Just a short caveat: Should you try to design this yourself, be
very careful. Every battery must be isolated so one battery can
never supply power into another one. Usually it's nothing more
than diodes, but the protection must be there. Equally charged
batteries are not equal in voltage and some big currents can flow
if they aren't properly isolated.
I usually just go around and charge each one, one at a time,
about mid-winter. That way I also get a hint, if one's not
holding a charge, ahead of time. As someone said, they should
last that long OK except for the smaller lawn tractor type
batteries, without being charged, unless they're in sub zero
temps.
I'm not sure either, but I'd check to be sure deep charge
batteries are OK to trickel charge; SOME battery I had couldn't
be trickle charged, and the boat batteries are all I can think it
would hve been, but not sure.

Pop


Jim M wrote:
Hello there,

I am from Canada and I have summertime toys that I have
put away
for the winter months. My problems are for maintaining battery
charge..........I have on a very heavily built shelf 3 deep
cycle 12 volt batteries out of my Boat and Rv trailer. Two
regular 12 volt
batteries out of my Corvette and Boat motor starter
battery....smaller 12 volt garden tractor battery and also
smaller12
volt battery out of my ATV quad...amongst a few others that are
out
of other summer toys.
Do they make such a thing that I can wire the whole works
up
...plug in for the winter and walk away til spring?

thanks for any replies....Jim