On our most of our RVs we have kept it simple and used the plug in DC socket type on both interior and exterior of rig, a quick glance and we would have battery voltage and/or which phase our converter was currently charging in. We purchased a better quality unit that displayed battery voltage same as our Fluke, cheaper units were always a few tenths off which could be the difference between bulk and absorption phases. They use such a miniscule amount of power that we never had a need to unplug them, although it was easy peasy to do so.