Page 1 of 2 12 LastLast
Results 1 to 10 of 19
  1. #1
    Bronze
    Join Date
    Mar 2007
    Posts
    1,547
    Post Thanks / Like

    Default Battery Gurus - Question

    A set of 12 batteries for 24 Volt system have been let run dry but appear to be fully charged giving a reading of 6.4 volts. But they have no capacity.

    What liquid should be used to top them up? They are not very old so should have some life left.

    Sulfuric Acid 1,27 Specific Gravity

    Distilled Water for Batteries?

    Olly

  2. #2
    Silver
    Join Date
    Jan 2013
    Posts
    3,780
    Post Thanks / Like

    Default

    I am no specialist.

    I was told to fill up one time with agua distillada, amd the next with "solution".
    And also not to use " solution" when they are dry as it corrodes the "plates " ......
    Just what my electrician guy told me....

  3. #3
    Regular
    Join Date
    Dec 2013
    Posts
    177
    Post Thanks / Like

    Default

    Not relevant, deleted.
    Last edited by DR1Admin; 06-11-2015 at 04:56 PM.

  4. #4
    Platinum
    Join Date
    Feb 2006
    Posts
    12,296
    Post Thanks / Like

    Default

    appear fully charged?
    do you mean you connect them to a charger which says "full"? you don't do that with the batteries still dry, as that would give 'em just the rest tehn.
    fill 'em with distilled water first and connect them to a charger. once fully loaded, use them with something that does not discharge them too heavy/not at their crank limits.
    then take 1/3 of the water out and replace it with "solution". charge them again and once the charger shows "full", check what power they show.
    6.4 Volts on a "charged" 12 Volts battery means mostly "dead". you can recover them as described above for minor use, but they will never again come back to their original powers/never again deliver the originally meant for Amperes.
    for what do you want to use those batteries?

    Mike

  5. #5
    Gold
    Join Date
    Apr 2014
    Posts
    6,191
    Post Thanks / Like

    Default

    Batteries have a finite limit to how many times they can be discharged/charged. If a battrery is allowed to run dry, the useful life of that battery is over as it will never again function as well as it would have or for as long.

    Batteries connected to inversors are receiving a trickle charge all the time. It is really important to check fluid levels regularly. I check mine every two weeks, others I know check once a month.

    As to your question, I would say the chances of you being happy with the performance of a revived set of batteries is pretty slim. Since we are talking about 12 batteries, I'm assuming they are connected to a home power system. You may be able to get them to charge to 6V but they won't sustain that voltage for very long when placed under load.

    A solution of acid and distilled water in a ratio recommended by the manufacturer is what I'd use in your situation if buying new batteries (for peace of mind) is not in the cards.

  6. Likes zoomzx11 liked this post
  7. #6
    Platinum
    Join Date
    Feb 2006
    Posts
    12,296
    Post Thanks / Like

    Default

    Olly,
    sorry, i was reading your OP wrong.
    i understood it as 2x 12 volt batteries for a 24V system, hence i wrote that those 6 volts sound very dead.
    i just now realize that you wrote " 12 Batteries", lol. sorry, didn't want to misslead

    Mike

  8. #7
    Regular
    Join Date
    Aug 2010
    Posts
    458
    Post Thanks / Like

    Default

    distilled water works but if you can get some battery acid that would be great. find another battery and add the acid but be careful to not to corrode your self

  9. #8
    Platinum
    Join Date
    Jul 2004
    Posts
    28,263
    Post Thanks / Like

    Default

    One should never add additional battery acid to a battery that was already in use, unless that acid was somehow spilled from the battery and then it can be replaced by more acid. Distilled water only.
    Some claim EDTA can restore a battery, but I have had no luck using it and cannot recommend it from my personal experience.

    In the case of the OP, the batteries may charge fully on an inverter after being topped off with distilled water, but the capacity may be so low as to render them useless for their intended purpose.

  10. Likes N/A liked this post
  11. #9
    Platinum
    Join Date
    Jul 2004
    Posts
    28,263
    Post Thanks / Like

    Default

    Quote Originally Posted by bizzyboneizo View Post
    distilled water works but if you can get some battery acid that would be great. find another battery and add the acid but be careful to not to corrode your self
    Battery acid would not be "great".

    When Should I Add Extra Sulfuric Acid to my Battery?

    When you see your battery acid level begin to drop, you may wonder when and if it is appropriate to add acid, or just water.

    We recommend that unless a battery was tipped over and all the acid spilled out, that you add only distilled water. Think of it like this: If you were to fill a pot up with salt water, and put it on your stove to boil, what happens? All the water will boil off, and you will be left with only salt. To re-create the original salt water mixture, you simply add straight water, because all the original salt is still in the pan, waiting to be re-suspended in the water. Batteries are the same way. All the chemical needed to make sulfuric acid is still in the battery, it is just the water that is gone. If you add more acid, you will be changing the chemical makeup of the battery which can lead to an incorrect sulfuric content.

    http://www.batterystuff.com/kb/frequ...y-battery.html

  12. Likes N/A, Criss Colon, Fredo liked this post
  13. #10
    Gold
    Join Date
    Jan 2006
    Posts
    6,768
    Post Thanks / Like

    Default

    Its over for those batteries. You can play around adding all sorts of acids, water, battery viagara etc. but the fat lady is singing.
    Been there done that. For the future. Never ever let them get dry. Its a death sentence.

  14. Likes windeguy, N/A, Criss Colon liked this post
Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •