Half of my batteries are setting on a shelf over the winter. I need a way, other than using my 100a HF load tester, to load test them and not use the starter. Some are heavy duty deep cycle batteries for a trolling motor and dump trailer.
The dealer uses a small hand held unit that he can electronically measure the battery's condition. The first time he told me my truck battery was getting sick, he was right on. I take what the dealer says, then varify it.
I guess I'll have to ask my GMC dealer what kind of unit he uses. It's like a hand held computer device he punches in info and actually measures the CCA. The boys at Rural King have a similar device.