I have a bank of 4x 100Ah AGM batteries connected to my Multiplus. Even if the battery voltage is down to 12v at the point I start charging, the Bulk phase lasts seconds. If I use any charge curve apart from fixed I also end up with silly scenarios e.g. the Multiplus going to float with a charge rate in excess of 20A!
I have connected a VE.BUS smart dongle with both temperature and voltage monitoring. I did this to rule out any issues relating to voltage drop.
I have also noted that if I enable the Multiplus battery monitor, SOC is ALWAYS 100% - no matter the battery voltage, charging status or load on the battery etc. This seems very wrong to me. I’ve tried charging with the Multiplus battery monitor setting disabled and see a marginal improvement but not what I’d expect in terms of charging behavior.
I have a Smartsolar MPPT which in the summer months keeps the batteries charged nicely. However, in the winter months, I rely on the Multiplus (Fed AC by a generator) and it really isn’t behaving anywhere near as well.
Have I got the Multiplus configuration incorrect somehow or does this permanent 100% SOC indicate some sort of fault?