batteries unused 8 years good ?

[arch007]

Boat was on the hard 8 years.

Any chance batteries are still good ? Wet cell.

Should i junk them ?

[Island Time O25]

When I got my first boat it had onboard 2 batteries - one about 4 years old and the other about 6. The boat was on the hard at least 4 or 5 years before me and 1 more year before I launched her. By the launch time the then 7 year old one could not be revived and was used as a return core. But the then 5 year old was OK and lasted about 3 more seasons. And it only went dead due to a stuck bilge pump.

I've had all kinds of different working lives for the batteries - no rhyme or reason. Same brands would last 2 and 5-6 years respectively. I tend to follow the philosophy of getting 2-3 years out of $60-80 batteries than 5-7 years out of $200 ones. With the often added bonus of such cheap batteries lasting 5 years or longer.

[roverhi]

Batteries that have not been kept charged while in storage will almost guaranteed to be junk. If the batteries have been regularly charged, you may get lucky but I've never gotten more than 5 years out of lead acid batteries and usually less.

[four winds]

In a lifetime of doing my own maintenance it seems the most common time for battery failure is in the late fall or early spring season of year five.

With eight years sitting with no attention I think there is little hope they can be revived. But I'm stubborn so would probably try using a 2 amp trickle charge for a couple of days and see if the voltage starts to rise.

Self discharge probably killed them and the case is full of sulfate in the bottom.

[StuM]

Originally Posted by four winds

Self discharge probably killed them and the case is full of sulfate in the bottom.

Spot on!

[tuffr2]

As I understand there are groups 24, 27, and 29. The batteries get better as you move up in group.
If the batteries are the usual group 24 I would replace them with group 27 or 29. Right or wrong I also understand that a group 27, 29 are much more robust are are easier to bring back to life.

[Cheechako]

They are junk.

[kmacdonald]

Charge and equalize them. Should be good for another 8 years if you cycle to 80% DOD.

[StuM]

Originally Posted by kmacdonald

Charge and equalize them. Should be good for another 8 years if you cycle to 80% DOD.

OK, I think you've just confirmed my theory.
That one is a bit blatant for you.

My hat is off to you. You really are in a class of your own.

Sorry it took me so long to catch on.

[kmacdonald]

Just checking.