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.
This probably also explains the corrosion I’ve seen on one of the ferrule crimps.