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Measuring battery module internal resistance

Discussion in 'Gen 2 Prius Technical Discussion' started by xland, Jun 30, 2020.

  1. xland

    xland New Member

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    i read in other threads gen 2 about battery module internal resistance measurements

    what procedure and instrument are you folks using ?

    looking into a decent ESR meter
    need 4 decimal places for resolution and internal frequency of 1khz
    some have 4 wires for the probes

    can someone with experience confirm the minimum specs an ESR meter would require please ?

    regards
    Xland
     
    #1 xland, Jun 30, 2020
  2. ChapmanF

    ChapmanF Senior Member

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    An ESR meter would typically be for measuring the equivalent series resistance of a capacitor, hence the need for fancy AC waveforms.

    Internal resistance of a DC battery doesn't require nearly so much ceremony; it's the voltage change from open when you apply a known current, divided by that current.

    The Prius battery ECU computes it automatically for every pair of modules in the battery and can report the numbers to you over the diagnostic port. I suspect those are the numbers a lot of people are using.
     
    #2 ChapmanF, Jun 30, 2020
    SFO likes this.
  3. xland

    xland New Member

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    Understood sir,
    But I guess you would need a load of some sort to get some decent current
    Say an amp or 2 thru a load resistor ?
     
    #3 xland, Jul 1, 2020
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