01-04-12 11:35 AM
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  1. esoRdeR's Avatar
    Hello!

    I had gotten the 16GB PlayBook for Christmas and I noticed something when I charged it the other night. I'm not sure if it's normal or not.

    After it was finished charging, I unplugged it, shut it down and went to bed. It was close to 11pm. When I turned it on today(around 2:30pm), the battery was at 97%. I had all apps closed so nothing was running in the background and both the wifi and bluetooth were off.

    Is a 3% drop during that time frame normal considering the PlayBook was shut down and not on standby?
    01-01-12 06:47 PM
  2. mczack's Avatar
    its normal mine once did around 7 percent over night and i turned it off as soon as it was fully charged now i charge mine overnight
    01-01-12 07:02 PM
  3. jafobabe's Avatar
    If you have ever seen the FedEx guy tossing the PC monitor on YouTube, you never know how your PB was treated in getting to you, or to where the PB was purchased.

    Give the battery a few cycles of charging and it probably restore it's self to a more normal battery useage.

    Click on the link below my signature, for tons of Tips and Tricks for the Playbook.... this is a work in progress by all the knowledgeable posters from this forum.

    Hope this helps!

    And Welcome to the forums!!
    KermEd likes this.
    01-01-12 07:07 PM
  4. donahugh's Avatar
    Rechargeables do diminish when not in use but very slowly.
    01-01-12 07:08 PM
  5. TheScionicMan's Avatar
    There are some minor processes that run even when the PB is shut off. The clock is one example. It also takes a little bit of power to boot up the device, so I would say it is not abnormal.
    01-01-12 07:18 PM
  6. esoRdeR's Avatar
    Thanks.

    I was browsing around that thread in your signature, jafobabe and someone said that leaving it on standby instead of shutting it down will save the battery life. Is this true? I thought that would drain it more.

    donahugh, I know they diminish while in standby but also when it's shut down?

    Sorry for all of the questions everyone. I'm obviously very new to the PB.
    01-01-12 07:19 PM
  7. jafobabe's Avatar
    Thanks.

    I was browsing around that thread in your signature, jafobabe and someone said that leaving it on standby instead of shutting it down will save the battery life. Is this true? I thought that would drain it more.

    donahugh, I know they diminish while in standby but also when it's shut down?

    Sorry for all of the questions everyone. I'm obviously very new to the PB.
    Standby will reduce the battery usage somewhat, and when you power up it will take alittle more battery usage to get it totally on.
    I leave mine in standby most of the time and use the 'airplane' mode to shut off the bluetooth and wifi.. then I wake it up by doing a top to bottom swipe, tap the airplane and then off... wait a couple of seconds and it will re-establish the BT and Wifi.
    Last edited by jafobabe; 01-01-12 at 08:37 PM.
    esoRdeR likes this.
    01-01-12 07:54 PM
  8. KermEd's Avatar
    Thanks.

    I was browsing around that thread in your signature, jafobabe and someone said that leaving it on standby instead of shutting it down will save the battery life. Is this true? I thought that would drain it more.

    donahugh, I know they diminish while in standby but also when it's shut down?

    Sorry for all of the questions everyone. I'm obviously very new to the PB.
    I wouldnt be surprised if this was in a large part because your device is new. You will have some fluxuations for the first few weeks of use. Its because the value you see is a percentage, it doesnt really represent the battery charge accurately.

    For example, lets say (dont take literally here) your battery holds from 46,000 - 974,000 electrons day one. Once the battery has been used all day, it would have changed. Day two it might expand its range a bit or contract it. So it might find a bandwidth of 45,869 - 997,340. Because you were sitting at about 974k your charge is now only at 97 percent. But really your charge hasnt changed.

    Youll see a bit of fluctuation for the first while. It is also not uncommon to see the batter increase 3-5 percent the next day too. Remember the percentage is really a best-guess too and can be i fluenced by things.

    If you loose 10 plus id be more concerned. Maybe check it for the next week and make sure it levels off. 1-2 per poweroff/poweron is normal. The bootup would use 1 percent and 1 percent is the poweroff+tolerance+internal clock. And id say give or take 1 percent too. So 3 seems normal.

