I messed up, batteries dry

[hd002e]

When I purchased these sportsman 90A deep cycle batteries, I failed to check if they needed any servicing and figured that they were sealed. I use 2 x 90A on my boat for the house and have a 400W solar system hookedup to them.

Fast forward 2 years in the Mediterranean sun and absolutely no maintenance later, two days ago I realized how badly I messed up. My solar charge controller turned off and I decidedto take the batteries out to check them. They are pretty light! All the liquid inside is gone!

Before I take it to a battery shop, wanted to get opinions here. Are they doorstops or salvageable? What should be my decision criteria?

[hellosailor]

Usually worth $5 each as a "core charge" or return credit where you buy the new ones.

[MikeFergie]

Fill them up with sulphuric acid charge them and then do a load test ! Miracles sometimes exist

[john61ct]

A miracle would only delay the inevitable, replace.

[Sailmonkey]

Originally Posted by MikeFergie

Fill them up with sulphuric acid charge them and then do a load test ! Miracles sometimes exist

The acid is still in the batteries. And adding more won’t help. Batteries are toast.

[thinwater]

I wouldn't have pondered that for 1 minute. Replace.


A little low is one thing. Didn't check for two years, bone dry, and you're cruising? Replace at first marina.


And put a watering kit on the next set.

[OS2Dude]

Caveat: We are on a lake, not cruising the blue.

When we bought our current boat the two batteries were VERY low on water. (Didn't turn them upside down to see, but could not detect water in most cells thru the ports.) They still could start the engine (Not sure how), so we filled them up with distilled water and let them charge for a while. Used them for another year before replacing them with sealed AGM batteries.

[Calif.Ted]

I've added water or battery acid in the past and while you may be able to get them to accept a charge they won't hold it long and complete failure is eminent.

[Scout 30]

This thread should really be about what's the best thing to replace them with.

[BSMS]

Replace them with firefly batteries
There costly but worth it

[P3sailor]

Just replace them, once dry, they're doomed to fail and most likely when you need them the most.

[motion30]

Dump some water in them and charge them you have nothing to lose

[S/V Illusion]

Originally Posted by hd002e

When I purchased these sportsman 90A deep cycle batteries, I failed to check if they needed any servicing and figured that they were sealed. I use 2 x 90A on my boat for the house and have a 400W solar system hookedup to them.

Fast forward 2 years in the Mediterranean sun and absolutely no maintenance later, two days ago I realized how badly I messed up. My solar charge controller turned off and I decidedto take the batteries out to check them. They are pretty light! All the liquid inside is gone!

Before I take it to a battery shop, wanted to get opinions here. Are they doorstops or salvageable? What should be my decision criteria?

At best, their capacity would be reduced to the point of unreliability. A load test will show how badly. People guessing here won't...

[Zil]

Don't mess with them. Adding acid is way wrong! Adding water and trying to charge could cause a very bad reaction. An eye or two is something to lose.
I'm sure you can find some batteries with more amp hour capacity and be very happy.
If you want maintenance-free chose AGM, or more money, Gel.

[Cadence]

I believe you should hunt down the cause prior to spending new money after bad.