lead acid battery - charging from dead

[bigegg]

i have an old (new) car battery - never been on a car, but been sat under my bench for a couple of years.
i want to see if i can get it wirking, but i only have a "smart" charger.

if i connect it to a 14v, 0.5a(say) dc supply, will i be able to get enough charge into it to get the smart charger to work?
its a variable, constant current, bench top power supply, so can be set to output anything from 5-30v, 0-5a.

it'll be done in no. 3 hot work shed: away from anything that could be damaged by an exploding battery! (including me)
i plan to give it an hour, test on the smart charger.
repeat up to 5 times.

 

[ajlelectronics]

Smart charger will not do anything if the terminal Voltage is low. Kick it first with a proper charger or another battery and jump leads. Then allow the smart charger to take over.

 

[zzr1200]

Connect another battery in parallel then charge the pair together if your lucky the dead one might pick up after a couple of days on charge...

 

[bigegg]

Smart charger will not do anything if the terminal Voltage is low. Kick it first with a proper charger or another battery and jump leads. Then allow the smart charger to take over.

basically what i planned - but using a psu rather than "proper charger" or other battery.

 

[bigegg]

Connect another battery in parallel then charge the pair together if your lucky the dead one might pick up after a couple of days on charge...

i only have the one battery...

 

[zzr1200]

i only have the one battery...

Beg steal or borrow...

I probably have a spare one, you could have.

 

[bigegg]

long term plan is to put a solar panel on tbe roof, and use the car battery to run the diesel shop heater + one emergency 12v light so in the event of having the power go off in the shed the heater shuts down safely, and i can see to get out.

 

[bigegg]

Beg steal or borrow...

I probably have a spare one, you could have.

lol.
thx.

it might be easier just to beg/steal/borrow a known working one and dispose of this one...

 

[ajlelectronics]

Your PSU will be fine to kick it.

 

[bigegg]

never mind.
i've just looked where the battery was, and it's gone.

i have a vague recollection of throwing it on the scrap run i did last year.

 

[Alan Reynolds]

Lead acid batteries left in a discharged state rarely revive enough to be of any use. They like to be 'exercised' otherwise they sulphate up. That's why you don't buy from the little corner motor factor as their turnover can be slow. Keep a battery 'interested' by putting it on charge and use a plug in timer to just trickle it once a day for 10 mins. Keep it off the concrete which can be damp in winter.

 

[Eric the chicken]

I managed to revive a lead acid battery back in the 80's. It had been left unused on Land Rover for 6 months and parked in the open. I alternately charged it, with a standard battery charger and then discharged it by connecting a head lamp bulb. When fitted back on the LR it lasted another two years.

 

[jerrytug]

I have a mate who reckoned you can blast the deposits from the plates of dead, unchargeable batteries, by briefly touching mains 240 AC on the terminals. A bit of a flash and don't try this at home etc, but I did witness it work at least once. Before the days of so-called smart chargers.

 

[premmington]

Lead acid batteries left in a discharged state rarely revive enough to be of any use. They like to be 'exercised' otherwise they sulphate up. That's why you don't buy from the little corner motor factor as their turnover can be slow. Keep a battery 'interested' by putting it on charge and use a plug in timer to just trickle it once a day for 10 mins. Keep it off the concrete which can be damp in winter.

+1 for the above

 

[premmington]

I have a mate who reckoned you can blast the deposits from the plates of dead, unchargeable batteries, by briefly touching mains 240 AC on the terminals. A bit of a flash and don't try this at home etc, but I did witness it work at least once. Before the days of so-called smart chargers.

I have a Bosch C7 battery charger that reckons it does this by "pulse charging" - to revive them!

I have yet to see it work in practice - I have tried it on a few batteries.

 

[Pigeon_Droppings2]

If they are too drained I just chuck them...1 exploding battery was 1 too many for me!

Just glad I was nowhere near it when it went off....blast zone was about 6 foot radius!

It had actually recovered (or so I thought)....and was just on a trickle charge when it went off.

 

[premmington]

I have a dip in the concrete floor at my workshop where over the years - batteries have "over charged" and eaten the floor away.

Price of batteries has gone up a lot this year - even thou we are still in the summer months (historically batteries cost more in the winter).

 

[Jetex]

If you have a variable power supply why bother with the smart charger at all? If the battery is not damaged then you can just charge it up with setting 14.6V If your power supply is self limiting then it should take the full 5A if the battery is discharged. Give it a good 10 hours charge. If when set to 14.6v the current does not max out to 5A then the battery may have some damage but it may also recover.

 

[bigegg]

If you have a variable power supply why bother with the smart charger at all? If the battery is not damaged then you can just charge it up with setting 14.6V If your power supply is self limiting then it should take the full 5A if the battery is discharged. Give it a good 10 hours charge. If when set to 14.6v the current does not max out to 5A then the battery may have some damage but it may also recover.

thanks for that - learnt something new.

 

[Jetex]

A car alternator charging system will usually regulate the charging voltage to 14.6V and they can put out a current of 40A or more so the normal charging in a car is far harsher than charging with your variable power supply