Charging lead acid battery bank

Discussion in 'General Electronics Chat' started by edwilliams, May 16, 2012.

  1. edwilliams

    Thread Starter New Member

    May 16, 2012
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    I have 6 12 volt car batteries hook up to produce 72v. I have seen chargers that can be connected to each battery and charged at 12v each while the batteries are still series and using the 72v from them. But they are expensive. What kind of circuit would it take to do this from 12v to charge the batteries while still using the 72v.
    Thanks Ed
     
  2. #12

    Expert

    Nov 30, 2010
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    What it takes is six (6) seperate transformer windings driving six (6) seperate brain circuits to keep the batteries from connecting to each other through the chargers. The cheap way might be to buy 6 cheap 12V chargers and make sure they do not have their charging leads connected to the metal case or earth ground (in the power cord).

    Is that what you needed?
     
  3. edwilliams

    Thread Starter New Member

    May 16, 2012
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    How are these new charges setup to do this. If I would use diodes to each lead going to battery to charge would this work or is there circuit I could build other than having 6 transfomers.
    Thanks Ed
     
  4. #12

    Expert

    Nov 30, 2010
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    6 different chargers would be "set up" by connecting one to each battery. Diodes will not fix the isolation problem. A circuit to do this would be a 72 volt battery charger, but that is exactly what you were trying to avoid in the first question.
     
  5. edwilliams

    Thread Starter New Member

    May 16, 2012
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    I have altenator that has 12v dc is the anyway to use that source to do this.
     
  6. #12

    Expert

    Nov 30, 2010
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    One 12 volt alternator will charge one battery.
     
  7. edwilliams

    Thread Starter New Member

    May 16, 2012
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    If I would use the stator wires wired to 3phase bridges. I will work out the rest of circuit. Would that give me isolation?
    Thanks Ed
     
  8. takao21203

    Distinguished Member

    Apr 28, 2012
    3,577
    463
    Is this battery bank indoors? Or in the garage/workshop maybe?
    Fire precautions/risk?

    You can use 6 relays and only charge one battery a time, for some minutes.

    If you don't take much current from the battery bank, this won't be an issue.

    Isn't there another solution you can use? Why 6 batteries?
     
  9. crutschow

    Expert

    Mar 14, 2008
    13,001
    3,229
    Nope, still no isolation. The only way to achieve isolation is to have six separate transformers (or alternators) or one transformer with six separate output windings. :(
     
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