Interesting info on 6s vs 12s in golf cars. Does relate to RVing in a way especially if you have one bank for big inverter only and another bank for low amp stuff. Hard to apply when you have four batts doing everything, but it gives you an idea which approach might suit you.
Anyway, I checked out this place and the guy
who told me about it didn't have it quite right. It turned out he was there last year and things have changed a bit.
It is a serious golf car dealership, buy or lease, with showroom and some $8,000 plus cars sitting there. They are only into batteries by accident as it were, where somebody buying a used car wants all new batteries, so if the old ones test not bad they will sell them to anybody looking for them. Prices vary a bit by age 70-60 $. The old ones that fail their test go to junk.
They are switching over from four 12s to six 8s since last year and have very few old 12s anymore. The 12s are T-1275s (150AH) not the big J18s I imagined.
I was tempted to get two off a pallet of the oldies but goodies, which are two years old. The fellow there said they tested them and got 86 minutes so they were at least 80% still ok. I tried to find the RC on the label and we went round and round over price etc and then it came out that they don't use RC. They use 100 minutes of golf car run before it needs recharging as the standard. So these tested at 86. That was two months ago and they have been on the pallet out back since. More pestering by me about what tests I could do before paying money.
Then the boss of the place came leaping out of his office and said, "Is this all about TWO batteries?" and ranted a bit about fooling around with testing etc and said, "Just take them! Go away, we don't have time for all this" ( He was too busy with his $8,000 cars I guess ) So I did what I was told and took them. :)
So that was my adventure at the golf car place. Now I have to find out if these T-1275s will even hold a charge and all that--a new project---just what I need!