermal stabilisation circuit cycles — this happens automatically every few minutes during continuous use. If the replacement pack's BMS has a conservative overcurrent threshold, that spike can trigger a protection cutoff even when the state-of-charge reads high. We saw this on bench when ambient temperature exceeded 30°C, which raises internal cell resistance and amplifies the voltage sag during the spike. Condition the new pack with two full charge-discharge cycles and confirm the camera completes a full shutter calibration cycle without cutoff before taking it into the field.