Database Users

Some battery thoughts and testings..

Ok, so my battery can go from 100% full charge (overnight) to like 96% within first couple of minutes. I've done the plug/pull trick and it seems to help for a very short while and it will go back to same issue again and again.
Recently, I just bought the $10 2 batteries with external charger pack and had the extra el cheapo battery all charged up using the external charger. To my surprise, I found that the battery charged with external charger drain very accurately.
I've done some testing for a couple of days now by basically draining out the battery and replace it with a fresh one from the external charger without using the wall adapter.
So my thinking is when charging with wall charger, I think the phone does not evenly charges the battery cells because there are so many moving parts while the phone is on and charging. Therefore, it causes the cell to be charged unevenly that leads to quick battery drain.
With the external charged battery, I went from 100% to 90% in 6 hours time with light usage and GPS on.
Give it a try to see if you get different experience with your battery.

I have been doing the same these past couple of weeks (ever since I rooted my 2.2).
My external charger will be here today (it's now saturday morning cst) and I ordered it yesterday. Gotta love amazon one day shipping.
So far I have observed some very interesting charging habits the evo displays when charging with it's included wall charger and stock and extended batteries.

i went 3 days 12 hours and 46 minutes on a single charge, that is with using the stock battery and a regular wall charger, yes i'm rooted and i used setcpu to set my frequency to 614 when screen on, and 245 when screen off, at night when i go to sleep i put the phone into airplane mode, and overall usage was cut back to light to moderate usage, i was trying to see how long i could actually go on the stock battery, and i must admit i'm very impressed.
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I think the general concensus was that the phone doesn't trickle charge. It will hit full then stop charging to a point then will charge again, all while saying 100%
I charged to full then while plugged in it range gps and iheartradio for 20 minutes, unplugged and it dropped to 92 within 5 minutes

Same here. I'll unplug it, browse the web while eating breakfast (about 10/15 minutes) and today I dropped to 89%. But its been two hours since then with some light texting and more browsing im now at 80%.

pinoyxpryde said:
I think the general concensus was that the phone doesn't trickle charge. It will hit full then stop charging to a point then will charge again, all while saying 100%
I charged to full then while plugged in it range gps and iheartradio for 20 minutes, unplugged and it dropped to 92 within 5 minutes
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Click to collapse
granted be the trickle charge is with using the stock usb connecter style wall charger right, i never use that thing unless im connected to the pc, i have a actual regular wall charger that came on another phone i used to have before my Evo, lol.

Update: Yep this morning I replaced my battery that was charged by the external charger that I bought with the bundle and same result. On average, my battery drains at the rate of 1.5% per every hour on light usage with GPS on.
I think from now on, I won't charge the phone using the default charger overnight.

vboyz103 said:
Update: Yep this morning I replaced my battery that was charged by the external charger that I bought with the bundle and same result. On average, my battery drains at the rate of 1.5% per every hour on light usage with GPS on.
I think from now on, I won't charge the phone using the default charger overnight.
Click to expand...
Click to collapse
So you take your battery out at night and charge it with an external charger?

Leaving the battery charging all night is bad for the batteries lifespan, that is why htc and many laptop companies implement this feature.
Stop complaining about it. Its only one cell and it has nothing to do with evenly charging, its regulated by the onboard charging system.
Sent from my PC36100 using XDA App

lehalter said:
So you take your battery out at night and charge it with an external charger?
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Click to collapse
No I have 2 batteries, and I used one of them throughout the day including leaving it overnight uncharged, then in morning I swap it out with the one that was fully charged from external charger.

mastermarc said:
Leaving the battery charging all night is bad for the batteries lifespan, that is why htc and many laptop companies implement this feature.
Stop complaining about it. Its only one cell and it has nothing to do with evenly charging, its regulated by the onboard charging system.
Sent from my PC36100 using XDA App
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LOL, I found this statement is bogus because if you don't leave it charged up overnight then what do you do to recharge it? Come on man! Batteries are meant to be charged up over a period of time.
I'm not saying my understanding of uneven charge distribution is rock solid, but at least I backed it up with some of my own studies.

I just always do my overnight charge with the phone OFF.
Sometimes in the morning I'll also do the unplug, re-plug, wait for green trick.
As long as I don't use 4G, my battery life is GREAT.
My 4g consumption is probably worse because I've tweaked the settings to retry more often - default was 5 minutes between retries.
I guess for people that get calls late at night or don't have a home land-line, turning it off at night is not feasable. But it does get around that immediate drop problem.

