I’ve got a Multiplus II 15000 in island setup that has been functioning for 2,5 - 3 years now in the current setup. This morning it suddenly shut down, indicating low battery / overload. Neither can have been true. The battery was 100% and the load about 400 Watts. The manual states that that could be due to ripple. After turning it off and on again, it only shows the overload indicator (also in the VictronConnect app it says it’s overloaded) and immediately shuts off. I diconnected the AC wiring, but it still says it’s overloaded. I opened the enclosure. The only thing I noticed is that the big ring transformer is somewhat warm (about 42 degC, measured with an IR thermometer).
What batteries do you use (total AH lead or KWh lithium), can you see the inrush current from the batteries when you start, switch to charge only and see it does that?
When you disconnect the positive from the battery of the inverter, how much time it takes before the voltage is half the “start” voltage of the battery terminals of the inverter, seconds or minutes?
Can you measure the battery voltage at startup on the inverter terminals, did you use a dust filter under the inverter, what are your settings in VE-config, do you use a GX-device and what are the settings in there?
If you had before a high ripple for all these years, the change is that the capacitors in the inverter are damaged, but before we conclude they are…you must give us first more information, replies on the questions above.