    Illbet if you powered off for a week once levelled, a 3-4 charge loss would be expected. A one day power off a 2-3 charge loss would be normal.


    Just imo

    Ed
    jafobabe and esoRdeR like this.
    01-01-12 07:55 PM
  9. peter9477's Avatar
    The % level is merely an estimate, a calculated value that doesn't represent something physical. There's no "percent full" for batteries: there's only the voltage. Anything else is an attempt to translate a non-linear, complex reality into a simplistic linear value that humans can deal with, like a percent.

    What it means in this case, among other things, is that if it says 100% the instant you take it off the charger, and it shows 97% a minute later (or the morning after), all that's happened is that some software isn't doing this translation quite as flawlessly as we'd like it to, and you're seeing the side effects. It means nothing with respect to how much charge your battery is actually storing, and it does NOT mean that you really lost three percent of the charge in the battery overnight, with the tablet off.

    Heck, I've sat here watching mine as it jumped from a reading of about 42% to a reading of 47%, instantly, untouched, and with no apparent reason for that. It's software attempting to deal with very tricky real-world physical values, and this is the best we can get.
    esoRdeR, glassofpinot and KermEd like this.
    01-01-12 08:04 PM
  10. peter9477's Avatar
    By the way, just a quick point on the "does standby save battery" issue.

    No, it doesn't... standby uses 50mW (0.050W) or so on a continuous basis.. that means it's consuming battery power, so it can hardly save battery.

    On the other hand, it takes a while to boot up... I forget exactly, but let's assume it's two full minutes. It has the screen on for much of that, and uses close to 4W during that period. 4W for 2 minutes is 0.13Wh, which is about 0.7% of a typical 90%-health battery. So shutting it down and turning it back on doesn't exactly use no battery either.

    Obviously, however, if you leave it off for long enough, you'll save battery versus having it in standby for the same period. The break-even appears to be around 2.7h. Technically, therefore, leaving it in standby for more than (say) 3h means you're actually losing power (a tiny bit) relative to having it off for the same period, then "wasting" some power turning it on.

    In any case, correctly operating PlayBooks should use only a few percent overnight on standby, so if the convenience factor of being able to swipe it on instantly any time you want it is enough to outweigh the disadvantage of losing those few percent, then clearly you should just leave it in standby.

    I'd only turn mine off if I were planning to leave it untouched for about 3 days or more, which is an eventuality I find it hard to imagine right now! :-)
    jafobabe, esoRdeR and KermEd like this.
    01-01-12 08:10 PM
  11. esoRdeR's Avatar
    This is great info! I tend to use my PB everyday so leaving it on standby makes more sense. I did notice the fluctuation that peter9477 mentioned the other day. The percentage went up around 5% while I was listening to music. I've seen this before with my iPod Touch.

    I'm going to put my PB in Airplane mode and then standby tonight like jafobabe suggested.

    Here's a stupid question. Should I let the battery drop to a certain percentage before charging it?

    Thanks again!
    01-01-12 08:28 PM
  12. peter9477's Avatar
    With Lithium-Ion batteries (as the PlayBook has) there's really not any need to let it drop to a certain point before charging. There's no real "memory" as with older technologies, or such issues.

    The only reason to consider not recharging it too often, always at high levels, is to help out that calibration routine in the software, which ultimately is responsible for the % level estimate that we all rely on. If you periodically do a fairly full drain, then a fairly full recharge, you're probably (and apparently, according to RIM) helping it update the measurements so it will be reasonably accurate.

    I tend to deliberately do a complete drain to 0% (actually till it shuts itself off) once every month or so, partly because I like generating interesting data for Battery Guru ;-) and partly to make sure my "health" reading is updated and as accurate as it can be. (The % level is derived mostly from that health value, so it's the key.)
    01-01-12 08:41 PM
  13. esoRdeR's Avatar
    With Lithium-Ion batteries (as the PlayBook has) there's really not any need to let it drop to a certain point before charging. There's no real "memory" as with older technologies, or such issues.

