Battery Woes

[emandvee44]

When lockdown occurred here in Spain, we left the boat in rather a hurry and went home. Returning yesterday I found the house (3x 140Ah) bank totally flat, ‘0’ volts showing on the meter. I had left the instruments switched on and the AIS running! (it had stopped transmitting after a month so I had an inkling as to what the problem was)

The solar panels had not been able to keep up with the demand and the charge controller auto cut out had kicked in when the voltage fell below the set point.

The battery cells (lead acid) are all dry, at least at the top. I re-filled the batteries but the solar system will not charge them.

Are the batteries a write off? Is it worth connecting shore power and thus try to charge through the smart charger?

Ready for a painful answer.
p.s. I should have mentioned that the batteries are 2 years old.
M.

 

[pvb]

Always worth trying the mains charger.

 

[davidej]

I don't know about spain but here I would charge them first on a mains charger, then take them to a battery specialist who has a sophisticated instrument for testing their condition.

Though they are probably knackered if they have been left dead flat for some weeks

 

[starfire]

Worth trying the mains charger, but, be prepared to replace.

Always worth having someone keeping an eye on the boat.

Guess what my business is

 

[vas]

I'd try a smart charger, one by one first!
if you have one with a recondition function, that's what you want. See if they charge, see, if they hold charge and then decide.
mind some chargers wont even fire up if they don't "see" certain volts on the battery, hence one by one on a smart charger. I have a 10A victron which managed to revive a boat and a car battery so far...

cheers

V.

 

[Skylark]

.........Returning yesterday I found the house (3x 140Ah) bank totally flat, ‘0’ volts showing on the meter. I had left the instruments switched on and the AIS running! (it had stopped transmitting after a month so I had an inkling as to what the problem was)

Not a chance, don’t bother trying to give yourself false hope. Bite the bullet, replace them and put it down to experience.

 

[[70521]]

You must have been in a hurry not to switch off the master switch!