[Don L]

I fully charge them and even equalize for a few hours, disconnect them, and leave them on the boat. This spring when I hooked them back up they were still at 12.5V.

 

[Don L]

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

Why? Charging them up at the start of layup and disconnecting them (ie doing nothing) works fine and in the Spring the batteries are at 90+% SOC.

Doing nothing works pretty darn good.