[hellosailor]

Simple and not altogether unreasonable solution would be to get a Deltran Battery Tender or similar gizmo, which plugs into the wall and keeps a small charge on your battery during "storage".

Wet lead batteries self-discharge all the time, and if they sit without any charging to compensate for that, they will take internal damager from sulphiting, with a permanent loss of capacity.

So, by all means question which gizmo works best or properly, but any one of them should beat nothing at all.

 

[hellosailor]

"Why?"

Because you can't SEE the damage and the odds are you don't have access to the equipment to do any real meaningful SOC testing. The folks who do have that and use that, the battery makers, all have an interest in selling you new batteries as often as they can.

And yet, they ALL will say what I just said. Thirty days, and you've probably damaged the batteries. 90 days, and you've definitely damaged the batteries.

You think doing nothing works well enough? OK, do nothing. They'll be happy to sell you new batteries every three years instead of every six or eight years.

Not my opinion. Objective fact, repeated and confirmed by every business that's in the business of making batteries.

 

[hellosailor]

Maine-
Gels are nothing like wet lead acid when it comes to long term and sulphating. You know that as well as I do.
And obvisouly, all chargers and maintainers aren't built to the same quality.

But what? Do you think the battery companies are all telling the same lie, that the batteries will sulfate and lose capacity? All lying because, what, they get paid back by the battery "tending" makers?

I don't doubt your equipment, your tests, or your veracity, but I also don't think the entire battery industry is engaged in some grand conspiracy to misinform the public about how batteries should be treated in storage. Not that it isn't possible, just that it is more likely there's some other reason that your observations don't match their statements.