Ideal method to store batteries

[iLean]

We have 10 batteries on our 46' Sense and have encountered different views on best way to store them during Michigan's winter months. Any thoughts?

Thanks in advance!

[Greatest Lakes]

For some reason, letting them sit directly on concrete seems to tank them. I've had a fair amount of luck just disconnecting them from each other and from the system after haulout. I leave them in place on the boat over the winter. My dad takes them off and puts them on maintainers over the winter in his heated garage. He loses batteries more frequently than I do and we buy them from the same place. I have been using LiFePo4 batteries for more than a decade for aircraft. I haven't gotten them for the boat yet, but I plan to. Those I store at room temperature. Most batteries lose some oomph while cold, but return to normal with warmer temperatures. Unless you get to -70c you aren't gonna freeze them.

[markrsimon]

I dont have as many, but I label them all so I know they go back in the same spot. Then I keep them in the basement on a marine charger (lower capacity, but same style and # of banks). Basically the batteries dont know they are out of the boat. The charger floats and exercises the batteries once a month. I check fluid levels half way through the winter and again in the spring. If you dont have a spare charger - then manually connecting a suitable charger to each battery every other month to top them off works well. Assuming your also talking about lead acid.

[Nicholson58]

We stored Lifelines in Michigan for several years. I disconnect the negative, that’s all. I check up every four weeks or after snow to keep the cover clear. Whenever I’m there I reconnect and run the charger for an hour or so.

Don’t forget to put -90 nontoxic antifreeze in the bilge.

[pitlaw]

This applies to both AGM and wet cell battery types. Make sure they are fully charged. Disconnect them from the load, that is the + and - which go to the boat.
Leave them on the boat. Assuming all are good and without a bad cell there is no need to disconnect them from one another. And there is no need for a trickle charger. AGMs have a very slow discharge rate,wet slightly higher. This assumes you have them disconnected for the winter. . See https://marinehowto.com/ And his article on winter storage for my source.

[Orion Jim]

Originally Posted by pitlaw

This applies to both AGM and wet cell battery types. Make sure they are fully charged. Disconnect them from the load, that is the + and - which go to the boat.
Leave them on the boat. Assuming all are good and without a bad cell there is no need to disconnect them from one another. And there is no need for a trickle charger. AGMs have a very slow discharge rate,wet slightly higher. This assumes you have them disconnected for the winter. . See https://marinehowto.com/ And his article on winter storage for my source.

Exactly what I do with my AGM’s. Healthy batteries require no mid-winter charge.

[billdre]

Originally Posted by Orion Jim

Exactly what I do with my AGM’s. Healthy batteries require no mid-winter charge.

+1 Have the same Lifeline AGM's for 7 years. Fully charge at haul out, recharge in Spring. I'm on Buzzard's Bay, Massachusetts. Winter is plenty cold. Not a problem.

[My Wind Lass]

I would leave mine in all winter connected to my solar panel (in Montreal). They always stayed fully charged. I went every other month to check if there was snow on the panel and clear it if there was but I kept the panel at about a 40 degree angle facing the lower sun arc and the panel did not usually accumulate much snow. Only when it was very wet snow.