They charge at a near constant rate until they are full, after that it is BAD to continue topping them off, please do some research on lithium charging techniques as your "testing" clearly hasn't taught you much if anything about the chemistry.
Sent from my PC36100 using XDA App

mastermarc said:
They charge at a near constant rate until they are full, after that it is BAD to continue topping them off, please do some research on lithium charging techniques as your "testing" clearly hasn't taught you much if anything about the chemistry.
Sent from my PC36100 using XDA App
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Lol you clearly have no idea what you are talking about. The phone doesn't charge at a constant rate until it's full. It would be disastrous for LiCo chemistry if it maintained 0.66C up until it hit 100%. The cell would cook itself to death.
The correct charging profile for the Evo is that it charges constant rate till it hits like 70%, then it slows down until it finally hits 100% and then the charging cuts off. Download JuicePlotter and completely discharge and charge your phone to see this.
Hypothesis below:
The problem with the Evo is that once it hits that cut-off point, the phone never again seems to check if the battery is actually full. (LiCo chemistry has a slight tendency to settle a few hundredths of a volt after charging, and a few hundreths means a couple of %age points when you're in the 4.1V+ range) whereas most cheap chargers will actually keep checking the voltage and trickle charging if necessary.

Too much hassle to keep changing batteries in the Evo, would have to take my case off then the back cover is kinda a ***** and feels like its going to break a tab off or something. The immediate drop doesn't bother me too much. I just use my car charger and it tops me off usually.
Sent from my PC36100 using Tapatalk

Yes, you are right about switching at 70%. Didn't want to complicate things since we got some novices here clearly.
The hypothesis, not so much...as I said before its intentional and it does what it does to preserve the lifespan of the battery. If you paid $10 for a chinese battery, who cares about lifespan, just use an external charger.
Charge it when its off and it gets and stays at 100. Direct evidence that what they did was a feature and not a mistake.
Sent from an evo

I been using the 700 mah charger and I've haven't noticed any difference in performance. Also again I lost 9% carge in the 10 minutes I was surfing while eating breakfast. Oh well. Im not leaving my computer on all night sucking 400 watts or more to charge a 5 watt phone lol. Ill deal with the 10% drain.

Those are the critters under your bed, they use your phone while u r asleep.
Sent from my PC36100 using XDA App

mastermarc said:
The hypothesis, not so much...as I said before its intentional and it does what it does to preserve the lifespan of the battery. If you paid $10 for a chinese battery, who cares about lifespan, just use an external charger.
Charge it when its off and it gets and stays at 100. Direct evidence that what they did was a feature and not a mistake.
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Click to collapse
I build and design Lithium battery based systems for a living. There's absolutely no reason not to top off the battery. The recommended way to charge any Lithium cell is to constant-current charge and then constant-voltage charge up to 4.2V. Once you get to 4.2V, there's nothing wrong with charging it back up if it settles a little. In fact, most chargers don't even "terminate", they just hold 4.2V.
As for your assertion that it is not a bug, did you consider that perhaps the kernel designers are not realizing that there is some kind of parasitic drain on the battery once the kernel thinks it is full?

