Winter Storage + Batteries?

Sep 8, 2025
75
Bayfield 36 Lewisporte
Hi,
New boat (to me). It has 3 x 100Ahr Lead Acid Batteries. Its using a 100W solar panel to charge them. The boat is now on the hard and eventually that solar panel will be covered in snow. Should I just leave it as is or is it better to disconnect the battery leads?
 
Sep 25, 2008
7,569
Alden 50 Sarasota, Florida
If the panels will “eventually be covered in snow”, i Infer that means the boat isn’t covered during winter.

Snow will melt. Unless the boat is ‘dry’, water will get into the bilge. If your bilge pump doesn’t have power, it will obviously freeze. Not a good recipe for anything. Either cover the boat or leave a battery to power the pump. As the self-discharge of lead acid batteries is directly proportional to temperature, it too will be low during winter.
 
Sep 8, 2025
75
Bayfield 36 Lewisporte
If the panels will “eventually be covered in snow”, i Infer that means the boat isn’t covered during winter.

Snow will melt. Unless the boat is ‘dry’, water will get into the bilge. If your bilge pump doesn’t have power, it will obviously freeze. Not a good recipe for anything. Either cover the boat or leave a battery to power the pump. As the self-discharge of lead acid batteries is directly proportional to temperature, it too will be low during winter.
Yes, unfortunately it is not covered. I do worry about ice in the bilge. I guess on the plus side the winters aren't to harsh here.
 
Jan 11, 2014
13,298
Sabre 362 113 Fair Haven, NY
If the batteries are fully charged, just disconnect the negative cable and call it a day. Flooded batteries need to be fully charged and have enough water.

Water in the bilge can be an issue, especially with keel stepped masts when the mast is left up. If the bilge pump is left on and the water freezes it can render the pump inoperable, possibly causing it to seize. A common approach to the water issue is the installation of a garboard drain plug. This is a bronze plug and fitting installed in the lowest part of the bilge, when opened water can drain out. Just remember to put the plug back in before launch.
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,644
CAL 35 Cruiser #21 moored EVERETT WA
This might be a good thread to review.



 
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