Battery fried?

[srah1953]

Hi. I was ill for a couple of years and the boat was on the hard plugged into the mains, untouched by human hand, keeping the batteries charged, etc. When I recovered and looked at the boat, one of the (wet cell) service batteries had some caking around the positive battery post. After some five days off charge, the battery is showing around 13V. Does this mean that the battery should be okay or does it need to be replaced?
Thanks

 

[lw395]

I'd suggest testing the batteries like you're going to use them.
Run a load like a car headlight bulb for a couple of hours and see how the voltage drops.
13V sounds encouraging, but I've seen batteries hold a voltage but have lost a lot of capacity.

 

[duncan99210]

Battery showing 13v after a period off charge means it’s should be fine.

 

[moomba]

Note that if one cell in the battery is gone, it will still show a full charge if you are testing with voltage meter, had the same issues when I got mine looked at professionally , they took a drop from each cell and put it in some eye glass contraption and they showed me the outcome and one cell was defiantly dead , but the battery was still showing 13.5 volts.
He could not give me an explanation to this though.

 

[srah1953]

Many thanks for the replies