Battery goosed?

[ghostlymoron]

Tested my boat battery (75ahr) yesterday, it showed 8.6v. Does this mean it's goosed? I'd assumed (hoped) that my 20w solar panel would trickle it over winter despite being in a shady spot. My clever charger wouldn't attempt to charge it and displayed ERR, the non intelligent charger only showed about half an amp even when left on over night. The plates are covered with acid.
My boat has no engine so only lighting and instruments and I have a spare battery off the caravan which I think is ok.

 

[ip485]

What type of battery?

Sadly, with such a low voltage it probably is, but (some) recovery might be possible depending on the type.

 

[RichardS]

Tested my boat battery (75ahr) yesterday, it showed 8.6v. Does this mean it's goosed? I'd assumed (hoped) that my 20w solar panel would trickle it over winter despite being in a shady spot. My clever charger wouldn't attempt to charge it and displayed ERR, the non intelligent charger only showed about half an amp even when left on over night. The plates are covered with acid.
My boat has no engine so only lighting and instruments and I have a spare battery off the caravan which I think is ok.

I would say that 2 cells have gone the way of all flesh.

If you charge it up overnight with the thicko charger and leave it for an few hours and test the voltage and it still says around 8.6V then those 2 cells are never coming back.

Richard

 

[Norman_E]

For now I suggest you swap the batteries. I have one of those cheap 6 and 12 volt chargers sold by Lidl or Aldi that has a mode that will revive a badly discharged battery. Last year I found that the battery on my kit car had completely discharged. To my amazement when I connected it to the charger it started charging, but only reached 7.2 volts when on charge and then dropped back below 6 volts. The penny dropped that the charger was recognising it as a 6 volt battery. At that point I charged it again to 7.2 volts and transferred it to a different small charger that only has a 12 volt mode. The battery was very slowly charged up to full charge, and has been OK since.

EDIT: When trying to revive a badly discharged battery the key is to charge it very slowly. The charger I used has a maximum 3.5 amp charging rate and about 1.8 amps in motorcycle battery mode. the final mode is specifically for battery revival, and I don't know how that works but suspect it provides the charge as a high frequency on-off current.

 

[PaulRainbow]

Considering a new battery is about £60 and the dead one will come to about a tenner in the scrap, i'd just buy a new one.

 

[ghostlymoron]

My clever Aldi charger reputedly has a recondition mode but I've lost the instruction book.

 

[VicS]

My clever Aldi charger reputedly has a recondition mode but I've lost the instruction book.

Lidl make their instruction manuals available via their website. Maybe Aldi do the same.

 

[Norman_E]

My clever Aldi charger reputedly has a recondition mode but I've lost the instruction book.

I think it was the Aldi one that revived my battery. It is the type with a voltage display.

 

[davidmh]

Rainbow .Where do you get £10 for a scrap battery

David Mh

 

[PaulRainbow]

Rainbow .Where do you get £10 for a scrap battery

David Mh

Would you believe it, scrap metal recyclers !

 

[matthewriches]

I bought a few of those just for chucking on my motorbike, van and a friends quad and they're fairly decent things for less than £20 or whatever they were. Not tried to revive a battery with one yet but succeed a few times using a Ctek that I used to keep on my Land Rover. Worth a go otherwise as PR says, just ditch it.

I think it was the Aldi one that revived my battery. It is the type with a voltage display.

 

[wallacebob]

I have "revived" an exhausted battery by connecting with jump leads, a good battery in parallel, then charging with aldi charger on dead one. It fools charger, and gets enough charge into dead one to enable proper charging. Or fit it to your car, and then jump start it. You will soon know if its really nacked.

 

[William_H]

If OP has used a crude battery charger that put in about 1.5 amps overnight or for long period and the voltage remains at around 8 volts then yes battery is "goosed" or even cream crackered. olewill

 

[ex-Gladys]

Several years ago I stupidly left Gladys' domestics on with the Navtex on for 6 weeks. The upshot was 3 brand new AGM's registering 4 volts. An old fashioned (non-smart) charger recovered them, and they survived 8 years. I think that they would have had a longer life without the abuse, but at least I didn't have to replace straight away...

 

[ghostlymoron]

I've now located and read the instructions on line. It appears that the charger should sense if the battery is unusually discharged and commence the 'revive' sequence after a short delay and repeat voltage check. Not sure if I gave it enough time last time I tried so will try again and leave for a bit. If no joy, will hook up to my good battery with jump leads and try fooling charger into starting.
If still no joy old battery goes to the dump.

 

[rotrax]

I suspect the battery is not " Goosed "but ducked-Donald Ducked.............................