Originally Posted by BandJCarm
OK, makes sense but I'm still trying to figure out if that Bogart unit measures one battery only? IF so, do you need two? Or what?
Bogart will actually monitor two, but only measures current in and out of one of them. That is because when you have a bigger house bank it is usually connected as a single bank of either 12 volt units in parallel or 6 volt units in series and parallel. My RV has 4 12 batteries in parallel and they are treated (charged and discharged) as a single bank. The second Bogart monitor connection is for the chassis battery in an RV and they only display voltage from that unit.
When managed correctly, a bank of multiple batteries can be treated as a single large battery. Sure you might get a bad cell eventually, but that will be long after the bank is ready for replacement. Since Bogart and Victron systems act like bank clerks and only measure discharge (withdrawals) and charge (deposits) it is a good idea to take a look at all batteries and cells every few months with a real hydrometer. This will confirm that all cells are good and that you don't need to equalize your batteries with a 4 hour charge cycle of maybe 15 volts. Few people actually equalize, although Bogart has a companion solar charge controller that has an equalization option and it communicates with the battery monitor for a display and current measurements.