Help needed to design an Ultra Fast Charger with DC input

Discussion in 'The Projects Forum' started by hadigan, Jun 6, 2012.

  1. hadigan

    Thread Starter New Member

    Nov 8, 2011
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    The goal of this project is to charge a 36V 40ah lithium ion battery pack by using a 96V 28ah lead acid battery bank.

    The charging current required is 80 amps; a charge rate of 2C.

    I couldn't find any projects similar to this one on the internet which make me think if this is even possible.

    For now, I would like to get some ideas on how to draw 80 amps of current from the battery bank. The charging algorithm, BMS, and etc will come later. What kind of circuit/concept can be applied to this project?

    Any kind of help is very much appreciated. Thanks in advance!
     
  2. ronv

    AAC Fanatic!

    Nov 12, 2008
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    Use a buck converter.
     
  3. hadigan

    Thread Starter New Member

    Nov 8, 2011
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    This might be a stupid question, but how to design a buck converter that can withdraw 80 amps from the battery bank?
     
  4. MrChips

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    Oct 2, 2009
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  5. hadigan

    Thread Starter New Member

    Nov 8, 2011
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    Mr Chips, thanks for the response.

    Which part in the website are you referring to?

    If it is the charging current limit, the lithium ion battery that I'm using claims to have a maximum charge rate of 3C. Also, it won't be charged up until 100%, but only to 80% similar to the electric vehicle level 3 fast charging system.
     
  6. ronv

    AAC Fanatic!

    Nov 12, 2008
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    Here is a chip that could be used, but the design is not simple.

    You are aware you will only get one full charge from the lead acid batteries?

    Tell us more about the application. Maybe there is another way.

    You should think about the whole picture because the charge control may be a part of the buck converter. ie current limit, maximum voltage etc.
     
  7. hadigan

    Thread Starter New Member

    Nov 8, 2011
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    The application is to fast charge a light electric vehicle without using power from the grid.

    Yup, I'm aware of the charging limitation. What chip are you referring to, I couldn't see anything there.
     
  8. ronv

    AAC Fanatic!

    Nov 12, 2008
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