Will I damage my batteries or electrical system if I plug my shore power in for winter storage?

I usually plug it in and set the oven timer on while I'm home from time to time. Had a bad experience with a charger and simply do not trust them.

if you have a good charger that test batteries and charges accordingly, yes plug it in and let it "float" the batteries..Rob

I wouldn't leave the charger on all winter.

I keep my boats in heated storage, but what I do is put the boat away with fully charged batteries and disconnect them from the boat. They are usually nearly fully charged in the spring. This may have nothing to do with it, but my friend in the same storage unit puts his on a cgeap battery tender and his batteries wound up shot last year. Mine are outlasting his by far.

I will plug it in for a day or two every other month. Thanks for the replies.

The experience I had was while working in the bilge the onboard charger was on. Started smelling burning plastic, turned around as smoke billowed from the charger. Good thing I was there. During the winter months I plug it in for several hours keeping a watchful eye.

There are trickle chargers made for this purpose. They put out about 1/2 of an amp continuously. They are safe and won't over charge your battery. I would not use the main battery charger all winter.