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  1. Thread Author  Thread Author    #1  

    Default effects of constant on off charging?

    Are there any negative effects of charging multiple times throughout the day vs once every night? People are saying to plug it in when you can, car office, etc. There has to be some type of negative effect. Does a battery not have a maximum number of charging cycles? With my Gnex, when i did that throughout the day or noticed it was to low to finish doing something like complete a call or what have you, it would always get hot during charge and use. Just curious.
  2. #2  
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    Default Re: effects of constant on off charging?

    These days it no longer matters as the battery is no long independent from the OS, so you can charge and uncharged as much as your want!
  3. Thread Author  Thread Author    #3  

    Default Re: effects of constant on off charging?

    Quote Originally Posted by Sooks View Post
    battery is no long independent from the OS
    ?
  4. Thread Author  Thread Author    #4  

    Default Re: effects of constant on off charging?

    after some googling their is definitely a finite number of charging cycles a lithium ion polymer can go through. no ones site has divulged this number. one site (questionable) said 500. apple did not.
  5. #5  
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    Default Re: effects of constant on off charging?

    I have looked into this issue a lot because I became a bit obsessed with the effects of inductive charging on my Palm Pre Plus a couple years ago. A good place to start reading is Battery University. Believe it or not, the Apple website also has some good info, too. Though I have studied electrical engineering and physics extensively and done a lot of reading on the subject of batteries, I still don't feel like I have a 100% complete understanding of the best way to deal with battery charging, especially since the chemistry involved is always evolving. That said, I think there are five main enemies of the lifetime of current lithium ion battery technology:

    1. Heat: letting the battery heat up, and especially using the battery while it's hot is definitely detrimental to its longevity. My Pre Plus used to get fairly toasty while inductively charging sometimes, so it's something to watch when charging using that method. Playing a game or doing something else intensive while charging can also make the phone heat up.
    2. High voltage: yup, as far as I can tell, charging the battery fully is not in fact good for it. You obviously need to go for a full charge if you want to maximize battery life over a single discharge, but I think that doing so will lead to a more rapid degredation of the battery capacity over multiple charging cycles. I'm not sure if the battery manufacturers (or the makers of the charging circuit) take normal smartphone use into account when setting the charging parameters or not. Maybe they do something to compensate for the negative effects of prolonged high voltages.
    3. Deep discharge: using a lot of the battery's capacity is harmful to it. I don't know at what point in the discharge cycle it really starts to become a problem, but I just try to keep mine from going too low whenever possible.
    4. Usage of battery cycles: a Li-Ion battery is rated for a certain number of cycles before it loses a certain percentage of its capacity. This is a well known quantity, and you can look up graphs of capacity versus number of charge cycles for common batteries. A cycle is a full 100% discharge, but if you, say, use your battery repeatedly between 100%-95% (a hypothetical repetition of 5% capacity discharges with charging in between), you need 20 of those %5 usages to equal a full cycle. So in that sense it doesn't matter how often or how many times you charge.
    5. Time: Li-Ion batteries degrade over time, even if you don't use them, and that's just the way it is.


    So, as far as I can tell, an ideal usage scenario would be something fairly unrealistic like never discharging the battery below 60% and never charging it above 90% or something along those lines. I think the electric cars like the Tesla that use Li-Ion batteries actual have a charging/discharge cycle something like that to make the batteries last as long as possible, though those batteries are being used in a different way and are expected to last longer than those in smartphones. With my Galaxy Nexus I just charge it whenever possible, so it spends a lot of time in the high voltage state. I haven't worried about it because I know I could always pop in a new battery without breaking the bank. Now that I will be getting a DNA tomorrow, though, I'm thinking more about my charging strategy since the battery can't be replaced without some major surgery.

    I guess the important thing is to figure out which of the factors I listed above is the most detrimental and plan accordingly. As far as I cant tell, though, the general consensus seems to be that frequent charging is better than deep discharging, so I will probably keep trying to top off rather than letting the battery run down a lot.

