I've got a Victron system with a Multiplus 24/3000, 5 smart MPPT charge controllers, CerboGX, Smartshunt and some Weize lifepo4 batteries.
Today all of the MPPT's stopped charging at the same time. They all showed "battery temperature -1c" which is of course too cold to charge but the batteries were at least 24°c. They were all showing PV array voltage of >40v, bulk charging mode, battery voltage around 26.5. I went ahead and shut everything off, even disconnecting the batteries. When it all booted back up, same thing. The only battery temperature sensor is actually connected to the Multiplus and I didnt think it shared that data over the VE.smart networking because it isn't on that network at all. Its only connected to the CerboGX of course.
I noticed in Victron Connect that the MPPT's were reporting that they were getting battery voltage and battery temperature from the Smartshunt but there is no temperature sensor connected to it - only voltage. So I removed the Smartshunt from the network and the MPPT's still wouldn't charge. So I removed one MPPT from the network and it began charging. I did the same for all the others and added them back into the network and they're all charging as normal.
What I dont understand is where that battery temperature data comes from and where it went wrong. In the trends tab in Victron Connect, I was able to pull up a graph of battery temperature. It was showing in the 30°c range and then suddenly dropped to -1c. Now the battery temperature is greyed out in Victron Connect trends. That is what I would've expected but somehow it was there before. I kind of want to know why because it stopped my solar charging completely. My MPPT's are running the latest firmware, v1.61 and I have (3) 100/20's and (2) 75/15's.