    The only reason to consider not recharging it too often, always at high levels, is to help out that calibration routine in the software, which ultimately is responsible for the % level estimate that we all rely on. If you periodically do a fairly full drain, then a fairly full recharge, you're probably (and apparently, according to RIM) helping it update the measurements so it will be reasonably accurate.

    I tend to deliberately do a complete drain to 0% (actually till it shuts itself off) once every month or so, partly because I like generating interesting data for Battery Guru ;-) and partly to make sure my "health" reading is updated and as accurate as it can be. (The % level is derived mostly from that health value, so it's the key.)
    I completely drain my Touch once a month so I'll do the same with my PB.

    So by high levels, do you mean charging it when the battery is at 80 or 90%? I normally wait until the battery is down at least 50% before charging it.
    01-01-12 08:54 PM
  14. herculesinwyoming's Avatar
    my playbook has been on 36 hours with some light use and its about time to charge it.
    crazy but true
    01-01-12 09:06 PM
  15. peter9477's Avatar
    I completely drain my Touch once a month so I'll do the same with my PB.

    So by high levels, do you mean charging it when the battery is at 80 or 90%? I normally wait until the battery is down at least 50% before charging it.
    Yes, that's what I mean. It could well help the calibration to ensure you discharge well below 50% some times, since the curves are non-linear, but I have no data on which to base a conclusion like that yet.
    TimmyTRocks likes this.
    01-02-12 12:56 AM
  16. patrialist2000's Avatar
    Mine has a very good battery life
    01-02-12 02:49 AM
  17. esoRdeR's Avatar
    Good morning everyone.

    Well I left my PB on standby last night. The bluetooth is never on and I forgot to switch it to Airplane mode(I did turn off the wifi though). The battery went from 29% to 24% and when I turned the wifi on and signed in here, it went up to 25%.

    So is a 4%-5% drop normal for being on standby for about 10.5 hours? I expected the battery to be lower then that so I think it's pretty good.
    01-02-12 09:40 AM
  18. peter9477's Avatar
    Anyone can easily do their own math on this.

    The battery has a nominal 19.98Wh (watt hour) capacity.

    Take your battery health (reported by Battery Guru). I'll assume 90% here.

    Multiply the two to get your current max. capacity (which will slowly decrease over the life of your device). 19.98 * 0.9 is 17.982Wh.

    Multiply by the percentage drop, e.g. 5%: 17.982 * 0.05 = 0.8991Wh

    Divide by the duration in hours to get average watts, e.g. 10.5: 0.8991Wh / 10.5h = 0.087W or 87mW. If we assume 4% it was only 69mW.

    So your device was consuming 69-87mW all night, on average, which is in the ballpark. I generally get 50-60mW for my 1.0.8 device, and more like 80mW for the 2.0. Some of the PlayBooks I've tried are closer to 100mW, suggesting variation of almost +100% based on hardware differences. I'd consider anything above that suspicious and a possible sign of trouble.
    01-03-12 10:53 AM
  19. Chaddface's Avatar
    I completely drain my Touch once a month so I'll do the same with my PB.
    I have done the same a few times with no ill effects. I just wanted to mention that you should probably let it charge for at least an hour or so before booting. You will see a greenish flashing light indicating charging and a solid when it's done.
    I have seen a few posts with issues after trying to boot a PB with a dead battery. There may be no issue at all but I would err on the side of caution.

    Peter,
    Have you ever tried to boot up right after plugging in a drained PB?
    esoRdeR likes this.
    01-03-12 11:10 AM
  20. zorecati's Avatar
    Fully discharging a lithium ion battery is a bad idea.

    How to Prolong Lithium-based Batteries - Battery University

    "Similar to a mechanical device that wears out faster with heavy use, so also does the depth of discharge (DoD) determine the cycle count. The smaller the depth of discharge, the longer the battery will last. If at all possible, avoid frequent full discharges and charge more often between uses. If full discharges cannot be avoided, try utilizing a larger battery. Partial discharge on Li-ion is fine; there is no memory and the battery does not need periodic full discharge cycles other than to calibrate the fuel gauge on a smart battery."