    Edit: Here's the relevant summary straight from Battery University on how to prolong Li-Ion battery life:
    Keep cool, battery lasts longest when operating in mid state-of-charge of 2080%. Prevent ultra-fast charging and high loads.
    Of course this still leaves some question about the best way to treat the battery because we don't know exactly how the manufacturer of the device has chosen to report the percentages. If they are actually percentages of the full allowed voltage (either 3.6 or 3.7 V) then the 20-80% figure is accurate. However, if the percentages are scaled in some way then it won't be exactly right anymore. But the main point still stands: avoid 0% and 100% for best battery longevity. It would be nice if smartphones would come with the option to limit battery charging below 100% so that the phone can be left plugged in all night without harming the battery. Some laptops have that capability, as do some smartphones through custom kernels (Franco's kernel for the Galaxy Nexus has that option, I think).
    Last edited by gharkay; 11-28-2012 at 07:58 PM.
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    Default Re: effects of constant on off charging?

    Quote Originally Posted by gharkay View Post
    I have looked into this issue a lot because I became a bit obsessed with the effects of inductive charging on my Palm Pre Plus a couple years ago. A good place to start reading is Battery University. Believe it or not, the Apple website also has some good info, too. Though I have studied electrical engineering and physics extensively and done a lot of reading on the subject of batteries, I still don't feel like I have a 100% complete understanding of the best way to deal with battery charging, especially since the chemistry involved is always evolving. That said, I think there are five main enemies of the lifetime of current lithium ion battery technology:

    1. Heat: letting the battery heat up, and especially using the battery while it's hot is definitely detrimental to its longevity. My Pre Plus used to get fairly toasty while inductively charging sometimes, so it's something to watch when charging using that method. Playing a game or doing something else intensive while charging can also make the phone heat up.
    2. High voltage: yup, as far as I can tell, charging the battery fully is not in fact good for it. You obviously need to go for a full charge if you want to maximize battery life over a single discharge, but I think that doing so will lead to a more rapid degredation of the battery capacity over multiple charging cycles. I'm not sure if the battery manufacturers (or the makers of the charging circuit) take normal smartphone use into account when setting the charging parameters or not. Maybe they do something to compensate for the negative effects of prolonged high voltages.
    3. Deep discharge: using a lot of the battery's capacity is harmful to it. I don't know at what point in the discharge cycle it really starts to become a problem, but I just try to keep mine from going too low whenever possible.
    4. Usage of battery cycles: a Li-Ion battery is rated for a certain number of cycles before it loses a certain percentage of its capacity. This is a well known quantity, and you can look up graphs of capacity versus number of charge cycles for common batteries. A cycle is a full 100% discharge, but if you, say, use your battery repeatedly between 100%-95% (a hypothetical repetition of 5% capacity discharges with charging in between), you need 20 of those %5 usages to equal a full cycle. So in that sense it doesn't matter how often or how many times you charge.
    5. Time: Li-Ion batteries degrade over time, even if you don't use them, and that's just the way it is.


    So, as far as I can tell, an ideal usage scenario would be something fairly unrealistic like never discharging the battery below 60% and never charging it above 90% or something along those lines. I think the electric cars like the Tesla that use Li-Ion batteries actual have a charging/discharge cycle something like that to make the batteries last as long as possible, though those batteries are being used in a different way and are expected to last longer than those in smartphones. With my Galaxy Nexus I just charge it whenever possible, so it spends a lot of time in the high voltage state. I haven't worried about it because I know I could always pop in a new battery without breaking the bank. Now that I will be getting a DNA tomorrow, though, I'm thinking more about my charging strategy since the battery can't be replaced without some major surgery.

    I guess the important thing is to figure out which of the factors I listed above is the most detrimental and plan accordingly. As far as I cant tell, though, the general consensus seems to be that frequent charging is better than deep discharging, so I will probably keep trying to top off rather than letting the battery run down a lot.

