Get the group 1 size 6V Costco brand Kirkland battery
Save your receipt
If the battery goes bad within 4 year warrantee period they will replace it no questions asked and not “pro rated you pay the difference”
Straight up new battery with a new 4 yr warrantee

I don’t have a Costco membership but all my family does and since they warrantee so good I use them for batteries.
I’ve have only good experiences with Kirkland brand batteries, maybe I’m lucky.
My brother turned me onto Costco batteries when he let one freeze to death and he showed me how well they treated him
-s