1. Ryza321's Avatar
    Hi guys, I usually lost about 3% overnight with 4G and power saving mode. But tonight a strange thing happened. For the first time, I got a huge battery drain. I leave the phone at 01:30 am with 25% and this morning I found it turned off. I think that is impossible to lose 25% over 7 hours, what could be happened? I would like to know if the fact that the battery has reached 0% and the phone shutted down can damage the battery.
    I am a little bit worried since I read a lot about the fact that the battery never should reach 0% and the phone doesn't have to shutdown.
    05-12-2016 03:39 AM
  2. ratsttam's Avatar
    My understanding is that the 0% isn't necessarily a true measurement. The phone will shut down on it's own before the battery really reaches 0% life. Usually the only way to reach true dead, is to leave the battery sit connected for a very long time in a depleted state. Understand this to be more than a couple weeks. I've had phones sit in a drawer for a couple years after I upgrade them, and find that the battery will still hold a charge when I go to play with them, or test something out.

    As far as losing 25% in 7hrs, it's quite possible, especially if there was an application in the background being super chatty with the network, or even creating a wake-lock (preventing the processor from sleeping).

    If this happens frequently, clearing the cache, or more invasive, a factory reset, should fix it. If it still happens after a factory reset, the battery may be faulty and needs replaced. The S7 is new enough that it should certainly be under warranty still.
    Ryza321 likes this.
    05-12-2016 04:04 AM
  3. Ryza321's Avatar
    Thank you for the explanation. Like i said this was the first time that the battery had a huge drain, but i didn't have any particular "battery-drainer" app on background. Something happend last night, but the important thing is that the battery is good. Usually i reach 4/5% before charging it, not less.
    05-12-2016 04:10 AM
  4. drinkoldcoke's Avatar
    My understanding is that the 0% isn't necessarily a true measurement. The phone will shut down on it's own before the battery really reaches 0% life. Usually the only way to reach true dead, is to leave the battery sit connected for a very long time in a depleted state. Understand this to be more than a couple weeks. I've had phones sit in a drawer for a couple years after I upgrade them, and find that the battery will still hold a charge when I go to play with them, or test something out.

    As far as losing 25% in 7hrs, it's quite possible, especially if there was an application in the background being super chatty with the network, or even creating a wake-lock (preventing the processor from sleeping).

    If this happens frequently, clearing the cache, or more invasive, a factory reset, should fix it. If it still happens after a factory reset, the battery may be faulty and needs replaced. The S7 is new enough that it should certainly be under warranty still.
    That is true, the device shuts down before the voltage of the Lithium Polymer battery drops too low because drawing current at too low of a voltage is what damages them. Really zero percent battery on your phone isn't zero and may be something like 5 percent really. It's whatever the manufacturer designs for the device and is independent of the battery. Some newer batteries are coming with built in chips to handle these sorts of things too as well as prevent over charging. I don't know if this stuff has made it to phones yet but it's showing up in hobby type lithium batteries for drones.
    Ryza321 likes this.
    05-12-2016 05:53 AM
  5. Ryza321's Avatar
    So, i have nothing to worry about if i understand it right
    05-12-2016 06:21 AM
  6. drinkoldcoke's Avatar
    So, i have nothing to worry about if i understand it right
    That is what I am saying.
    Ryza321 likes this.
    05-12-2016 06:30 AM
  7. Rukbat's Avatar
    0% once? You've probably lost 2 minutes of total battery life, so don't worry about it.

    Constantly discharging the battery below 40%? You'll need a new battery in 6 months.
    05-12-2016 04:04 PM
  8. Ryza321's Avatar
    0% once? You've probably lost 2 minutes of total battery life, so don't worry about it.

    Constantly discharging the battery below 40%? You'll need a new battery in 6 months.
    I always discharge my battery to 4/5% and until now I never had any problems with my phones.
    05-12-2016 04:56 PM
  9. ratsttam's Avatar
    And... you likely won't...

    Here is an article from a reputable company, about how the batteries work. It's the best way to describe it... This information is NOT specific to Apple products, but is rather "branded", but generic, information about Lithium batteries.

