Accurate surface temperature monitoring is essential for analyzing and controlling the thermal behavior of battery cells and similar electrochemical systems. This study compares contact-based and contactless measurement methods, highlighting that larger sensor areas can lead to inaccurate readings due to ambient temperature influence. Thermal camera measurements closely matched those of a small Type-K thermocouple, confirming their reliability when non-reflective coatings are used. A low-cost FLIR Lepton 3.5 camera produced results comparable to a high-end InfraTec VarioCAM HD after calibration. In contrast, the DS18B20 sensor underestimated temperature due to its larger sensing area, though insulation improved its performance slightly.