    Edit: Here's the relevant summary straight from Battery University on how to prolong Li-Ion battery life:

    Of course this still leaves some question about the best way to treat the battery because we don't know exactly how the manufacturer of the device has chosen to report the percentages. If they are actually percentages of the full allowed voltage (either 3.6 or 3.7 V) then the 20-80% figure is accurate. However, if the percentages are scaled in some way then it won't be exactly right anymore. But the main point still stands: avoid 0% and 100% for best battery longevity. It would be nice if smartphones would come with the option to limit battery charging below 100% so that the phone can be left plugged in all night without harming the battery. Some laptops have that capability, as do some smartphones through custom kernels (Franco's kernel for the Galaxy Nexus has that option, I think).
    wow, great info, this is why i just dont get the decision to put the 2,020 in the DNA. It makes no sense!! (pun intended) Has anyone asked what the procedure for battery replacement is from HTC? at what point do they consider it "bad"? how long is "bad" covered?
  7. #7  

    Default Re: effects of constant on off charging?

    GEEEEEZ! Just enjoy your phone. How long are gonna have it, anyway! Chances are that your battery will be just fine whatever your charging habits. STOP WORRYING and charge at will! IMO All that stuff above is waaaaaay too much info for the common user. Just charge it and forget about it.
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  8. #8  

    Default Re: effects of constant on off charging?

    I've never had a battery go bad on me! I charge whenever possible! Techs can replace permanent batteries in five minutes!

    Sent from my EVO using Tapatalk 2
  9. #9  

    Default Re: effects of constant on off charging?

    On the software side, as far as I know, HTC automatically reduces the charging voltage as the battery goes over 90%. From there, I believe it slows to a crawl, even though it may show 100% on ur phone, it is really just somewhere between 90% to 100%. That's why, sometimes, when you first unplug ur phone and start using it, you will see what looks like a quick discharge, that's just the battery dropping down to 90% and finally reading correctly, it may have been at 91% or maybe 96%, but I believe that they rarely get to 100%. You've probably heard of people "bump" charging, which is tricking the phone to push the battery to 100% so it feels like you get better battery life, this has been mostly regarded as a bad idea for the same reasons being discussed here, but some people are still suggesting it every now and then.
  10. #10  
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    Default Re: effects of constant on off charging?

    Quote Originally Posted by droidman2177 View Post
    GEEEEEZ! Just enjoy your phone. How long are gonna have it, anyway! Chances are that your battery will be just fine whatever your charging habits. STOP WORRYING and charge at will! IMO All that stuff above is waaaaaay too much info for the common user. Just charge it and forget about it.
    I only plan to use it for a year or two, but one of my parents will probably continue to use it after that. I think the average smartphone loses around 10% of its capacity in one year and another 10% in the second year. If I can hand it off to my parents with a battery that's in better condition without going too far out of my way, then I will endeavor to do so.

    Besides, I don't consider myself a common user Readers of my post should feel free to take or leave the info.

    Sent from my Galaxy Nexus using Tapatalk 2
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    Default Re: effects of constant on off charging?

    Quote Originally Posted by Cattails_r_Edible View Post
    I've never had a battery go bad on me! I charge whenever possible! Techs can replace permanent batteries in five minutes!

    Sent from my EVO using Tapatalk 2
    I don't think it's so much of an issue of the battery going "bad" as it is an issue of the battery losing some of its capacity faster than it might if a little bit if care is taken.

    What you say about a tech replacing the battery intrigues me. Are you referring to a tech at say, a Verizon store, our somewhere else? Does that apply to a device like the DNA where the battery is buried between the PCB and the screen? I think that design requires substantially more disassembly. And what would be the cost for that sort of service?

    Sent from my Galaxy Nexus using Tapatalk 2
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    Default Re: effects of constant on off charging?

