Originally Posted by KatanaPilot
Completed install today of new AGM coach batteries along with a Victron dual battery monitor.
While installing, did a full test of the Battery Control Center (BCC) and the integral Battery Isolation Monitor (BIM). I can unequivocally say that on my 2015 Forester MBS with the Precision Circuits, Inc. BCC, that the converter/charger (Progressive Dynamics PD9260) DOES charge both the chassis batteries and the coach battery when on shore power...Pretty definitive to me.
Nice test, and it also proves that Precision has made some significant progress on their BCCs over the years. Yours (and hopefully mine as well) is a lot smarter than the older units. They used to simply monitor the voltage from the charging side and pull in the solenoid when it went above a certain voltage (like 13.5 or so.) What that did was to keep the solenoid running for weeks or months when the coach was plugged in to shore power and the converter was running. This eventually would wear out the solenoid from long term heating. Seems that the BIM is smarter now and only fires the solenoid when the voltage on the charging side is over the magic level...and the uncharged side is below another set point and actually needs a charge! Nice fix and it should make the system much more reliable in the long term.
It also should comfort people with solar who hated to see some of their precious amperage go into heating a solenoid rather than charging a battery. It was especially irritating to them since they could hear the solenoid click in and out when a cloud went in front of the sun!
I used to ignore their "when the battery needs a charge" but I guess you have proven that it is now true with the newer BCCs. I will look for that with my Trimetric as well.