Battery dead? This is for all you naysayers...

[Skull One]

Skull One, I respect your knowledge and from the perspective that you are speaking (that of one who knows how to properly maintain a LIPO battery), the information you present is accurate. In other words, is it safe to discharge to 0%? Sure IF you have practiced "save charging", or in other words, if the battery and the phone are on the same track, if the battery is REALLY AT 3V when the phone reads 0%.

The problem is that is not the actual experience for many on the threads, and probably even more who aren't. There have been plenty of examples of people who have discharged their batteries so low, by relying on levels indicated by the meter when in fact the meter is out of calibration, that they've pushed the batteries to near protection mode, at worst, and under the levels needed to sustain a proper boot sequence while connected to the charger at best.

So to say empirically that it's safe to discharge to 0% is to assume that everyone's phones and batteries are properly in sync and the level readings are accurate. This is simply not the case.

I don't disagree with your information, and God knows I've read all the same information you put up here previously, and some on the threads know I've put up similar, perhaps less technical information which says the same. But to say to everyone it's OK to drain to 0% is to invite a lot of unresponsive phones.

In response to your disagreement of my comment about discharging to the low battery flag, rather than to 0% ("That is technically incorrect. A full discharge is the only way to reset batterystats.bin's data to show what the lowest voltage is before full shut off." ), please see the following from BatteryUniversity.com (whom you also quoted and I would bet have gotten at least a portion of your knowledge from)>

Manual calibration is possible by running the battery down until “Low Battery” appears. This can be done in the equipment or with a battery analyzer. A full discharge sets the discharge flag and the subsequent recharge the charge flag. Establishing these two markers allows SoC to be calculated by tracking the distance between the flags. For best results, calibrate a device in continuous use every three months or after 40 partial cycles. If the device applies a periodic deep discharge on its own accord, no additional calibration will be required. Figure 1 shows the full-discharge and full-charge flags.

View attachment 48511
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You will note that the full discharge flag is at 10% by the illustration above, and is described as "until “Low Battery” appears". For Motorola Droid RAZR phones, that indicator appears not at 10%, but at 15%, which is why I maintain that 15% should be considered the low threshold for most users. Will I let my phone go below 15%? Sure, I've done it. Will I let it go to 0%? Not if I can help it, however I know that my battery is properly calibrated to the phone's meter, so even if I do accidently let it go to 0% (*as did last night*), I will still be able to get the phone to start the charging process properly and will successfully charge and not get stuck in a boot loop due to depressed battery voltage. Would I recommend that for ANYONE else? Heck no.

To summarize, I believe we're both in agreement generally, but where I choose to differ is in the advice given. Although the advice may be technically right, sometimes it's wise to err on the side of caution - especially where it involves the masses. I don't want to be held responsible for someone essentially killing their phone due to following my advice, so I will remain convinced that 15% should be the signal to start looking for a charger, if for no other reason than because that's what the text on the phone says.

I am very aware of the condition you speak of, but the Android OS periodically checks the actual voltage level against the predict voltage level and tweaks the data points in real time. As you approach 0% in the OS, it checks it against the 2.7v standard (or if the manufacture chooses a higher voltage) and then knows to reset that final data before shut off. Your overshoot scenario isn't possible if the user is watching the phone as it turns itself off and then respond by placing the phone on the charger.

BTW, some of the newer phones are now being made with trip outs above 2.9v on purpose to avoid your scenario. Because they know the average teenager is going to use their phone till it drops dead at least 3 times a week.

Cell phone manufactures would be dealing with a LOT of warranty claims if they didn't account for your condition and the teenager experience.

 

[FoxKat]

I am very aware of the condition you speak of, but the Android OS periodically checks the actual voltage level against the predict voltage level and tweaks the data points in real time. As you approach 0% in the OS, it checks it against the 2.7v standard (or if the manufacture chooses a higher voltage) and then knows to reset that final data before shut off. Your overshoot scenario isn't possible if the user is watching the phone as it turns itself off and then respond by placing the phone on the charger.

