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Measuring SoC/life on Li-ion battery - help please

  1. Jul 24, 2012 #1
    Hi all,

    I've been trying to find some sort of multimeter/voltmeter/etc that will allow me to get an accurate (and independent of the handset) read on state of charge, or remaining life, on a standard cell phone li-ion battery.

    I've found a few voltmeters and the like, but my understanding is that it's not as simple as that...?

    I'd be very grateful if anybody know of such a device or can give me any information.

    Many thanks,
  2. jcsd
  3. Jul 24, 2012 #2


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    Gold Member

    rthomas_uk, Welcome to Physics Forums!

    Knowing the State-of-Charge (SOC) of a lithium-ion battery is not so straightforward. Yes, a quality voltmeter is necessary, but some calculations are needed also. See:


    "If a Li-ion battery is used in applications where knowing the SOC is crucial (such as Electric Vehicles), there is a need to measure its actual capacity. The battery capacity is measured by integrating its current from completely full to completely empty (or vice-versa)."
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