Possible Causes:
- The voltage cut-off is set too high. The in-built settings are: 10.0; 10.7 and 11.8 volt. The unit will run the longest when it is set at the lowest voltage.
- The surrounding temperature is too high for the cooler and it is ‘running hot’. Keep the cooler out of direct sunlight and make sure there is plenty of good airflow and ventilation.