I came up with the same type of thing. I have two battery banks which are paralleled together or run separately. I have a digital DC voltmeter for each back. I also have a DC ampmeter installed in the line feeding the battery switches. This allows me to monitor my DC load as well as monitoring how much current is being sent to battery banks when the converter is in its charge mode.
These three meters came from Sure Electronics Ebay-China and i mounted them in a Lowes speciality large opening three position switch wall plate. This is installed in a three position switch wall box. Turned out great. After i was done and all was working then I said I wonder why I just didnt get a Trimetric TM2025-RV battery monitor panel. It has built-in settable alarms conditions...
I still like my little three meter switch box panel meters... Probably because I made them myself.
I will run my battery banks down to around 11.9VDC which is near 50% charge state before re-charging back to the 90% charge state (12.6-7VDC) the next morning using my 2KW Honda generator connected to the trailer 30AMP shore power cable.
then i can do it all over again for the next day/night battery run. having battery monitor meters "ON" during the process makes it a piece of cake for us.
hasn't gone dark on us yet haha... I have heard the Inverter alarms a couple of time however...