    Quote Originally Posted by JTNiggle View Post
    On the software side, as far as I know, HTC automatically reduces the charging voltage as the battery goes over 90%. From there, I believe it slows to a crawl, even though it may show 100% on ur phone, it is really just somewhere between 90% to 100%. That's why, sometimes, when you first unplug ur phone and start using it, you will see what looks like a quick discharge, that's just the battery dropping down to 90% and finally reading correctly, it may have been at 91% or maybe 96%, but I believe that they rarely get to 100%. You've probably heard of people "bump" charging, which is tricking the phone to push the battery to 100% so it feels like you get better battery life, this has been mostly regarded as a bad idea for the same reasons being discussed here, but some people are still suggesting it every now and then.
    Well that's interesting. I don't think the voltage can be reduced, though, because the charging voltage needs to be greater than that between the terminals of the battery in order for charge to be forced into the battery. Are you sure it isn't the current that's reduced to a crawl? I think that's how trickle charging works. As I understand it a Li-Ion battery is usually charged up to near its maximum voltage at a relatively fast rate, and then the charging curve has a long slow tail where current is slowly fed in and the voltage is gradually brought up to the maximum value. I'm really curious to know if HTC does not in fact slow the battery to reach the end of that long tail. That would yield nearly maximal short term battery life while extending the life of the battery in the long term.

    Sent from my Galaxy Nexus using Tapatalk 2
  13. Thread Author  Thread Author    #13  

    Default Re: effects of constant on off charging?

    do vzw techs swap out batteries on the razr series and iphones? i thought they were soldered leads. not to mention, would you want a vzw tech replacing it?
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    Default Re: effects of constant on off charging?

    I would like to think eventually someone will pull the DNA apart and make a video and/or documentation. There are so many smart/crazy/bored people today that love figuring these things out, and that is just helpful to everyone. So if that does happen, some handy folks can replace their own batteries and some shops/individuals can do it as well for those that don't want to chance it.
  15. #15  

    Default Re: effects of constant on off charging?

    Quote Originally Posted by njgsx96 View Post
    I would like to think eventually someone will pull the DNA apart and make a video and/or documentation. There are so many smart/crazy/bored people today that love figuring these things out, and that is just helpful to everyone. So if that does happen, some handy folks can replace their own batteries and some shops/individuals can do it as well for those that don't want to chance it.
    see post #10 - Why blame Verizon for the lack of SD card?
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    Default Re: effects of constant on off charging?

    There is no difference between maintenance charging your L-Ion battery 5 times a day (say from 80% to 100%) and full charging from dead phone once a day. High voltage, deep discharge, and heat produced will be harmful to all L-Ion batteries (industrial and consumer); however, those conditions relative to the setting. In a phone they are protected against. While your smart phone may say that your battery is charged to 100%, that certainly is not 100% of what the battery can take, that is 100% of the safe charge level. The phone is programmed to stop charging at a safe level. The same is true on the low end, you battery may show 20%, but that is not 20% of the max voltage, that is 20% of the safe level and your phone will shut off before harming the battery (or creating a deep discharge condition). As to the heat generated, in an industrial setting, a battery may be discharged in a matter of seconds, this would produce a ton of heat (and possibly harm). In a phone setting, the heat produced in charging/discharging is relatively low and should never be enough to cause harm.
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    Default Re: effects of constant on off charging?

    Quote Originally Posted by bellken View Post
    That looks like a very hard battery to replace. Much harder than on another sealed phone like the Nexus 4.

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    Default Re: effects of constant on off charging?

