1. Android D's Avatar
    You guys ever wondered when your phone charges to a 100%, and you immediately unplug it knowing it's fully charged, and the battery suddenly drops to like 97% or 99%.

    The only way I found around this is to keep it plugged in for an additional 30 minuted after it's "fully charged" to make sure when I unplug it is 100%!! This is super annoying !!

    And how long does it take for your phone to drop from 100% to 99% when you are USING IT?? I know if it's on standby, it takes longer, but I mean when ur actual screen is ON!
    02-16-2015 09:42 PM
  2. hamsterwheel's Avatar
    It doesn't take long for mine action, but that's because I unplug it every morning and then check all my messages, and other things so it's bound to drop..
    02-16-2015 09:46 PM
  3. Android D's Avatar
    It doesn't take long for mine action, but that's because I unplug it every morning and then check all my messages, and other things so it's bound to drop..
    So I am guessing you leave it to charge overnight?
    02-16-2015 10:22 PM
  4. hamsterwheel's Avatar
    So I am guessing you leave it to charge overnight?
    Yes I do. Always have with all my phones. Never had any problems
    02-16-2015 10:31 PM
  5. Android D's Avatar
    Yes I do. Always have with all my phones. Never had any problems
    oh ok so yeah when u unplug it it doesn't drop right back to 99% or something lower like mine does sometimes...it's only when u use it drops down, which is expected!
    02-16-2015 10:32 PM
  6. Bosbouer's Avatar
    Using the same method as hamsterwheel BUT not using the phone immediately off charger, I find it drops to 99% after about 90 minutes. I check and answer emails still on the charger. Then unplug and do nothing further on the phone until about 07:30 SAST.

    I did note the same tendency as you did after unplugging at as close to reaching 100%...it does drop quicker than in the morning cycle.

    Does it bother me? Nope not at all.
    02-16-2015 10:57 PM
  7. Rukbat's Avatar
    The phone doesn't measure the state of charge of the battery (that can only be done chemically, and by destroying the battery), it measures the terminal voltage of the battery under a bit of load (whatever the phone is drawing). With the charger connected, the voltage on a battery at about 95% is the same as the voltage on a battery with 100% charge and no charger connected, so the phone "guesses" when the battery is fully charged. Since the charge stops when the battery is actually fully charged, there's no harm in leaving it on the charger for an extra hour or 5 (as long as the battery stays cool).

    Discharging is the same guessing game - this is the voltage, so what's the state of charge? That would depend on the load, which varies constantly. I've sometimes maintained "100% charge" with the screen on for 10 minutes, sometimes it's down to 99% after 5 minutes - both with an overnight (so really 100%) charge.

    I'm not OCD, so as long as the batteries (I always have 2 for any phone - if I can't get to an outlet or car to charge, and the battery in the phone drops to 40%, I swap batteries) last longer than I want the phone to, I'm happy. (The original batteries in my 10 year old V551 "spare" phone still give me full usage from a charge, and the phone is useful only as a phone or an emergency 640X480 camera - it paid its dues long ago.) If I'm still using my Note 3 in 9 years, with the same batteries, I won't complain. Even if the batteries drop from 100% to 99% as I pull the charger plug out.
    Almeuit likes this.
    02-16-2015 11:34 PM
  8. Almeuit's Avatar
    ^^^^ What the two posts above me said .
    02-17-2015 09:59 AM
  9. worwig's Avatar
    What Rukbat said. The phone software is actually doing a pretty good job at guessing the state of charge based on the battery voltage, and the load. The best thing to do is to leave it on charge a little longer to let the software and hardware 'sync up' at closer to a true 100%.
    My devices always get a full overnight charge. In the morning they hold 100% for a fair amount of time. I just checked and my N4 is still at 99%.
    Long ago the manufacturers would only report battery level in 10% steps, even though internally they had 1% (or better) data. They know that a lot of people would panic if they saw sudden 2 or 3% changes. So they totally hid that info.
    02-17-2015 10:00 AM
  10. Android D's Avatar
    WOW!!

    pheww...never knew it was so complicated.

    I just wanted it to be like other phones that is when it's charged to 100%, it stays at 100% immediately after and not drop suddenly to like 99% or 98% after unplugged..oh well have to deal with it!
    02-17-2015 10:25 AM
  11. sparker04's Avatar
    WOW!!

    pheww...never knew it was so complicated.

    I just wanted it to be like other phones that is when it's charged to 100%, it stays at 100% immediately after and not drop suddenly to like 99% or 98% after unplugged..oh well have to deal with it!
    I'm in the same boat as you, I had no idea it was so complicated. Thanks everyone for the info!
    02-17-2015 12:49 PM

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