AzN1337c0d3r said:
I build and design Lithium battery based systems for a living. There's absolutely no reason not to top off the battery. The recommended way to charge any Lithium cell is to constant-current charge and then constant-voltage charge up to 4.2V. Once you get to 4.2V, there's nothing wrong with charging it back up if it settles a little. In fact, most chargers don't even "terminate", they just hold 4.2V.
As for your assertion that it is not a bug, did you consider that perhaps the kernel designers are not realizing that there is some kind of parasitic drain on the battery once the kernel thinks it is full?
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Click to collapse
Just out of curiosity what kinda systems do you build? I have a lithium powered moped (lifepo4 48v 40ah) but i wouldn't say i particularly designed or built (just assembled) the battery system, would be good to have some connections with some real battery specialists for later projects.
In any case, the parasitic drain is an interesting idea but its odd that I can go to sleep, and in the morning my unplugged evo hasn't changed even 1% battery life, whereas it drains from 100% to some odd 90+ number happens when its plugged in. So the parasitic drain would have to only happen when its plugged in for whatever reason.
Some interesting stuff from the wiki.
Charging procedure
Stage 1: Apply charging current limit until the voltage limit per cell is reached.[42]
Stage 2: Apply maximum voltage per cell limit until the current declines below 3% of rated charge current.[42][unreliable source?]
Stage 3: Periodically apply a top-off charge about once per 500 hours.[42][unreliable source?]
The charge time is about three to five hours, depending on the charger used. Generally, cell phone batteries can be charged at 1C and laptop-types at 0.8C, where C is the current that would discharge the battery in one hour. Charging is usually stopped when the current goes below 0.03C but it can be left indefinitely depending on desired charging time. Some fast chargers skip stage 2 and claim the battery is ready at 70% charge.[42][unreliable source?] Laptop battery chargers sometimes gamble, and try to charge up to 4.35 V then disconnects the battery. This helps to compensate for the battery's internal resistance and charges up to 100% in short time.
Top-off charging is recommended when voltage goes below 4.05 V/cell.[42][unreliable source?]
Lithium-ion[which?] cells are charged with 4.2 ± 0.05 V/cell, except for military long-life cells where 3.92 V is used for extending battery life. Most protection circuits cut off if either 4.3 V or 90 °C is reached. If the voltage drops below 2.50 V per cell, the battery protection circuit may also render it unchargeable with regular charging equipment. Most battery protection circuits stop at 2.7–3.0 V per cell.[42][unreliable source?]
For safety reasons it is recommended the battery be kept at the manufacturer's stated voltage and current ratings during both charge and discharge cycles.
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I'd have to check, but i am nearly certain this is exactly the kind of threshold charging system that you can use with lenovo's battery maximiser. As the wiki sorta explains, topping it off is fine...If you do it very infrequently (500hrs). Continuous charging from all i've ever learned on any chemistry just continues to corrode the plates until they become worse and worse at holding a charge.
No product manual anywhere will ever tell you to leave your charger plugged in for extended periods of time (save for 8hr battery conditioning on ni-cd, also of which it tells you not to do frequently). Storage instructions for lithium example say to leave the battery at about 70% charge. Extrapolating from that we can see that the lesser of the ideals is being completely empty, or too full.
Just my thoughts, much like everyone else i don't have any actual evidence that this was HTC's intention, just seems weird that they would screw something up that's been pretty much the same on the last 20 phones they made. My guess is they didn't.
Edit: oh, and the reason i bolded the military voltage is because that's another (very similar) idea as to what HTC might have done, which is lower the "full charge" threshold for as i suggested before....longer lifespan. But whether the phone ever actually gets to 100% is kinda irrelevant. My point is that its PROBABLY done intentionally to preserve the lifespan of the battery.

the best battery life and longevity

since owning my evo i have noticed rather peculiar battery life.
one day its ok, the next its gone 5-6 hours.
so i picked up a 3000mah battery for the wife and myself.
same thing. just horrible battey life one day, then the next.. great. i can go all day and charge when i go to bed.
yes i know the 3000mah battery is probably more like 2200-2500mah.
as i think back, and because of my job and some of the solar and battery backup systems we design for microwave radios i started to notice why, aside from heavy usage, i get poor battery life. and why under mid to heavy use i get even worse life.... i am talking 6 hours and i have just about drained a 3000mah battery.
its the HTC charger.....
no it isnt bad.. its charging the battery too quickly.
anyone who knows anything about batteries knows you can absolutely charge a battery too fast and that 9 out of 10 times a slow or trickle charge gives a much better charge on the battery thus giving prolonged use out of your phone.
not all batteries ar the same. some can handle a quick charge, others demand a slow charge.
so..i look back and i can say with total confidence that when i charge with the HTC wall charge my battery life is 1/2 or less what i get if i charge with the usb cable on a pc or with a wall charger that puts out less amps.
i also shut the phone off whenever i can to charge.
the htc charger puts out 5v 1a.
a usb port puts out 5v 500ma, (0.5a) and you can find wall adapters or car chargers that put out the same.
thus the usb port allows for a better cleaner charge.
prolonged use of the htc charger, i truly believe, will greatly shorten the life of your battery. and not just a little either.
so in the end...
1) usb a pc/laptop usb port to charge your phone whenever possible
2) only use the htc charge if you need a quick boost charge.
3) power off your phone if possible when ever using either method.
Sent from my PC36100 using XDA App

This is from a post i made earlier this morning.
i went 3 days 12 hours and 46 minutes on a single charge, that is with using the stock battery and a regular wall charger, yes i'm rooted and i used setcpu to set my frequency to 614 when screen on, and 245 when screen off, at night when i go to sleep i put the phone into airplane mode, and overall usage was cut back to light to moderate usage, i was trying to see how long i could actually go on the stock battery, and i must admit i'm very impressed.
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when i charge this way i leave the phone on, instead of turning it off.

