Alan, From my article on battery charging and care on my personal website (link follows): https://gilwellbear.wordpress.com/category/boat-technical-topics/electrical-topics/battery-topics/batteries-charging-and-care/ There are several aftermarket coulomb counters available today, including the Bluesea Systems M2 DC (p/n 1830), Victron BMV-770 or BMV702, Xantrex LinkPro and Mastervolt BTM-III. I feel the best choice these days is to get a coulomb counting monitor from the manufacturer of the charger or inverter/charger. Aboard Sanctuary, a Magnum MS-Series Inverter/Charger is installed, and we use the Magnum BE-BMK coulomb counting monitor with the inverter/charger. Hope this helps. Jim > On Nov 29, 2019, at 09:59, Alan Yankie <alanyankie@bellsouth.net> wrote: > Can you recommend a good coulomb-counting monitor? > > Alan > Peg and Jim Healy, living aboard Sanctuary http://gilwellbear.wordpress.com Monk 36 Hull #132 MMSI #367042570 AGLCA #3767 MTOA #3436