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Reverse Osmosis water in battery

Is it OK to add reverse osmosis water instead of distilled?

I believe RO leaves behind slight amounts of minerals, but distilled might leave behind a few chemicals too, like chlorine.

So is it 6/half a dozen? Or is distilled the only way to go?

Also, is it possible to revive a dead battery by topping it off with water and slowly charging it with a charger?




  • edited May 2010
    Distilled water is the way to go. After all, it isn't that expensive.

    If the battery is truly dead, and water isn't the issue, adding more water won't save it.
  • edited May 2010
    Distilled is the right water for a battery.
    "dead" means different things. If a battery is discharged say by leaving the lights on all night, it is called by most folks "dead", but it will usually take a charge and soon be good again. If the fluid in the battery is low, which happens over time, the battery will not hold a charge as well as it should, nor deliver the current you need. In that case, topping up the fluid with distilled water to the line will be good for your battery, you should check the level every 6 months or so to insure long battery life. If the cells have flake from the plates accumulated in the bottom, they will short out and the battery is effectively at the end of its first life. A battery shop can remove the plates, clean the cells and restore the battery for a few more years of life, this is a sort of battery ressurection. If the specific gravity of the fluid, the acidity is too delute, the fluid can be changed out to bring the battery back as well. so you see the term dead battery covers a lot of ground.
  • edited May 2010
    Thanks i9, very helpful. I believe the latter is the issue. If the charge doesn't take I'm just going get a new battery. Although... how safe is it to change the fluid out for a do-it-yourselfer? And what is the cost of the fluid?
  • edited May 2010
    Don't change out the fluid (a sulfuric acid solution). If the battery won't take a charge, get a new one.
  • edited May 2010
    The water may not matter much. If your battery is not old and I don't know enough to say what is old for various lead acid battery types, your battery may be sulfated. Google "Sulfated battery" and do some reading. I have a problem battery too and don't know enough at this point to advise a way to overcome sulfation.

    Here is some reading for you.
  • edited May 2010
    Reverse osmosis water is fine. Well water with lots of lime in it is not.

    If the dead battery is still good, it will be revived. If it won't take a charge, you will know what the next step is. The battery does the decision making in any case.

    The distilled won't break the budget, so why use anything else?
  • edited May 2010
    RO water is fine..Automotive batteries don't last long enough or use enough water to make any difference..

    Few "dead batteries" will revive..You can TRY to charge them, try 5 amps for 10 hours..Then perform a load test. If the voltage drops below ten and does not instantly recover to above 12, the battery is junk..
  • edited May 2010
    you can use clean rainwater too-Kevin
  • edited May 2010
    You can also use clean rainwater-kevin(got a double post sorry)
  • edited May 2010

    RO water is just highly filtered water. It's about 98% pure water. Distilled water is 99% pure water. Distilled water is created by actually boiling water...then funneling the steam through pipes into another container where there's nothing left but pure water. All the other contaminates were left behind because they were too heavy.
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