I have a solar system in my motorhome going to an odyssey pc1800 battery & have BMV700 monitor. There’s a cytron cyrix ct intelligent battery combiner between the starter and pc1800 allowing charge to go both ways.
I’ve had system 5 years no issues. But recently (in cold weather) started battery has run flat (below 8 volts) and van wouldn’t start. This has happened twice. The BMV700 was showing a voltage of 7.75.
Here’s my issue, the BMV700 seems to be displaying the starter voltage. As normally even through the winter when van unused there’s always a small charge and ive never see a lower voltage than about 11.75. Then my starter goes flat and voltage displayed is 7.75. The guy who I talked assured me the bmv is/should be monitoring the leisure battery -which doesn’t seem low all. Lights good all history seems good etc.
What’s going on? Any pointers appreciated!