    Quote Originally Posted by Jdyount View Post
    There is no difference between maintenance charging your L-Ion battery 5 times a day (say from 80% to 100%) and full charging from dead phone once a day. High voltage, deep discharge, and heat produced will be harmful to all L-Ion batteries (industrial and consumer); however, those conditions relative to the setting. In a phone they are protected against. While your smart phone may say that your battery is charged to 100%, that certainly is not 100% of what the battery can take, that is 100% of the safe charge level. The phone is programmed to stop charging at a safe level. The same is true on the low end, you battery may show 20%, but that is not 20% of the max voltage, that is 20% of the safe level and your phone will shut off before harming the battery (or creating a deep discharge condition). As to the heat generated, in an industrial setting, a battery may be discharged in a matter of seconds, this would produce a ton of heat (and possibly harm). In a phone setting, the heat produced in charging/discharging is relatively low and should never be enough to cause harm.
    That all makes sense, but I would argue that "safe" is a relative term. The lower the maximum voltage (to a certain point), the longer the battery will be able to maintain a higher capacity. I think the battery charging circuit parameters are balanced for typical smartphone usage, and I'm certain that battery longevity could be improved for those who are concerned about such things by allowing the end user to lower the maximum charge level. It's one of those things that works well on average for most people who will be getting a new phone after a certain amount of time, but it is not ideal for all usage cases (for example, someone who is able to charge their phone multiple times per day and doesn't mind doing so if it means that their phone's battery will retain a higher capacity for those days when they choose to fully charge it because they won't be able to charge for the rest of the day).

    Regarding heat, plug-in charging is not likely to result in too much heat unless the phone is being intensely used at the same time. However, inductive wireless charging is inherently less efficient and does result in greater heat levels, sometimes to the point where the battery is negatively affected (that is, if it gets above 30 C).

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    Default Re: effects of constant on off charging?

    Safe is not a relative term, per IEEE Standards.

    http://files.ctia.org/pdf/CTIA_Battery_PMD_Rev_5.3.pdf

    The CTIA (Cellular Telecommunications and Internet Association) has developed a certification program for validating compliance to the IEEE 1725-2006 standard via a combination of audits and testing. The standard establishes criteria for design analysis to ensure reliable user experience and operation of rechargeable lithium ion and lithium polymer batteries for cellular telephone applications.

    IEEE 1725-2006 encompasses system integration, battery cell design process, manufacturing considerations, assembly precautions, leakage protection, component and thermal considerations,overcharge, overcurrent, mechanical considerations, connector & terminals, quality control, security and validation, as well as external influences such as the host and auxiliary devices including AC & DC adapters.
    Last edited by Jdyount; 11-29-2012 at 02:56 PM.
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    Default Re: effects of constant on off charging?

    Quote Originally Posted by Jdyount View Post
    Safe is not a relative term, per IEEE Standards.

    http://files.ctia.org/pdf/CTIA_Battery_PMD_Rev_5.3.pdf

    The CTIA (Cellular Telecommunications and Internet Association) has developed a certification program for validating compliance to the IEEE 1725-2006 standard via a combination of audits and testing. The standard establishes criteria for design analysis to ensure reliable user experience and operation of rechargeable lithium ion and lithium polymer batteries for cellular telephone applications.

    IEEE 1725-2006 encompasses system integration, battery cell design process, manufacturing considerations, assembly precautions, leakage protection, component and thermal considerations,overcharge, overcurrent, mechanical considerations, connector & terminals, quality control, security and validation, as well as external influences such as the host and auxiliary devices including AC & DC adapters.
    I just read through the IEEE 1725-2006 standard. Thanks for bringing it to my attention, as it was quite interesting. However, I think you misunderstood my usage of the word "safe". The IEEE standard in question dictates all kinds of manufacturing methods and testing procedures to ensure that batteries will not catastrophically fail or injure a user. That's all well and good, but what I meant by "safe" for the battery is charging practices that will maintain the battery's capacity for a long time without unreasonably sacrificing convenience or performance.

    I'm sure that the charging circuits in today's smartphones are fine for preventing batteries from exploding or failing in a week's time, but I remain unconvinced that they use charging algorithms that optimize for battery capacity longevity over short-term (like one day) capacity. I think it's entirely up to the battery/phone manufacturers whether to, say, charge the battery to 95% or 100% of its full voltage capacity. Charging to 4.1 V rather than 4.2 V results in a run time that is about 10% shorter, but it can make the battery retain its capacity over nearly twice as many charging cycles. Moving to an even lower maximum voltage sacrifices even more run-time from a single charge while allowing the battery to remain useful for even longer.