    Another link...

    The care and feeding of Li-Ion batteries | TechRepublic
    Last edited by zorecati; 01-03-12 at 11:58 AM.
    01-03-12 11:50 AM
  21. peter9477's Avatar
    I encourage anyone with an interest in batteries and the technical aptitude to process all the info to read that site thoroughly, as it has a great deal of good information, when taken as a whole. (I've read most of those pages a half dozen times now, and still don't feel like I've got a complete handle on it all.)

    Most people are not in a position to judge the meaning of small snippets of information such as this, and phrases such as "fully discharging a lithium ion battery is a bad idea" are, I believe, dangerous to make as unqualified statements. It's called spreading FUD (Fear, Uncertainty, and Doubt).

    Among other things to consider: "fully discharging"... what's "full"? You'll note in the referenced page that they consider "100%" discharge to be 3.0V, which is well below the 3.4V minimum that the PlayBook allows (the point at which it shuts itself off). From one point of view then, it's impossible to "fully discharge" your PlayBook, since it shuts itself off well before it reaches "100%" discharge, per the terms used on that page.

    Also, note the other statements there which hint at how keeping the voltage high (which they consider "above 4.1V") is also "bad". "Exposing the battery to high temperature and being at full state-of-charge for an extended time can be more damaging than cycling." Taking information and quoting this stuff out of context is careless, in my opinion. Note that the PlayBook allows the voltage to reach 4.2V before it stops charging.

    Everyone should trust that RIM's engineers have, in conjunction with the battery manufacturer's own technical experts, come up with a system which provides an excellent balance between long battery life, safety, capacity under typical charging scenarios, and ease of use.

    Attempting to improve on that based on out-of-context "scary" quotes would be foolhardy, and normal users should simply watch for unusual readings and conditions (e.g. those who've identified higher-than-normal standby power consumption), and avoid extremes if possible.

    I don't think I'd recommend either discharging-until-power-off every time you use the device, or keeping it on the charger literally all the time: I expect either extreme is somewhat worse than anything in between, where you use the product off the charger, until any battery level, and then recharge it partially or fully, and do it again.
    Chaddface and esoRdeR like this.
    01-03-12 12:10 PM
  22. zorecati's Avatar
    My links were geared more twords those who state they fully discharge their battery once a month. I simply stated it was a bad idea, but most need to read the why from a source other than some dude named zorecati on a forum. I know I wouldn't
    01-03-12 12:19 PM
  23. TheScionicMan's Avatar
    Anyone can easily do their own math on this.
    Now that is funny. I can barely follow you doing it...
    Chaddface likes this.
    01-03-12 12:33 PM
  24. doxa sub750T's Avatar
    After a week or so, I found I lost about 2% when shut it off fully after a full charge overnight. On the other hand, I lost about 3% when leaving it on Standby mode with WiFi on only, no BB Bridge, BT, etc.

    I don't see a real need to power this baby down unless I need to put her away for week.
    01-03-12 12:53 PM
  25. esoRdeR's Avatar
    My links were geared more twords those who state they fully discharge their battery once a month. I simply stated it was a bad idea, but most need to read the why from a source other than some dude named zorecati on a forum. I know I wouldn't
    If you look through this thread you will see that I am not the only one who does this. Not only that but I also don't hold myself to discharging it once a month and never have I done this more then once a month. More times than not, I do this once every few months and many times it's not intentional. If I'm gathering information on a topic of interest or playing a game, it's easy to lose track of the battery life.

    peter9477 has already gave me very valuable advice on this so I'll just stick with what he had posted.

    I have done the same a few times with no ill effects. I just wanted to mention that you should probably let it charge for at least an hour or so before booting. You will see a greenish flashing light indicating charging and a solid when it's done.
    I have seen a few posts with issues after trying to boot a PB with a dead battery. There may be no issue at all but I would err on the side of caution.
    Thanks for the heads up on that. I'd probably just leave it be until it's fully charged.
    01-04-12 11:02 AM
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