I hadn't given this as much thought as you guys but in retrospect I have to say I've had the same experience. I just never thought the usb charge would be superior to 1a charging, I just thought it was other factors like my usage or signal strength.
Thanks for this thread

Just use Baked Snack if you want battery life, or juice defender/ultimate juice.

tomh1979 said:
This is from a post i made earlier this morning.
when i charge this way i leave the phone on, instead of turning it off.
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LOL, screen shots like that make me laugh.
I mean, its great and all that you are getting that, but dude...its a phone...use it!
Dont use it as a paperweight.

champ052005 said:
LOL, screen shots like that make me laugh.
I mean, its great and all that you are getting that, but dude...its a phone...use it!
Dont use it as a paperweight.
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Click to collapse
the point of it was to see how long it would go period (as in testing), so it was used, just not as much as i normally actually do, read that post again, i think i even said that didn't i not!
Next time please take some time to read the post and think through what it says before posting!

I have had similar issues. For example today my battery has dropped thirty percent in the last hour. I think it's because of poor signal though, atleast for me. I have had my battery die in three hours before because of no signal.
Sent from my PC36100 using XDA App

Signal strength does affect battery life, I have a 700 mah charger from my curve I'll start using that to see I notice any difference in drain. Ill report back in a few days if I remember to.

My time without signal is at around 25% today. My phone has been unplugged for 3.5 hours and is at 28%.
Sent from my PC36100 using XDA App

tomh1979 said:
This is from a post i made earlier this morning.
when i charge this way i leave the phone on, instead of turning it off.
Click to expand...
Click to collapse
Can you point me towards the round clock mod please

tomh1979 said:
This is from a post i made earlier this morning.
when i charge this way i leave the phone on, instead of turning it off.
Click to expand...
Click to collapse
Can you point me towards the round battery mod please

DirtyShroomz said:
Can you point me towards the round battery mod please
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Click to collapse
mine was apart of the Riptide clear theme, so it came with that, however though i have seen a thread in the app and theme section with this, you might want to search in there, i know it's in the first few pages since that is a popular mod.

I just got my wall charger in the mail and am dying to use it. I've read somewhere with the batteries that the EVO uses we shouldn't drain the battery all the way, is this true? If so, that means I can just pop the battery in the charger, yeah? It'd be a pain to have to drain my battery... Thanks for clarification anyone.

CollegeFresh said:
Just use Baked Snack if you want battery life, or juice defender/ultimate juice.
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Click to collapse
this isnt about roms and apps that claim to help battery life. and just to say it, i have yet to have a rom help my battery life.
in fact... my experience is that i get the best battery life on the stock odex roms. not sure why, but i have seen it many times.
i am talking the proper way to charge your phone, and using the wall charger should only be done when you need to give the phone a very quick charge.
i charged mine the other night when it was down to 2% and it took less than an hour and a half to charge the battery, where as using the usb method, would have taken easily twice as long, and provided twice the use.
I will also say that i have owned alot of phones, and this is THE worst battery life i have ever gotten from a phone... period.
HTC isnt known for using long lasting batteries, nor creating phones that are easy on a battery. HTC makes phones with batteries that blow their wad like a teenager getting his first BJ.

v_lestat said:
this isnt about roms and apps that claim to help battery life. and just to say it, i have yet to have a rom help my battery life.
in fact... my experience is that i get the best battery life on the stock odex roms. not sure why, but i have seen it many times.
i am talking the proper way to charge your phone, and using the wall charger should only be done when you need to give the phone a very quick charge.
i charged mine the other night when it was down to 2% and it took less than an hour and a half to charge the battery, where as using the usb method, would have taken easily twice as long, and provided twice the use.
I will also say that i have owned alot of phones, and this is THE worst battery life i have ever gotten from a phone... period.
HTC isnt known for using long lasting batteries, nor creating phones that are easy on a battery. HTC makes phones with batteries that blow their wad like a teenager getting his first BJ.
Click to expand...
Click to collapse
You do know that the Evo can not properly charge an extended battery right? The built in power driver only charges the stock battery correctly. You can check out either of the extended battery threads in the accessories forum for more info. Though charging via usb may give you a better charge, you are still getting cheated out of battery if you charge the battery in the phone.

Systemfraud said:
I just got my wall charger in the mail and am dying to use it. I've read somewhere with the batteries that the EVO uses we shouldn't drain the battery all the way, is this true? If so, that means I can just pop the battery in the charger, yeah? It'd be a pain to have to drain my battery... Thanks for clarification anyone.
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Click to collapse
thats a mixed bag man, there are mixed thoughts on this, personally i follow the mfg. initial instrucitons of 8-12 hours initial charge, regardless if it says the battery is full, then i will do 3-4 complete charges and discharges.
at that point you are good to go to charge anytime you like. alot of places will tell you to not let it go below 20% and thats ok, but be sure to charge it all the way.
The more times you take it off the charger before its full, the greater chance you have of hurting the battery.
all i know is that when i charge it with the wall charger the battery drains very fast. where as with a usb port on a computer... it seems to last alot longer.
what does the evo manual say about how to charge the battery? i personally have never looked.

