The SmartGauge is a little mind-bending compared with regular amp-hour counting... that is until you realize what matters is where you stand compared to the REALISTIC value today for your battery bank capacity. I can see how having both amp-hour counting and the honest state of charge reading could be the best of both worlds. So, if your 1000 amp-hour house bank is drawn down 100 amp-hours and the SmartGauge says you are at 80% state of charge (SOC), then your real bank capacity is only 500 amp-hours, not 1000. That would be useful to know.

So Enersys reported that the SmartGauge is incredibly accurate when they tested with TPPL batteries. Those are a type of AGM style battery but different. I wonder what setting should be chosen for TPPL batteries when setting up the SmartGauge.

I'm tempted to get a SmartGauge only the combination of charging options, battery bank size and type, conservation measures I've done etc., probably mean that I don't need that kind of gadget if I already have reasonable amp-hour counting. Especially true if I aggressively top off the batteries regularly.