BTW, some of the newer phones are now being made with trip outs above 2.9v on purpose to avoid your scenario. Because they know the average teenager is going to use their phone till it drops dead at least 3 times a week.

Cell phone manufactures would be dealing with a LOT of warranty claims if they didn't account for your condition and the teenager experience.

OK, once again, I agree with you in theory but in the real world scenario people are having these phones die overnight, possibly only a short time after they've gone to sleep, or sometime during the day without "watching the phone as it turns itself off and then...placing the phone on the charger" [within a reasonable amount of time from when the phone shuts down]. The result is their batteries continue to discharge over the following hours and voltages continue to drop as time wears on. So by the time they realize it, the phone will not even take a normal charge (solid or flashing white light), because the combination of the deep draw of the undercharged battery from the charger along with the high demand of the phone for power upon power-up leaves insufficient voltage and amperage to turn the ole' thing over. Instead they both fight for the limited voltage and current and get nowhere.

What we have to remember here on these forums, perhaps more than anything else is that people look up to us for advice, but more importantly HELPFUL advice, or advice that isn't going to lead them to potential disaster. Even though there is a comparably high percentage of tech-savvy individuals on these forums versus the general populous, there is still potentially tens or even hundreds of thousands of attendees over the course of a year who are far less savvy (the greater percentage). You call them the "average teenager", but I say simply people who expect these phones will be completely dummy-proof, like their former "flip phones" or their iPhones or Blackberry's...problem is they're not.

To go even further, we then have a large community of people who delve into rooting, and then further into flashing of ROMs, and still further into overclocking, deleting of system apps, etc. The list goes on and on. These people may be prepared for the worst for the most part, but there's always the guy or gal who never had an Android phone, let alone never rooted or flashed, watching all the chatter and before you know it - 2 days after they bought the phone, they're talking about it, and then a day later they've bricked it and then we spend hours and countless messages back and forth trying to throw them a lifeline. I'd rather they would learn a LOT slower and take a LOT longer before taking the plunge if at all. If it were possible, perhaps they should have to study and pass a test before being allowed into the hacks forum...(not really, but I digress).

The information where the "trip out" voltage is set on these Motorola RAZR phones isn't common knowledge, and frankly I don't know the actual voltage either but I have read enough to believe it's probably 3V or damn close. At that voltage, the phone can rest without a charge for an extended period of time, possibly a day or more, but the problem is that just because the cutoff voltage is 3V, doesn't mean it can't fall further faster. It all has to do with the health of the battery and that dictates the rate of slope from 3V to 2.5, and to protection mode. If it's a healthy battery, it will slope off slowly, but if the battery isn't healthy due to the "teenager experience" (pardon the terminology - I didn't coin it, just borrowed it), the battery's slope could be a very slippery one, resulting in the problems we've seen a rash of this past few weeks (i.e. boot looping, power cycling, failing to charge, white lights, etc.).

I remain convinced that we should be advising people to place their phones on charge as soon after the "low battery" flag is set (i.e. 15%), as possible, and that they should do a full charge to 100% with the phone powered off about once every 60-90 days but at least after every 40 complete cycles of the battery. I also recommend that after that 100% powered-off charge they should then use the phone until the 15% low battery flag, and then once again charge with the power off to 100%. If they follow that regimen, they are highly unlikely to suffer the symptoms of a deeply discharged battery and the unpleasant consequences.

:icon_exclaim:

*EDIT*: Also, since you weren't here for all the previous threads, I have another issue I wish to bring up. That's the one where the WOW factor overrides the manufacturer's instructions and people use their phones right out of the box without first fully charging them with power off. This sets off the entire series of events that ends in the unfortunate fail of the phone, by being unwilling to take a charge or one of the other symptoms mentioned. Again, perhaps we'll call it the "WOW" effect, but it's a problem just the same.

