According to the instruction manual, it should have protection, but I couldn't test it myself because my batteries were always well charged in the camper.
Ciao Dgeisseler I hope this helps you : Copied from the instruction manual: A two-stage (CDF18) / three-stage (CDF26, CDF36, CDF46) battery monitor built into the unit (CDF26, CDF36, CDF46) battery monitor protects your vehicle's battery from discharging too deeply. 6.4 Using the battery monitor If the cooler is operated in the vehicle with the ignition switched off, If the cooler is operated in the vehicle with the ignition switched off, the box switches itself off as soon as the supply voltage drops below an adjustable value. falls below an adjustable value. The cooler switches on again as soon as the restart voltage is reached by charging the battery. is reached.