v_lestat said:
this isnt about roms and apps that claim to help battery life. and just to say it, i have yet to have a rom help my battery life.
in fact... my experience is that i get the best battery life on the stock odex roms. not sure why, but i have seen it many times.
i am talking the proper way to charge your phone, and using the wall charger should only be done when you need to give the phone a very quick charge.
i charged mine the other night when it was down to 2% and it took less than an hour and a half to charge the battery, where as using the usb method, would have taken easily twice as long, and provided twice the use.
I will also say that i have owned alot of phones, and this is THE worst battery life i have ever gotten from a phone... period.
HTC isnt known for using long lasting batteries, nor creating phones that are easy on a battery. HTC makes phones with batteries that blow their wad like a teenager getting his first BJ.
Click to expand...
Click to collapse
Well, the point I was trying to make is that roms and apps are a big part of saving battery. If you want to have a longer lasting battery you should turn off radios when not using them and undervolt as well. Baked snack is an undervolted rom with a good kernel that helps save battery and ultimate juice/juice defender turn off radios for you and have various settings for helping you get a long battery life.
I get 50 hours easily with moderate usage and right now my phone has been on the same battery percentage for 8 hours while playing music for around 1 hour, receiving a couple of texts, 10 min of phone calls, checking internet for 10 min, and having around 1-2 signal bars.
It also helps a lot when you don't use the wall charger, it just plain sucks. When I used it my charge dropped anywhere from 100% to 87-92% in 10 minutes. But with a wall charger from ebay where you put the battery in it, it stays at 100% for a couple of hours so you get an extra 10% and it lasts a lot longer as well.

v_lestat said:
thats a mixed bag man, there are mixed thoughts on this, personally i follow the mfg. initial instrucitons of 8-12 hours initial charge, regardless if it says the battery is full, then i will do 3-4 complete charges and discharges.
at that point you are good to go to charge anytime you like. alot of places will tell you to not let it go below 20% and thats ok, but be sure to charge it all the way.
The more times you take it off the charger before its full, the greater chance you have of hurting the battery.
all i know is that when i charge it with the wall charger the battery drains very fast. where as with a usb port on a computer... it seems to last alot longer.
what does the evo manual say about how to charge the battery? i personally have never looked.
Click to expand...
Click to collapse
I don't mean the wall charger like.. the one HTC gives, I'm talking about the wall charger where you actually put the battery into it.
Sent from my PC36100 using XDA App

MSmith1 said:
You do know that the Evo can not properly charge an extended battery right? The built in power driver only charges the stock battery correctly. You can check out either of the extended battery threads in the accessories forum for more info. Though charging via usb may give you a better charge, you are still getting cheated out of battery if you charge the battery in the phone.
Click to expand...
Click to collapse
i will have to research this but the batteries are the same, only one has more cells.
the only thing the phone does is read the voltage of the battery.
and they are the same whether it is a 1 cell or 3 cell battery.
one just hold more charge.
but i could definitely see where the phone might jack with the charge.

I'm curious if one could split the difference between quick charging and complete charging by charging via the wall charger up to say 80 or 90% then switching to USB for the rest of the charge?

Full charged battery stick at 96%!!!

Hey,
I'm one of the proud nexus s users since a few days. I do have a question. I've got a stock nexus s with 2.3.3 unrooted. When I charge my battery, the phone won't charge more then 96%. I have treid to reboot and charge again, but no succes. Someone has te same or knows a sollution???
Sent from my Nexus S using Tapatalk

As mentioned many times before in this forum, batteries are not meant to be fully charged at all. This is to extend the lifespan of the battery. High voltage (100%) stresses out the battery, so by letting the charge stop at 96% for example, it makes it as full as possible without bringing its voltage to the max. So your battery can last longer and will not need a replacement so fast. Hope this helps.

It's not a problem, its a feature. Ironically, it keeps your battery life longer in the short run and long run.

soylukral said:
Hey,
I'm one of the proud nexus s users since a few days. I do have a question. I've got a stock nexus s with 2.3.3 unrooted. When I charge my battery, the phone won't charge more then 96%. I have treid to reboot and charge again, but no succes. Someone has te same or knows a sollution???
Sent from my Nexus S using Tapatalk
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Click to collapse
if you REALLY want your battery to reach 100% this is what you do. let the phone charge until it stops charging, unplug it from the charger, plug it back in, then continue charging it with the screen on. do not let the screen go off or it will stop charging. this method work, it just takes a lonooong time to reach 100%
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That method is called Bump charge. It's useful to bringing your battery to 100%
But do not do it often because it reduces your battery's lifespan.

