Parallel Input and Series output from a Battery

Discussion in 'Power Electronics' started by Anant Singh, Jul 7, 2016.

  1. Anant Singh

    Thread Starter New Member

    Jul 7, 2016
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    0
    Hello,
    I'm struggling with a problem please help me out of this..

    I have four 3.7 volt Li-ion Cells and want to charge them in parallel (For my convenience) and take output from them in series.
    Can anyone suggest a circuit.
    It will be good if a circuit can do both simultaneously but it is not necessary
     
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,762
    924
    A parallel AND series arrangement cannot be done
    while charging and working a load.
    No circuit can accomplish that feat.
     
  3. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    With relays or medium-power transistors you can reconfigure the batteries for parallel charging or series discharging and hop back and forth between the two, but as mentioned you cannot have both configurations simultaneously. To do this with relays you would need two 3PDT relays operated together as a single 6PDT relay.

    ak
     
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  4. BobTPH

    Active Member

    Jun 5, 2013
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    I disagree. It can be done with 4 isolated supplies. Although it might be questionable to call that parallel.

    Bob
     
  5. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    I did not say that my suggestion was the only thing that would work. Of course there are configurations other than the one I described. However, I think one supply, four charge controllers, and the relays or transistors will cost less than 4 smaller supplies and the same 4 charge controllers. Plus, we don't know if the power source for charging is AC, DC, or non-isolated DC that shares GND with the system power output. The relay configuration doesn't care.

    ak
     
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  6. Anant Singh

    Thread Starter New Member

    Jul 7, 2016
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    Thank you guys ..
     
  7. ScottWang

    Moderator

    Aug 23, 2012
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    Anant Singh likes this.
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