battery restoration after going under

[JT!]

bought a boat with 4 less-than-a-year-old batteries, the boat was underwater (seawater) for only a few hours and the batteries all discharged.

I have battery #1 on the charger, checking if it will come back to life.
About to pull the other 3, is there a procedure I should try before charging them?

 

[Grub54891]

Freshwater or salt? I actually don't know if it makes a difference. Start by making sure the levels in them are correct, not to full. Good luck! Never had that happen to me.

 

[JT!]

saltwater.

everything was a write off. got it for pennies on the dollar

every dollar saved restoring it is a win.

 

[alldodge]

Assuming these are lead acid bats.

Take every battery and pour everything out, empty them, then flush with fresh water several times. Once clean and empty, get some battery acid and refill them.

The batteries lead plates should be fine, its just the sulfuric acid is diluted and needs replaced

 

[Bluewater84]

I’ve heard to only use distilled water for this process. You city water may contain contaminants that will hurt the cells

 

[alldodge]

I’ve heard to only use distilled water for this process. You city water may contain contaminants that will hurt the cells

Agree, if we were adding water to an existing battery cell. Need to start fresh and get all the old crud out and its cheaper and easier to use city water to flush and then drain it all back out. Once the sulfuric acid mix is added, then use distilled if any is needed later