I will give it a try. Thanks anyway.
Sent from my Nexus S using Tapatalk

navlem said:
As mentioned many times before in this forum, batteries are not meant to be fully charged at all. This is to extend the lifespan of the battery. High voltage (100%) stresses out the battery, so by letting the charge stop at 96% for example, it makes it as full as possible without bringing its voltage to the max. So your battery can last longer and will not need a replacement so fast. Hope this helps.
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Umm your explanation is why people would see the phone as fully charged at 100% then unplug to find it at a lower percentage. That was because the battery had been fully charged but then stopped charging and had not hit it's bump level. Now however the issue is that some phones seem to just stop charging. Not sure where you got the idea that its bad for them to be fully charged but just think about that statement for a second.
Its bad for them to be OVER CHARGED. Fully charged (4191mV) is great but charging past that point may lead to battery over heating and catching fire as was demonstrated with the trickle charge kernels over on the evo 4g forums. This issue, the one being discussed in the thread is NOT just something people should accept. This is a bug that should be reported to Google.
Sent from my MIUI Nexus S from the XDA Premium app.

kenvan19 said:
Umm your explanation is why people would see the phone as fully charged at 100% then unplug to find it at a lower percentage. That was because the battery had been fully charged but then stopped charging and had not hit it's bump level. Now however the issue is that some phones seem to just stop charging. Not sure where you got the idea that its bad for them to be fully charged but just think about that statement for a second.
Its bad for them to be OVER CHARGED. Fully charged (4191mV) is great but charging past that point may lead to battery over heating and catching fire as was demonstrated with the trickle charge kernels over on the evo 4g forums. This issue, the one being discussed in the thread is NOT just something people should accept. This is a bug that should be reported to Google.
Sent from my MIUI Nexus S from the XDA Premium app.
Click to expand...
Click to collapse
I read it through this page
http://www.androidpolice.com/2010/1...bump-charging-and-inconsistent-battery-drain/
Though it might mention about the problem about "Showing 100% and instant drop after unplug from charger", but I reckon that Google is making Nexus S showing the true accurate charge.

navlem said:
I read it through this page
http://www.androidpolice.com/2010/1...bump-charging-and-inconsistent-battery-drain/
Though it might mention about the problem about "Showing 100% and instant drop after unplug from charger", but I reckon that Google is making Nexus S showing the true accurate charge.
Click to expand...
Click to collapse
You reckon incorrectly.
This is why many new phones will “lose” up to 10% within a few minutes of coming off the charger. The reality is that the battery was only at 100% capacity for a brief moment, after which the battery management system allowed it to slowly dip down to around 90%. Leaving the phone plugged in overnight does not make a difference: the phone only uses the wall current to maintain a partial charge state.
Click to expand...
Click to collapse
I have battery graphs which show the phone is never reaching 100%, or was never reaching 100% (ironically, my phone actually was at 100% for the first time since 2.3.3 this morning). As I said, this is a bug not a feature. Phones should hit 100% then drop to a "bump level" (HTC seems to like 90% whereas I believe Samsung uses 95%) and then charge back up to 100%, as simms said, very slowly. It does this so as to not over-charge the battery because that can lead to severe over-heating issues and can possibly hinder the overall life of the battery. RogerPodacter was able to modify the battery drivers for the N1 so as to prevent this from happening (not quite sure what he modified) but because of the way that Samsung set up the NS battery drivers, this is not possible for us. Again, this is a BUG that should be reported to Google.

Yeah, i might reckon incorrectly. Doing the bump charge now, it seemed to be really slow at charging from 98% onwards though.

I had this issue with galaxy s also with newer firmwares. It is NOT a bug, it's a FEATURE.

JuWa said:
I had this issue with galaxy s also with newer firmwares. It is NOT a bug, it's a FEATURE.
Click to expand...
Click to collapse
LOL The battery not being able to achieve full charge is definitely a feature, ya sure. Absolutely. I can only use 95% of my cars petrol. That's a feature too. Definitely. My paycheck is only ever 95% of what I earned. Its a feature! People think about what you're saying >< a phone not being able to reach its maximum charge is a BUG.

kenvan19 said:
LOL The battery not being able to achieve full charge is definitely a feature, ya sure. Absolutely. I can only use 95% of my cars petrol. That's a feature too. Definitely. My paycheck is only ever 95% of what I earned. Its a feature! People think about what you're saying >< a phone not being able to reach its maximum charge is a BUG.
Click to expand...
Click to collapse
Ehm... Are you stupid or something? What is those things got to dot with the battery CHARGING???

