I have a MPPT 75/15 powering my caravan. It’s been working fine for the last two years. I upgraded from AGM to Lithium batteries. However, I now have no 12 v output. I have checked and there is 13.7 v in, but the output voltage is between 0.25 and 0.4 volts.
The output was set to BatteryLife. I changed to Always On. Still no output.
The App is not showing any errors.
What am I doing wrong, or is there something wrong with the MPPT?
Somehow got a short circuit or high load on the output terminals during battery swap over and damaged them. You may need to swap your load to the battery. The load terminals are not high current, limited to 15A, if on battery restart you have something like a small inverter on the output this could draw a high surge current and overload / damage the load output.