I've been using Victron BMV-700. Fit perfect where my old analog volt meter was. I use to use a volt meter to check SOC but with the Victon I no longer have to open the battery boxes to check voltage at the battery. It also tells me if anything is drawing current and how much. Very useful when think everything is off but still show a draw from the light I left on. My batteries a 7 years old so I don't need SOH, I know it's not good.