Morning everyone,
I have 2 MPPT chargers attached to a multiplus 2 12/3000 and 4 x 110 Ah Victron 12v batteries, which has been reliably able to invert 2.4KW for the last 12 months as needed onboard.
Now, when any load of ~2.1Kw or higher is being pulled, the inverter will reset. We can pull under 2.1Kw and it will function correctly with no issues.
I confirmed all 4 batteries were functioning with a multimeter, and the GX panel also confirmed that the multiplus was receiving 13.4V.
On watching the inverter front panel, no warning lights are on but it lit up the “low battery” as it reset itself and dropped all the power. (Power came back within a few seconds, but enough for the toaster/oven/whatever was pulling the load to switch off).
Previously this system could invert when the batteries were not at 100% without any issues, but I am stumped as to why it resets itself when asked to invert a load that previouisly it could handle with ease.
I can’t see anything obvious in the settings (none have been changed), so I am wondering if it could be a physical failure somewhere, but then if so it shouldn’t work at all.
Any advice or suggestions would be most welcome,
[UPDATE] Thank you all for your responses. I tracked down the issue to be 2 blown 100A mega fuses in the Lynx distributor. I have 4 x 110Ah Victron LiPo4 batteries and two of those had blown. Replacing them meant that I can now fully invert.
I think the reason why they blew was a loose connection on the 150 70 MPPT (the installer had not put a locking washer on).
many thanks
Martin
OK a good set of batteries then with ample capacity so they should be good.
When the multiplus reports 13.4V that may be the battery voltage from the shunt, not the voltage at the multiplus terminals. You may have developed a poor connection in your positive or negative cables through something coming loose, or an isolator failing, this gives high resistance and voltage drop. Start a load on the Multiplus that it can sustain, say 1 to 1.5kW. Then with your multimeter check the battery terminal voltage and the terminal voltage on the Multiplus. Then check from battery + to Multiplus + and then from - to -. Check from battery - to each connection looking for a large change in voltage. Check all terminals are tight, all crimps tight etc.
Many thanks PWFarnell,
I will do that the next time I am onboard & check voltage differences throughout the system. In another thread
I found that a busbar nut had come loose ( it must have been from engine vibrations ) - the next time I am onboard I will be checking ALL connections/crimps etc
In my head I imagine that connectivity is binary - it works, or it doesn’t but of course poor connections can give a curveball reading - not a false positive but the problem might not be obvious.
Many thanks again - I will keep you & this thread informed on an update when I find one.
Loose connections do not break contact, they increase the resistance and with low current draw have little effect. Make sure that all your busbar nuts have spring washers under them to avoid them coming loose and consider a torque wrench to get the corrdct tightness.