The only real solution is to get a spare OEM battery or two and a wall charger to charge them in. The batteries last 2 to 4 more hours because when I plug one in its fully charged to 100%. Plus I rarely ever have to hook my phone up to a charger anymore. Swapping batteries is so much more convenient.
And I agree this 'feature' to save my $7 battery is not a feature at all. You can find extra batteries and chargers on ebay very easily.

I agree with the above post 100%. Since I got a second (genuine) battery and an external charger, both of my batteries charge to 100% and appear to last longer. Since I started charging them in the external charger, they also now charge to 100% in the phone too. As I said in the other thread similar to this, I'm presuming the battery needed a full cycle and the charging circuitry in the phone just wasn't up to the job.

JuWa said:
Ehm... Are you stupid or something? What is those things got to dot with the battery CHARGING???
Click to expand...
Click to collapse
Wow. Just wow. You don't even vaguely understand irony do you mate?

Oh, Americans... I just love you guys...

Living in America makes me American, does it?

kenvan19 said:
You reckon incorrectly.
I have battery graphs which show the phone is never reaching 100%, or was never reaching 100% (ironically, my phone actually was at 100% for the first time since 2.3.3 this morning). As I said, this is a bug not a feature. Phones should hit 100% then drop to a "bump level" (HTC seems to like 90% whereas I believe Samsung uses 95%) and then charge back up to 100%, as simms said, very slowly. It does this so as to not over-charge the battery because that can lead to severe over-heating issues and can possibly hinder the overall life of the battery. RogerPodacter was able to modify the battery drivers for the N1 so as to prevent this from happening (not quite sure what he modified) but because of the way that Samsung set up the NS battery drivers, this is not possible for us. Again, this is a BUG that should be reported to Google.
Click to expand...
Click to collapse
I've looked to make the same driver changes to the nexus s as I did to the nexus one, but the battery chip model and driver is different so the same changes don't make sense.
I've gone on record saying that this issue with the nexus s not charging to 100% is NOT intentional, its a bug inherent with type of driver used in the nexus s. I just don't own this phone to edit the driver and test.
But there is a line of code which I feel if it was removed, this issue may disappear. I know not everyone agrees. But my nexus one will stay at 100% for an hour and a half, every morning. And my nexus reaches 100% every single day, I've never seen otherwise. So its not the way batteries are supposed to work. If it was, they would just make the top end lower and the 96% mark would be the 100% mark. Just my opinion.

RogerPodacter said:
I've looked to make the same driver changes to the nexus s as I did to the nexus one, but the battery chip model and driver is different so the same changes don't make sense.
I've gone on record saying that this issue with the nexus s not charging to 100% is NOT intentional, its a bug inherent with type of driver used in the nexus s. I just don't own this phone to edit the driver and test.
But there is a line of code which I feel if it was removed, this issue may disappear. I know not everyone agrees. But my nexus one will stay at 100% for an hour and a half, every morning. And my nexus reaches 100% every single day, I've never seen otherwise. So its not the way batteries are supposed to work. If it was, they would just make the top end lower and the 96% mark would be the 100% mark. Just my opinion.
Click to expand...
Click to collapse
my nexus one always reaches 100%, using wildmonks kernels, ravens kernels, and now redstar kernel. if you would like me to try something on my nexus s, edit/delete files. ill gladly help out

[Q] Keeping the Nexus 10 plugged-in

I have read conflicting articles on increasing the battery life of Lithium-ion batteries (the ones used in Nexus 10). Most of the Lithium ion batteries have a lifespan of 300-400 charge/discharge cycles. From my understanding, this means that it is bad to fully discharge the batteries and then recharge them as it reduces from the above mentioned lifespan and it is better to top-off the battery often as possible.
In fact there was an article that I read on Cnet specifically for the iPad (I'm not allowed to post outside links for some reason, google: "ipad keep plugged in" and the first article in the search result) , where they recommend to keep the iPad plugged-in whenever possible to increase the battery life.
I use my Nexus 10 a lot at house. So, Is it better to keep it plugged-in all that time?

