Added a new battery monitor...(Aili)
Battery Monitor == Fun! Plus: How to avoid a common mistake regarding AH total I have a couple 2015 Thor Majestic 28a RVs. I added a 2nd 12v battery to the coach (they only came with one). My ba...
Forum Discussion
The main point is that you need to know what your monitor really does, whatever model you have, so you won't be misled by it. And cross-check whatever it says.
I like to compare the battery voltage in the morning when the furnace is not on at the time and no solar yet- the closest it can be to "resting voltage"- and the SOC that goes with that voltage, to the AH count.
I have an idea of the capacity of the battery bank at the time as adjusted for temperature and age etc, so I can do the math on AH down vs that est. capacity.
I do not use the %SOC the monitor could show--that is where folks go wrong, believing that % without cross-checking to see if it is reasonable.
If the two methods for calculating SOC "match" closely enough, all is good. If not, then the search starts for why not? Something somewhere is wrong. Voltage can be wrong due to a mystery load. AH can be wrong from the monitor not being reset properly, or a loose monitor display wire on the shunt getting the amps wrong. Something, somewhere.
I like to compare the battery voltage in the morning when the furnace is not on at the time and no solar yet- the closest it can be to "resting voltage"- and the SOC that goes with that voltage, to the AH count.
I have an idea of the capacity of the battery bank at the time as adjusted for temperature and age etc, so I can do the math on AH down vs that est. capacity.
I do not use the %SOC the monitor could show--that is where folks go wrong, believing that % without cross-checking to see if it is reasonable.
If the two methods for calculating SOC "match" closely enough, all is good. If not, then the search starts for why not? Something somewhere is wrong. Voltage can be wrong due to a mystery load. AH can be wrong from the monitor not being reset properly, or a loose monitor display wire on the shunt getting the amps wrong. Something, somewhere.