    I would imagine that the maximum voltage that is used is calculated to maximize single charge run time while still maintaining x% of battery capacity after the average amount of time that a user keeps using a phone, which in the US is likely right around two years.

    My point is that it would be nice if the end user were given the option to tweak that maximum voltage in order to extend the overall life of the battery when maximum single charge capacity is not necessary (i.e. a charger will be available during the day). However, given that such a parameter is implemented in a low-level IC somewhere in the charging circuit, I don't know if it would be reasonable to expect a manufacturer to provide a way to change that number. My thinking is that it shouldn't be too hard, though, given that the custom kernel I am running on my Galaxy Nexus enables the ability to change that parameter.

    At the very least there could be two options exposed to the end user: one option for maximum daily run time and another option for less daily run time but greater battery longevity. That would keep it simple for the average user but also give a bit more control to those who want it. This is less of an issue for those who throw away their phone after a year or two or don't mind buying a new battery, but for those who want the battery to last longer or can't replace the battery it's more of an issue.

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    Default Re: effects of constant on off charging?

    The standard not only protects against poor manufacturing, it ensures reliable user experience. These phone batteries are designed to be charged to their 100% setting and protected, under IEEE 1725 Standards, to prevent over charge and over current.

    Now, in reading the article about prolonging lithium battery life on the battery universe website:

    Sure you can increase the number of charge cycles in a battery by lowering the max charge level, but the info can be somewhat misleading because you should have more charge cycles if you decrease your depth of discharge. You can charge from 0% to 50% twice as many times as you can charge from 0% to 100% (50 X 2 = 100).

    According to that article, if your depth of charge is 50% then you should get 1200 to 1500 cycles. I would guess that most users charge once a day and plug in to charge at night somewhere between 75% and 50% battery life. That is 3.3 to 4.1 years.... Even if you half that, you're still around the 2 year mark (which is where most would get a new phone). Now you are correct, if you do to math and factor out the lowering depth of charge gain, you can increase the amount charge cycles by decreasing the max voltage; but, this will only effect people who plan on using the same phone for 5 years. I would argue that your micro USB port won't last that long anyway.

    The point I want to emphasize is that for 99.9% of people, they would be wasting their time monitoring the max charge, unplugging at 60% or 80% every time they charge. Under all but extreme use conditions, these phone batteries are made to exceed the 2 year cycle in which most people use a phone. Now I will concede that if you have a battery eating phone like the T-Bolt, the battery won't last 2 years, but thats not the fault of the battery.....
    Last edited by Jdyount; 11-30-2012 at 11:37 AM.
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    Default Re: effects of constant on off charging?

    This has turned into one of the most informational battery threads I have ever seen. Thanks guys!
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    Default Re: effects of constant on off charging?

    Quote Originally Posted by Jdyount View Post
    The standard not only protects against poor manufacturing, it ensures reliable user experience. These phone batteries are designed to be charged to their 100% setting and protected, under IEEE 1725 Standards, to prevent over charge and over current.

    Now, in reading the article about prolonging lithium battery life on the battery universe website:

    Sure you can increase the number of charge cycles in a battery by lowering the max charge level, but the info can be somewhat misleading because you should have more charge cycles if you decrease your depth of discharge. You can charge from 0% to 50% twice as many times as you can charge from 0% to 100% (50 X 2 = 100).

    According to that article, if your depth of charge is 50% then you should get 1200 to 1500 cycles. I would guess that most users charge once a day and plug in to charge at night somewhere between 75% and 50% battery life. That is 3.3 to 4.1 years.... Even if you half that, you're still around the 2 year mark (which is where most would get a new phone). Now you are correct, if you do to math and factor out the lowering depth of charge gain, you can increase the amount charge cycles by decreasing the max voltage; but, this will only effect people who plan on using the same phone for 5 years. I would argue that your micro USB port won't last that long anyway.

