I can't understand why that would damage the lead acid grp27's batteries I use. But he does allow that in colder climates you can go longer because of the slower self discharge rate.

Like you say, it's a choice. I'm comfortable with fully charged stored batteries. I can't say that when I charged them periodically over the winter(I've been doing this for more than a couple decades), they lasted any longer. If I knew I could consistently get, say 6 years out of the standard GRP 27's, instead of the 5 I'm used to, I'd take the extra effort.

Thanks for posting that.