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Measuring 2 Volt Cells in Parallel

Discussion in 'Renewable Energy' started by bryan1, Aug 4, 2012.

  1. bryan1

    bryan1 Well-Known Member

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    G'Day Guy's,

    The main problem with measuring 2 volt cells with a common ground is each cell will rise 2 volts on average so that causes a major problem using ADC on a pic. I have been talking with a mate over this issue and we came up will a possible solution that uses a RFpic say a RF12f675. Now by doing it this way each pic can measure 2 cells and have a IR sensor to be signalled when a packet needs to be sent. Each pic can be powered by 2 cells so power won't be a problem.

    This is one complicated idea but if any guy's have any easier way chime in as this is one project I want to do.

    Cheers Bryan
     
  2. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    I'm a bit confused about exactly what you're trying to do?.

    Do you mean you've got a number of lead/acid (2V) cells in series, and you want to individually measure the voltage of each cell?.

    Simply use a DPDT relay for each cell, and switch both ends of the individual battery you're testing to the PIC monitoring circuit.
     
  3. nickelflippr

    nickelflippr Member

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    Any modern PIC of say 18 pins is going to have 12 adc (e.g. 16f1827) and up from there to 30 channels on a 40 pin device (e.g. 18f46k22). Hook them up, and just subtract the previous reading from the next one up the ladder of 2V battery cells.

    EDIT: Of course you would have to use a voltage divider to cover the range of the overall battery pack :)
     
    Last edited: Aug 5, 2012
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  4. dave

    Dave New Member

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  5. alec_t

    alec_t Well-Known Member Most Helpful Member

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    If the 2V cells are in parallel, as the post title states, then they will all have the same terminal voltage; so a single-channel ADC will suffice.
     

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