I'd like to poll the entire forum community and ask everyone how many actually powered off their phone immediately after activation at the Verizon Phone Center Store and placed it on a charger while off, allowing it to charge to 100% before using it. Or how many who received the phone in the mail immediately did the same charging sequence instead of powering the new toy up and playing with it to their heart's content. I would be willing to bet it is dramatically lower than 50% who actually DO what the manufacturer says to DO. I say that the greater percentage of these "dead batteries" is as a direct and eventual result of that very first failure.

 

[Skull One]

You make an very interesting point about being "politically correct for the greater good".

So in your opinion, based on observational data, a phone manufacturer has broken one of the cardinal rules of electrical engineering. You are now going to proceed by giving advice to the masses to help them maintain the "status quo" instead of letting the phone maker pay for the warranty issue their bad design created, which would in turn get them to fix the software and firmware properly since that is cheaper than dealing with warranty claims.

That is a very interesting stance to take.

 

[FoxKat]

You make an very interesting point about being "politically correct for the greater good".

So in your opinion, based on observational data, a phone manufacturer has broken one of the cardinal rules of electrical engineering. You are now going to proceed by giving advice to the masses to help them maintain the "status quo" instead of letting the phone maker pay for the warranty issue their bad design created, which would in turn get them to fix the software and firmware properly since that is cheaper than dealing with warranty claims.

That is a very interesting stance to take.

You can read my advice as whatever you want to. I am surely not excusing any manufacturer for breaking any cardinal rules, and I'm also not blaming any manufacturer for the same. As far as being politically correct, if that is how you see it, I'm OK with that.

Truth is, the instructions included with the phone tell us all we need to know, but it's the human nature to want to explore and to seek instant gratification, so the typical phone buyer is going to ignore the instructions and jump right in. They're going to use it for as long as they can, and they're going to suffer the consequences of their own actions, and then they're going to take the phones back when they fail and place unfounded warranty claims, and drive themselves to frustration along with driving prices up in the process. Then they will go back and do it again. And after 2 or 3 or 4 replacement phones there going to post "this phone sucks" threads.

Promoting that modus operandi, and calling the failures a manufacturer's defect, and suggesting that through some miracle the manufacturer is going to listen to the complaints, take responsibility for the "failures" and "fix" the phone for the benefit of all is a pipe dream.

I'm not saying that a fix isn't necessary or that one won't come, but what about all the users who suffer in the process? The problem with that philosophy is that a whole lot of people will be disappointed and give up after trying incessantly to make the phone work "normally", and some will take the opportunity to bash.

Neither of those results will be productive, neither will promote a community atmosphere, and neither will add to the user experience. Perhaps I have a "different" view of the forums' purposes.


Sent from my DROID RAZR using Tapatalk

 

[SallyC]

I went to public skool, so most of this stuff is way over my head. That said, this is a very interesting discussion. Thanks!

I'm just bummed I don't get to sell tickets.

 

[FoxKat]

I'm just bummed I don't get to sell tickets.

Question is are you here just to sell tickets or to enjoy the game? :icon_eek:

If you're here to enjoy the game, which team are you rooting for?

 

[FoxKat]

But how can the meter have a true eye for the capacity of the battery if you do not show it that the capacity is decreasing by never fully discharging the battery?

Sent from my DROID BIONIC using DroidForums

There is a unique characteristic of LIPO (Lithium Ion Polymer) batteries, which causes their discharge slope to look very strange. For most batteries, the voltage drops relatively steadily from a full charge to near 0 capacity, however with LIPO batteries, the voltage drops from the full charge level of 4.2V to about 3.8V to 4V rather quickly, or from 100% to 80% of capacity in far less than 20% of the total time it's used (one reason why people may notice their meter dropping from 100% to 90% in a very short period of time after unplugging), but then it remains relatively flat at or near 3.8V to 4V for the bulk of the remaining capacity, the next 60% or so of capacity. This makes it VERY difficult for the meter to accurately represent relative capacity during this range from 20% to 80%. Therefore it relies on previous full discharge and recharge cycles combined with voltage and current draw readings along the way to "estimate" the remaining capacity.

