While it is troublesome to get to the best thing to do is add a LED across the D and "+" terminal on the controller. Operational errors will cause the LED to flash a number of times. The number of flashes depends on what kind of operational error was recorded. Each flash will last ľ second. After the actual number of flashes there will be a delay with no flashes, so that the sequence for each error recording is repeated every 4 seconds.
- Battery protection cut-out (The voltage is outside the cut-out setting)
Standard low voltage cut-out would be 10.4 volts, cut-in would be 11.7 (at the controller)
- Fan over-current cut-out
(The fan loads the electronic unit with morethan 1A peak).
- Motor start error (The rotor is blocked or the differential pressure in the refrigeration system is too high (>5 bar)).
- (If the refrigeration system is too heavily loaded, the motor cannot maintain minimum speed at approximately 1,850 rpm).
- Thermal cut-out of electronic unit (If the refrigeration system has been too heavily loaded, or if the ambient temperature is high, the electronic unit will run too hot).
If you don't see any flashes I would look at power connections, especially ground. It is OK to run 24/7 if you power system can handle. You don't specifically say how you monitor your battery health and or charging habits so I would lean towards low voltage issues.