should refilling a batt with water, bring it back to life?

Phil2008

Phil2008

Phil2008

Soldato
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17 Dec 2004
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It started in the summer, sometimes the batt would be dead and would have to jump start the car. But this last month with the cold days, the car would have to be jump started every morning, but if you give it 10-15mins with the engine running, it starts ok after that, a bit like when the engine has warmed up the batt its got more life in it.

A few days ago we checked to see how much water was in it, and there was none, so today we bought a bottle of water and the batt used all of it.. now its on charged,, Hows the chances of the batt comming back to life? We charged it a few weeks ago but it made no diff, but it didnt have any water in it then.

Also its being recharged in the car so it will be cold, cos ppl cant be bothered to take it out and bring it indoors... and I said to then it wont recharge properly outside, but hey.:(
 
I love how people post questions to OCUK as if OCUK is some 'all-knowing entity' that can answer any and all questions, on any subject matter, with as little information as possible, where 9/10 times the collective answer is 'Don't know. Do it and tell us whether you are dead. Or if it worked. Or whether mince and jam tastes nice, or whatever the subject of the question is'


:)
 
phew now thats a question, it depends entirely, if the battery has been deeply discharged then sulphation will occur on the plates which prevents charge from being held in the battery, also lead acid car batterys are not designed to be deep cycles and have a very limited life in regards to deep cycles, so when the battery is flat its damaging it and reducing its charge holding capacity.

The water thing is another issue and lack of water wont help either, your plates could have buckled because of the lack of water shorting out a cell, (it would reduce the voltage and charge holding capacity) in reality if your battery is doing what its doing its probably just best to buy a new one.

You can get chargers or infact make a simple piece of logic to help revive a sulphated battery, they effectively use high current pulses to loosen the sulphation on the plates but results are pretty varied and in reality its more trouble than its worth unlesss you know what your doing or have the parts handy!

so in other words you probably need a new battery!

you could also try leaving the battery on charge for a long period of time as well, but I would just get a new battery
 
Its worked for me on two occassions, both had a few dry cells where the plates were not fully covered (seems to be the end ones typically). Refilling with deionised water and then giving a good charge overnight revived them from the dead :)
 
Once you've topped it up, and charged it, you could test each individual cell with a hydrometer~available at Halfords etc. Sometimes one cell will go down, and wont hold a charge, leaving you with @10v or so. But a suspect battery will be exposed in a cold snap. I'd change it.
 
whitecrook said:
I love how people post questions to OCUK as if OCUK is some 'all-knowing entity' that can answer any and all questions, on any subject matter, with as little information as possible, where 9/10 times the collective answer is 'Don't know. Do it and tell us whether you are dead. Or if it worked. Or whether mince and jam tastes nice, or whatever the subject of the question is'


:)
Click to expand...

You missed THE most important question..

Was the pasty tasty!
 
As the cells contain sulphuric acid and not water, water will not cure a dry cell, you will need to top up with the correct sulphuric acid. Topping up with water will only work where there has been evaporation. In other circumstances you will be diluting the acid and effectively lowering the batteries capacity.
 
I thought batteries were sealed these days. I can't remember the last time I saw someone top up a battery :)

When in doubt pop down to your local scrappy. Ask them for a 2nd hand Bosch Silver Cell battery, they usually come on vans etc. I picked one up for £10 3 years ago, still going strong.
 
Stop being a tight git and get a new one, you can forget about it for 10 years then.

If you repair it now you'll be worrying next year and may have to do the same again and you'll end up getting a new battery anyway.
 
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