I have researched some older threads but wanted to ask again. Does anyone leave their battery charger on while in winter storage? Or should I maybe just charge once a month for a few hours or days? My boat is a 00 Model Top Gun. Thanks

We use a simple trickle charger from Harbor Frieght.

If the batteries are in a location where they can freeze it is best to remove them and store them inside; charge them fully prior to storage and they should be fine. You can always throw the charger on once a month or so to make sure they stay charged and don't store them directly on a concrete floor.

I leave my charger in the ON position and then plug it up once a month or so for a day or two....

Just get a Battery Tender they make a few models now that can charge and cycle the batteries throughout the winte for you. I have 1 on my 99' WS6 T/A still with the original battery in it. I think I paid 40.00 for it 10 yrs ago well worth it IMO. and you don't have to worry about plugging and unplugging if you forget like with a regular charger.

If you fully charge them before storing them youll be fine in the spring.
I have mine sitting in the basement on a 2x6 so they are not on the concrete.
In the spring I would just throw them on a charger before I put them in the boat just to make sure.
I have Gel Marine Batteries.

I just plug the boat in and let the battery charger do it's thing. I assume you have shorepower and a fully automatic battery charger in the boat? That's what they're designed to do!

I do the same. My experience is the trickle charger bakes the battery over a long period. Usually get three to four seasons out of mine.

I've always done the trickle charger on all my boats. Just replaced the batteries in the sea ray, they lasted 5 years with the trickle charger.

That's what I do. Shut off the batteries but leave the charger on and the shore power plugged in. Works great.