Then it begins to slope off again and drop rather quickly from about 20% of capacity to 0% of capacity. This is why the reset flag for low battery is set at 15%. By the time it has reached 15%, the slope is strong enough for the metering system to recognize the discharge pattern and accurately calculate how much longer until 0%.

Think of a battery in these terms. The true 100% capacity of a battery is from max voltage (in this case 4.2 Volts is a safe max) to 0 voltage which would be a completely discharged and totally unusable battery. The problem is that even a battery with 2 Volts remaining is completely unusable as well since it can never take a charge again.

See the illustration below.


View attachment 48519



What that illustration is showing you is that 100% of capacity is not the same thing as 100% of battery voltage available. In fact, what you read as 100% charge is only the top 70% or so of the battery's total storage. The problem is that these LIPO batteries can not be discharged below a certain voltage - usually about 2.5V to 2.7V or they go into a self-protection mode and essentially shut down. There is a way to wake most of these protected batteries up again but it can't be done with the chargers supplied by the phone manufacturer. Perhaps the above illustration should actually represent the meter as 100% to 0% (green to dark) and 0% to -30% (red) where the -30% is the area that can never be used.

Another problem is that once powered off at 0%, there still needs to be enough voltage in reserve so that when you plug in the charger it can start or activate the charging circuitry and also begin charging the battery. Somewhere between 3V and 2.5-2.7V is a voltage that is too low to be able to support the boot process while connected to a charger, yet not so low to trigger the protection mode of the battery. This can result in boot looping or "power cycling", and also errors on boot, as well as a white light on the front of the phone that either shines solid or flashes to indicate it doesn't have sufficient voltage to start. This is also used to indicate a battery that is no longer able to take a charge and needs replacing.

So to prevent you from reaching that protection mode, and also to ensure the battery has enough voltage to allow your charger to kick start it while charging and also activate the phone's charging circuitry (or to avoid the low voltage boot looping state), the manufacturer of the phone sets the phone to shut down completely when the battery voltage reaches about 3.0V (or 0% on your battery meter). There is still power in the battery but it is essentially unusable due to the protection circuitry. So when your meter reads 50%, it's not 50% of the total battery capacity, it's 50% of the safely usable capacity, which is the top 70% of the total capacity. This is why it is dangerous to discharge to 0% of usable capacity, since if your meter is not properly calibrated to the battery's unique charge/discharge signature it might actually dip too far below the necessary voltages required to allow the charging to start properly, or into protection mode - essentially rendering the battery useless.

 

[SallyC]

Question is are you here just to sell tickets or to enjoy the game? :icon_eek:If you're here to enjoy the game, which team are you rooting for?

Hey, I'm a mother (and grandmother)! Trust me, I can sell tickets and enjoy the game!! My team bias is not too hard to guess, but, like a certain moderator, I have to admit I find some threads

opcorn:Fun and entertaining...

View attachment 48523

 

[FoxKat]

Hey, I'm a mother (and grandmother)! Trust me, I can sell tickets and enjoy the game!! My team bias is not too hard to guess, but, like a certain moderator, I have to admit I find some threads

Fun and entertaining...

That's more like it!! :rockon:

 

[thaDroidz]

Yep looks as if this pages are fool of knowledge ...
Well at least from my perspective sitting in the back of class playing on my DROID! !

----posted maxx'ed out----

 

[FoxKat]

Yep looks as if this pages are fool of knowledge ...
Well at least from my perspective sitting in the back of class playing on my DROID! !

----posted maxx'ed out----

Ahem...did you mean "full" of knowledge or "fool" of knowledge? I don' t know whether to be proud or sad. :blink:

 

[thaDroidz]

Lol...
I did mean full, noticed it after the fact. Was about to edit but kinda made me chuckle so I left..



