Internal resistance of a battery

Discussion in 'General Electronics Chat' started by Jas9, Sep 30, 2010.

  1. Jas9

    Thread Starter Member

    Sep 30, 2010
    Hello everybody,
    i want to know that did anyone on this forum developed a electrical circuit which calculates the internal resistance of a battery(car) depending upon the frequency of a alternator i.e if you have frequency as a input
    Basically what i think is using electrochemical impedance spectroscopy it can be achieved but i am bit confused with it so is there anyone who did this before???
    your help is always appreciated
  2. Nik

    Well-Known Member

    May 20, 2006
    IIRC, you can do it with a variable load and a DVM. V = i*(r + R1), solve for r...
  3. someonesdad

    Senior Member

    Jul 7, 2009
    Nik, I don't think that's what the OP is asking. I think he wants to measure the internal resistance as a function of a charging frequency. Jas9, I've come across a few web pages that indicate that this type of research has probably been done. Your best bet is to go to a library and do some looking around in the research literature.
  4. timrobbins

    Senior Member

    Aug 29, 2009
    Yes, there has been quite a bit of R&D into measuring the impedance of a battery at a range of frequencies, and using that information to assess and trend battery parameter changes of service life. Many papers at INTELEC conferences over the decades.

    Ciao, Tim
  5. Jas9

    Thread Starter Member

    Sep 30, 2010
    thanks everybody i will see to it