    Batteries - Why Lithium-ion? - Apple

    Charge your Apple lithium-ion battery whenever you want. There’s no need to let it discharge 100% before recharging. Apple lithium-ion batteries work in charge cycles. You complete one charge cycle when you’ve used (discharged) an amount that equals 100% of your battery’s capacity — but not necessarily all from one charge. For instance, you might use 75% of your battery’s capacity one day, then recharge it fully overnight. If you use 25% the next day, you will have discharged a total of 100%, and the two days will add up to one charge cycle. It could take several days to complete a cycle. The capacity of any type of battery will diminish after a certain amount of recharging. With lithium-ion batteries, the capacity diminishes slightly with each complete charge cycle. Apple lithium-ion batteries are designed to hold at least 80% of their original capacity for a high number of charge cycles, which varies depending on the product.
    One can safely replace "Apple" with any other manufacturer, and the data will be accurate.
    05-12-2016 10:00 PM
  10. Rukbat's Avatar
    I always discharge my battery to 4/5% and until now I never had any problems with my phones.
    4 to 5 percent? Lithium is NOT a deep-discharge technology. You may get away with it for a while, but my 11 year old V-551 battery, which still works fine, NEVER got that kind of treatment. (Neither did any of my lithium batteries, but that's the oldest one I still have.) If lithium could withstand constant deep discharge, manufacturers would knock tens of pounds off cars by using them (lithium is the lightest metal, lead is one of the heaviest, so even just that little box under your hood kills your gas mileage).
    05-12-2016 10:58 PM
  11. Ryza321's Avatar
    And... you likely won't...

    Here is an article from a reputable company, about how the batteries work. It's the best way to describe it... This information is NOT specific to Apple products, but is rather "branded", but generic, information about Lithium batteries.

    Batteries - Why Lithium-ion? - Apple



    One can safely replace "Apple" with any other manufacturer, and the data will be accurate.
    4 to 5 percent? Lithium is NOT a deep-discharge technology. You may get away with it for a while, but my 11 year old V-551 battery, which still works fine, NEVER got that kind of treatment. (Neither did any of my lithium batteries, but that's the oldest one I still have.) If lithium could withstand constant deep discharge, manufacturers would knock tens of pounds off cars by using them (lithium is the lightest metal, lead is one of the heaviest, so even just that little box under your hood kills your gas mileage).
    I don't want to speak about thing which i don't know, but you can understand that it's not normal charge the phone when it reach 40%. In a normal day of use, the people doesn't think to charge the phone when it's at 40%. But i'm curious, if 4/5% is not good, what is the minimum percentage of battery before the phone has to be charged?
    05-13-2016 03:18 AM
  12. drinkoldcoke's Avatar
    4 to 5 percent? Lithium is NOT a deep-discharge technology. You may get away with it for a while, but my 11 year old V-551 battery, which still works fine, NEVER got that kind of treatment. (Neither did any of my lithium batteries, but that's the oldest one I still have.) If lithium could withstand constant deep discharge, manufacturers would knock tens of pounds off cars by using them (lithium is the lightest metal, lead is one of the heaviest, so even just that little box under your hood kills your gas mileage).
    You can keep it charged all the time too and they'll still go bad. There is so much more to it, and Lithium batteries are not the same as lithium Ion, or lithium polymer. They all tolerate charge/discharge cycles differently.
    06-04-2016 12:31 PM
  13. chanchan05's Avatar
    0% once? You've probably lost 2 minutes of total battery life, so don't worry about it.

    Constantly discharging the battery below 40%? You'll need a new battery in 6 months.
    Not true. My mom drains her battery usually to 15% before charging. Her phone batteries usually hold up more than two years before needing replacement. Her S3 had it's first battery change since being bought 3 years ago just last month.
    06-04-2016 10:18 PM
  14. chanchan05's Avatar
    I don't want to speak about thing which i don't know, but you can understand that it's not normal charge the phone when it reach 40%. In a normal day of use, the people doesn't think to charge the phone when it's at 40%. But i'm curious, if 4/5% is not good, what is the minimum percentage of battery before the phone has to be charged?
    I'll copy my post from another thread:

    I normally charge at 30-40%. Due to my line of work, I need the phone always available, so I charge it whenever I am able and carry around a power bank.

    However on Li ion technology, you actually want to keep it topped up as often as possible to reduce usage of charge cycles. The phone has a limited number of charge cycles, after which capacity deteriorates. Usually this is at 500-600 cycles (1 cycle is discharge from 100 to 0, then charge 0 to 100). This is good for about 18mos if you fully discharge and charge your phone once a day. The closer you are to zero, the closer you are to this number.

    However, not fully discharging the phone has benefits of increasing the number of charge cycles. Cycling at 50% (never letting it go below 50%) gives you 1500 cycles. At 75% you get 2500 cycles. So basically, you could turn your 3600 battery good for 18mos before start of capacity deterioration to a 1800mah battery good for 54mos.

    Your choice becomes to make the most of the battery's capacity and drain it as low as you can before charging, or try to prolong it's lifespan. Personally, I just try to charge at 40% when I can, but don't mind when I reach 10% every now and then if I couldn't help it.


    http://batteryuniversity.com/learn/a...ased_batteries
    Also note that charge cycles aren't fixed. They have exponential deterioration. You'd normally think that if 100-0 is 500, then 100-50 is 1000 cycles, but it's not, and cycling at 50% gives you 1500 cycles.
    06-04-2016 10:20 PM

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