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  1. #1
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    Battery meter is whack?

    (I saw a lot of threads on battery but not one focused around this issue so...)

    I'm using standard WM6/MITS software that came w/ phone, and extended battery.

    My battery meter does not seem to reflect reality. I don't know if that's a function of WM6's battery meter being poor, or that Li-Ion batteries not reporting their levels accurately.

    Example: Yesterday, unplugged my phone at 8am. Took it to work for 9 hrs (3-4 hours were in basement or in bad/no coverage areas). Used it moderately (2-3 brief calls, 6 emails sent, 25 rec'd). After 10 hrs I got low-battery warning and meter showed 20% (as does #4357*). It's been stuck on 20% ever since! (I did NOT charge it last night) That's 17+ hrs stuck at 20%! And 27+ hrs since last charged.

    Obviously it's nice to know it can go more than 24 hrs, but what good is a battery meter if it warns you to conserve your battery and then goes on to last for almost 24 hrs after that?!

    Is this just what we have to live with or is there anything that can be done to improve this... have the battery meter reflect reality better?

  2. #2
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    LiIon batteries don't have the same charge and drain behavior as has been typical with past battery types like NiCad and NiMH. The batteries tend to "bulk up" in a given block based on how they are charged on a regular basis. Since most people don't let their phones run doen, they usually present themselves are "top heavy"; they usually report a full or nearly full charge for half or more of their discharge cycle. However, depending on your charging habits, the "plateau" can be in a different place. For example, if you always have let your phone go totally empty between charges it might drop down to a low number quickly and plateau there instead of doing it at the 80-90% level like most people see.

    With mine, there are two "plateaus"; one is at 90% - it will stay there for the first 12 or so hours of standby, then drop to the second one at 65% for another 12 or so, then drop quickly to "low battery" status. My old Motorola phone would sit at full bars until about two hours before it would go empty as well.

    There's not really anything to be done, because the way the technology behind the batteries themselves drains is not strictly linear, and hence it's not really practical to measure it in a linear fashion like we try to do.

  3. #3
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    Interesting. So you're saying that there's nothing wrong w/ WM6's Battery Meter... it's just showing what the Li-Ion's true status is?

    The problem is inherent to Li-Ion technology? So all devices which use Li-Ion's should show similar non-linear, non-steady charge %'s?

    Wow, that pretty much sucks.

    When your device warns you it has 20% left after 10 hrs but then goes on to work for another 17 hrs after that, it means that the gauge is pretty useless. (What if automobile gas gauges were this bad?!)

    As a result I guess one natural reaction then is to ignore low-battery warnings and basically say "sorry I don't believe it... I know better than you do... I bet there's more life left".

    But it could get even worse if it was the other way around. It would say you have 20% left but then only work for a matter of minutes. I sure hope Li-Ion's always tend to report low-battery too early, rather than too late.

  4. #4
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    I'd say "basically true".

    Sony was (and is) a pioneer of battery status. They have run some form of "processor" in many of their laptop batteries that gather the data about how the battery acts and report a more accurate picture of time and percent remaining. TI (now Acer) had some of that stuff in their batteries, too.

    There are also software programs (for laptops, anyway... dunno about PPCs) that do similar stuff with software by watching the history of the performance of the battery (as long as it's the SAME battery - they are all a little different) and report it as more linearly accurate.

  5. #5
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    Related but slightly OT...

    Is it a bad thing w/ Li-Ion to let them run down to near/zero?

    I know with NiCad's because of memory-defect issue, it was recommended to do that initially and sometimes later on I believe.

    But Li-Ion seems like a totally different animal. Do they like to be fully discharged or are things better if they're charged when around half full?

    I'm thinking both about getting maximum hours per each charge, and minimizing the battery getting worn out over the long-run.

    I'm also asking because the other day I decided to just run my extended battery until it was empty and see how many hours I got. Well after nearly 34 hrs and while the meter still said 5% I had to start recharging again.

    I hope I didn't make the battery any worse by letting it go down to 5%.

    p.s. Of those 34 hours, about 21 of them (62%) were while the battery meter showed 5%-20%. That seems to confirm what the others have said about Li-Ion's non-linear charge-remaining read-out.

  6. #6
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    From what I've read, lithium ion batteries don't mbar from the "memory" issues, but they do decline with every charge/ discharge cycle.

  7. #7
    Alchemist dfkimbro's Avatar
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    Check out the guidelines at the bottom of this page from BatteryUniversity.com for lithium ion usage, charging, and storage...How to prolong lithium-based batteries.

    They also talk about resetting the battery charge meter with a full discharge every 30 charges.
    -Duncan

    "If it can't be expressed in figures, it is not science, it is opinion" - R. Heinlein

  8. #8
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    Quote Originally Posted by dfkimbro View Post
    Check out the guidelines at the bottom of this page from BatteryUniversity.com for lithium ion usage, charging, and storage...How to prolong lithium-based batteries.

    They also talk about resetting the battery charge meter with a full discharge every 30 charges.
    Thanks for that Duncan. Very interesting!

    With all the history we have w/ NiCad's and their memory defect, it's hard to redo your battery thinking & habits.

    So I guess it was not bad for me to let my battery run for 34 hrs down to 5%. Perhaps this will help recalibrate it so that future meter %'s are more "normal".

  9. #9
    Alchemist dfkimbro's Avatar
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    You're welcome...although the guidelines are a bit unrealistic. I don't pop out every battery once I plug a device in, nor do I store my batteries in the fridge.
    -Duncan

    "If it can't be expressed in figures, it is not science, it is opinion" - R. Heinlein

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