----posted maxx'ed out----

 

[jp233]

I'm going to have to try short bursts of charging - mine won't last a full work day. I have to put it on airplane mode during the day at work since I don't get a signal and it will drain quickly while I'm there. And then using it commuting home (normally on the phone), and using data services at home during the evening - it will generally get to 15% battery every evening. Normally I let it charge all night (power on), because I also use it as an alarm. Maybe I'll have to dust off the actual clock alarm and use that every few days, and let the phone either sit OFF all night, and try to do a full charge less often.

 

[FoxKat]

I'm going to have to try short bursts of charging - mine won't last a full work day. I have to put it on airplane mode during the day at work since I don't get a signal and it will drain quickly while I'm there. And then using it commuting home (normally on the phone), and using data services at home during the evening - it will generally get to 15% battery every evening. Normally I let it charge all night (power on), because I also use it as an alarm. Maybe I'll have to dust off the actual clock alarm and use that every few days, and let the phone either sit OFF all night, and try to do a full charge less often.

There is information that indicates you can extend the life of a Lithium Ion Polymer battery by charging more frequently and not charging long and full charging cycles as a habit.

This information is from BatteryUniversity.com

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.
Table 2 compares the number of discharge/charge cycles a battery can deliver at various DoD levels before lithium-ion is worn out. We assume end of life when the battery capacity drops to 70 percent. This is an arbitrary threshold that is application based.

Depth of discharge​	Discharge cycles​	Table 2: Cycle life and depth of discharge A partial discharge reduces stress and prolongs battery life. Elevated temperature and high currents also affect cycle life.
100% DoD​ 50% DoD​ 25% DoD​ 10% DoD​	500​ 1500​ 2500​ 4700​

Specifying battery life by the number of discharge cycles is not complete by itself; equally if not more important are temperature conditions and charging voltages. Lithium-ion suffers stress when exposed to heat and kept at a high charge voltage.

By looking at the chart, it seems the sweet spot, or most life overall is achieved by charge cycles that are close to 50% of capacity on average (50*1500=75,000), versus 100% charge cycles (100*500=50,000). I would have liked to see the chart extended into 10% ranges but it also proves that 25% charges and discharges also provide a longer life than 100% charge cycles (25*2500=62,500), so it is safe to assume that charging somewhere between 25% and 75% as regular cycles on average is likely to be yielding the best overall performance over life.











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[Xproplayer]

There is information that indicates you can extend the life of a Lithium Ion Polymer battery by charging more frequently and not charging long and full charging cycles as a habit.

This information is from BatteryUniversity.com

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.
Table 2 compares the number of discharge/charge cycles a battery can deliver at various DoD levels before lithium-ion is worn out. We assume end of life when the battery capacity drops to 70 percent. This is an arbitrary threshold that is application based.

Depth of discharge​	Discharge cycles​	Table 2: Cycle life and depth of discharge A partial discharge reduces stress and prolongs battery life. Elevated temperature and high currents also affect cycle life.
100% DoD​ 50% DoD​ 25% DoD​ 10% DoD​	500​ 1500​ 2500​ 4700​

Specifying battery life by the number of discharge cycles is not complete by itself; equally if not more important are temperature conditions and charging voltages. Lithium-ion suffers stress when exposed to heat and kept at a high charge voltage.

By looking at the chart, it seems the sweet spot, or most life overall is achieved by charge cycles that are close to 50% of capacity on average (50*1500=75,000), versus 100% charge cycles (100*500=50,000). I would have liked to see the chart extended into 10% ranges but it also proves that 25% charges and discharges also provide a longer life than 100% charge cycles (25*2500=62,500), so it is safe to assume that charging somewhere between 25% and 75% as regular cycles on average is likely to be yielding the best overall performance over life.











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I'm sorry but could you put that in more layman terms? From what I understood you recommend plugging the phone in when it is in 25-75% battery, is this correct?