In 2023, I replaced the starter battery for Blue Opal with a smaller 80Ah one, as the 105Ah was having problems. Said problems included finding out that there was acid on the bottom of the battery when I placed it on the mat that protects the top of the companionway. What I didn’t twig at the time is that this probably meant I had acid below the wooden boards that the battery sat on.
A week or two ago, I lifted up the solar charger and noticed that the bottom metal was showing signs of corrosion. I’ve had that charger for barely 6 months, so there’s no way it should be showing signs of corrosion in a protected compartment. Yesterday, I took up the boards, and there was liquid below them.
I tossed some baking soda into the liquid, and it was an instantaneous fizz. Quite a vigorous fizz too. So, water, more baking soda, and then baking powder when I ran out of baking soda. I’ll go back today with more baking soda, and apply more water and wash the whole thing down several times.
This probably also explains the corrosion I’ve seen on one of the ferrule crimps.