Quote:
"Also, the terminals were clean when I took it in and yesterday there was some of that greenish crud visible on at least a couple terminals. We dry camp almost exclusively and the normal discharge level is 12.2 before we move on and it gets recharged"
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The terminal problem does not happen from a week in the shop. Interstate batteries are on the bottom of my list from past experiences in past trailers.
Chances are "nil" on getting new batteries by blaming the shop. From your replies above, you did not actually open the battery-compartment and check batteries right before hauling the RV in.
Your charger may be overcharging batteries since you say you did clean terminals at a earlier time. It helps to spray a battery protectant on the terminals after cleaning.