Battery monitor pricing

full_mosey wrote:
So do we now have a definition of fully charged without float?

Yes we do, I think ... but I thought I always did.

I merely use K.I.S.S. to keep my RV life simple. Whenever my coach battery bank ammeter shows zero plus or minus current flowing in the battery bank's negative cable (that's where I installed the ammeter's shunt) going to the vehicle's ground point while converter or alternator voltage is being applied to the battery bank ... I call my coach battery bank fully charged.

I see "zero" when my digital ammeter's readout shows 00.0 ... but since it has only a 3-place readout, at this point - allowing for instrument repeatability errors - up to +0.1 amps or -0.1 amps could probably still be flowing through the shunt. But once the ammeter indicates this - it's a solid reading. Leaving the converter or alternator still connected to them, the AGM batteries do not pass any more current beyond this reading unless I run them down some then fire up the converter or alternator again. I call this zero ammeter reading point a "hard stop" in the AGM batteries' charging regimen. I've never seen this with good old liquid acid batteries ... they just continued to sit there and pass 1-2 amps for days.

As I've stated many times, our AGM battery bank reaches this hard stop in recharge current acceptance from the alternator within only a very few hours of driving. Reaching this point of course takes longer using only the 13.6 volt fixed voltage converter - as is to be expected from the recharge time charts/graphs. In this drycamping situation I do only about 50-90 SOC cycles .... which are of course quicker than what it would take with liquid acid batteries. We don't much drycamp for days at a time in one spot, but when we do I mix in some alternator recharge time to ensure that the AGM battery bank gets to full (a zero reading on the ammeter) once in awhile.

Note BTW, that the recommended float voltage for my Fullriver AGM batteries is around 13.6 volts (@ 77 degrees). I shopped for Lifelines at first, but rejected them (after finally calling the company) because they insisted that a 13.6 volt float voltage was too high for Lifelines. I didn't want to slowly dry out Lifelines, so I went with Fullriver due to their float spec and also after discovering that Fullriver in fact made the AGM batteries for Rolls-Surette.