    The point I want to emphasize is that for 99.9% of people, they would be wasting their time monitoring the max charge, unplugging at 60% or 80% every time they charge. Under all but extreme use conditions, these phone batteries are made to exceed the 2 year cycle in which most people use a phone. Now I will concede that if you have a battery eating phone like the T-Bolt, the battery won't last 2 years, but thats not the fault of the battery.....
    Good points, all around. I agree with you that the IEEE standard ensures both safe batteries/chargers and reliable operation, but I am still of the opinion that the word "reliable" is used in this case to mean "won't explode in your face or fail prematurely for an average user". I did not see anything in the document about ensuring the battery will maintain a certain percentage of its capacity under specific conditions for a specific period of time. The stuff about preventing overcharge and overcurrent conditions and whatnot is more of an "explode in your face" issue than a "keep your battery going strong for many years" issue, in my opinion.

    I absolutely agree with you that decreasing the depth of discharge will lead to better maintenance of battery capacity over more charging cycles. That said, I think you might be greatly overestimating the amount of battery life most people have left when they plug in at night (at least for those people using Android devices whose names don't end in Maxx). Also, here's something that I didn't realize was confusing me until just now: does depth of discharge merely refer to the percentage of battery life that is expended between charges, or is it the amount by which battery life percentage falls below 100%? I had always thought it was the latter, but now you have me wondering if I am wrong about that. If my interpretation is correct, then your example of charging 0%-50% would be much worse for the battery than the alternative of charging 50%-100%.

    Regarding lowering the maximum voltage, I agree that it would be ridiculous to expect anybody to carefully monitor their charging status at all times and unplug when they reach 80% or whatever. But what I was suggesting is that there ought to be a setting to automatically limit that maximum voltage without the user having to do anything other than choose "battery longevity mode" over "maximum run time mode" or something along those lines. For example, Franco's GNex kernel has a battery saving option that allows you to set a maximum percentage above which the battery will stop charging with no intervention from the user. The optimum conditions for the battery should, as I understand it, involve both preventing deep discharge and limiting the maximum voltage. If you only discharge your battery by 5% every time but that range fits in between 95% and 100% of the battery's full charge capacity then you're avoiding the deep discharge, but your're still sitting in that high voltage range.

    I don't think a USB port should have any trouble lasting for five years. I don't have a source handy, but I believe that micro USB ports are built to withstand a minimum of 10,000 insertions. That means you could plug/unplug your phone more than 5 times a day for 5 years, so I doubt it would fail mechanically in that period of time. Of course that doesn't account for other factors like corrosion, etc. But hey, that's what that stupid little flap on the bottom of the DNA is for, right?!
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    Default Re: effects of constant on off charging?

    The study rates number of cycles based on depth of discharge (dod) and included incremental percentages. My interpretation would be that they were starting from 100% charge, the measuring dod based on percent from there. My example was to show simply that one full charge cycle and 2 half charge cycles are essentially equivalent. Now, there would be a slight difference in charging from 0% to 50% and charging from 50% to 100% because the latter is taking you to max.

    As to the USB, I do agree, in rated use, 10,000 insertions sounds right, but that doesn't account for life. For kids or dogs knocking your phone off the table while charging, for trying to get the cable in the right way in the dark, ect.... In my personal use, I've found after about two years, the micro usb port becomes wore (cables are loose, sometimes doesn't charge).

    Having a customer kernel is a great option and having those battery mode settings are great and I'm sure they help, but not everyone roots.

    As to battery life, I would like to see stats on that. I can tell you with my DNA, unless I've play games for a couple of hours, I haven't been below 70%. Right now (8 hour day so far), I'm at 87%. With my T-bolt, it was dead at 10 hours no matter what. My wife charges her iPhone (yes I know, boo) every other day.

    You have had very good points, and I appreciate the discussion.
  25. #25  

    Default Re: effects of constant on off charging?

    Ditto on the great battery info from the posters, but in regards to the op who are 'they keep telling me' ... just charge overnight and use the phone, many people won't need a recharge during the day, of course some will but then plug it in.. Power Management has alot to do with power consumption and HTC seems to have done a fair job at it this time.
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