Battery protection

Discussion in 'General Electronics Chat' started by superway, Feb 8, 2012.

  1. superway

    Thread Starter Active Member

    Oct 19, 2009
    128
    0
    Hi,

    Can anyone help me this question?

    An adjustabel DC power supply ( Lamda) connects in parallel with 4 batteries which connect in series 12V-24-36V-48V to test the products.
    If we test the product with 12Vdc, we have to adjust the DC power supply to 12V, assuming the battery cable is connected to 12v battery, or test the product with 36V we have to adjust DC supply to 36v and also switch the battery cable to 36vdc battery. Sometimes testers adjust the DC power supply to 36vdc or 48Vdc and they forgot to disconnect the battery cable on 12vdc battery or 24Vdc, then battery blew up. My question is there any protection device or any sugesstion how to protect the batteries in this case?

    Thanks in advance!

    CN
     
  2. nsaspook

    AAC Fanatic!

    Aug 27, 2009
    2,908
    2,168
    Proper training, power supply current limiting , correct fusing and beatings. :D
     
  3. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Whats the point of the batteries??? Are they part of the unit under test (UUT)?
     
  4. superway

    Thread Starter Active Member

    Oct 19, 2009
    128
    0
    Yes, they are part of UUT.

    As nsaspook mentioned current limit on DC supply, do we have to set current limit on DC suply everytime we switch to different battery voltage?

    Thanks
     
  5. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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    If you have no positive interlocks for wrong voltage then you have to at least set limits that won't cause it to explode (quickly) when the wrong voltage is used. A look at human factors might help. Something like a simple latching relay where you must press a button to apply voltage with a set of color coded lights next to it indicating voltage on the battery and voltage on the charger. If the light codes match then it's safe to press the button.
     
  6. superway

    Thread Starter Active Member

    Oct 19, 2009
    128
    0
    Thanks nsaspook. What is the positive interlock device? i have never seen it. Can we install an in-ine fuse to battery string cable in case if over voltage applying to battery, the fuse is disconnected?
    Thanks
     
  7. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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    Positive/passive interlocks.
    An example for your problem would be different size or type connectors at each point of a different voltage with dedicated chargers for each voltage that can only mate to a same type connector.

    Your fuse is to stop things from blowing up, it won't fix your root problem.
     
    Last edited: Feb 8, 2012
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