I know this is probably a simple problem, but the auto parts stores, and Costco seem to only offer “marine deep-cycle” batteries in the correct battery size (31). Also they list things like cranking amps, and other ratings so I have no way to see how they compare to the current batteries which are US Batteries with 140 Ah reserve capacity.
It seems like ads are pretty deceptive. It seems like there is a problem with shipping the batteries if they have acid in them.
My batteries are 9 years old. I could still go 15 miles on them last summer, but am pretty sure they have lost a lot of that capacity all of a sudden.
Basically, I just want to find a source of size 31 batteries with about 140 Ah that are deep cycle flooded batteries. All I have found is Trojan 150 Ah for $250 apiece: Way too expensive! And several Universal Batteries that are AGM and 100Ah starting at $175: Too expensive, less capacity, but AGM seems good.
Then there are the size 31 Johnson marine batteries that are flooded and cheap that they sell in auto parts stores, about $100, but they don’t list their Ah rating, and, while I’ve heard marine batteries are inferior, these do seem pretty heavy - probably about the same as the US Battery 140 Ah flooded batteries that I have.
At this point maybe I’ll just go with marine batteries, unless someone knows a better way, and not for $250 apiece!
I don’t know of anyone that sells US Batteries similar to the ones I have now, BTW.