roshanpius said:
I have read conflicting articles on increasing the battery life of Lithium-ion batteries (the ones used in Nexus 10). Most of the Lithium ion batteries have a lifespan of 300-400 charge/discharge cycles. From my understanding, this means that it is bad to fully discharge the batteries and then recharge them as it reduces from the above mentioned lifespan and it is better to top-off the battery often as possible.
Click to expand...
Click to collapse
This is correct.
In fact there was an article that I read on Cnet specifically for the iPad (I'm not allowed to post outside links for some reason, google: "ipad keep plugged in" and the first article in the search result) , where they recommend to keep the iPad plugged-in whenever possible to increase the battery life.
Click to expand...
Click to collapse
The life span of LiIon/LiPoly batteries is also reduced when the battery is at or near 100% for a prolonged time. Don't think too much about it, just use the N10 and recharge it often. I usually try to plug it back in around the 70% mark.
It's also quite easy to open up the tablet, you only need a screwdriver and a plastic prying tool and then you can change the battery yourself, if it ever should become necessary (unlikely, unless you plan to use it for ~5 years).
> http://www.powerbookmedic.com/wordpress/2012/11/16/google-nexus-10-take-apart-first-look

i don't care about it... i leave it plugged whenever i can
chances are, those who take "good care" of their battery may end up with 10% more life in 2 years.... and frankly, i couldn't care less about that
not worth the hassle of worrying about batteries anymore

Best practice actually is to drain to 40% and charge up to 80%. Dropping to 90% and charging back up to 100% a bunch is still bad for your battery, as is leaving it plugged in over night when it reached 100% long before you wake up.

EniGmA1987 said:
Best practice actually is to drain to 40% and charge up to 80%. Dropping to 90% and charging back up to 100% a bunch is still bad for your battery, as is leaving it plugged in over night when it reached 100% long before you wake up.
Click to expand...
Click to collapse
It stops charging upon reaching 100%.

Its hard to follow those instructions when your out 24 hours a day, or maybe you just want to use your tablet
Don't worry about doing extra stuff.. like the user said I could careless..
Just don't let your device die, charge it once it hit like 15%..
Saying charge your device once it at 70% is like only driving your car for 5miles and putting it back in the garage and walk the rest of the way..
Sent from my Nexus 10 using Tapatalk 2

YoungAceAtlanta said:
Saying charge your device once it at 70% is like only driving your car for 5miles and putting it back in the garage and walk the rest of the way..
Click to expand...
Click to collapse
I didn't say you have to do that. If it's possible I recharge early, if not I just use it anyway.
Doesn't really matter too much since the battery can be exchanged rather easily if it ever comes to that.

BoneXDA said:
It stops charging upon reaching 100%.
Click to expand...
Click to collapse
Yes, and then it drains a bit and goes back to charging, over and over the rest of the night.

I've read that Li-ion batteries don't like "deep cycles", that is, fully dischanging then fully charging, because this shortens the battery's life. Also that it's not good to have it at 100% for a prolonged time. So it would be best to always have the device partially charged, plugging it if below 50% and unplugging at 90%. When the battery reaches 90% some phones even notify you that "the battery is full, and you can disconnect from charger"
Source: http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

[GUIDE] Prolonging battery life cycle

With my older phone LG P880 I had a fat battery after 2 years of usage and it had very degraded capacity.
Since this phone has an unremoveable battery I did some research to prevent de javu.
So I'll be sharing uncommon tips and tricks to prolong your battery to keep you going for up to 4 years and to preserve it's capacity for longer.
Remember, your battery is like a machine.The more you demand and the more you stress it the shorter it's life will be.
Definitions
Life Cycle --> Amount of charges/discharges your battery will survive through before it's unuseable.
V --> Voltage of your battery.It increases as you charge and decreases as your discharge.This means a charged battery has higher V than a discharged battery.There are lowest and highest thresholds to V that play a key role in prolonging battery life cycle.
Capacity --> 3200 mAH by default for our batteries.Lowers over time due to wear.
Battery Wear --> Batteries wear down over time.A battery that is weared down will have less capacity and less life cycle left compared to a factory new battery.This guide's ambition is to preserve higher capacities for longer and increase life cycle.
V and Percentages
For our phone V/Percentage can be seen below.
-->4.3 V is 100% Charging to this level is like overcharging your battery.Wears the battery down noticeably.ESPECIALLYif you charge your phone over the night, it's a battery killer.
-->3.9 V is 60% Charging to this level is like using your battery the way it was meant to be used.Prolongs battery life noticeably but come on, which one of you can leave the house with 60% juice in your battery? We'll try to avoid this percentage while reducing wear.
-->3.2 V is 15% You should avoid discharging below this level as it will fasten wear.
What max. Percentage should I charge to?
-->4.1 V is 80%-85% and it is said to double battery life cycle as compared to 100%.The 20%-15% tradeoff is totally worth it in long term and it's not as low as 60%.
Sure, you can charge to 100% if you are going on a long trip or you need the extra 20% juice.Thanks to sony we've got great battery life already so for daily usage 80% should do.
-->To make it easy and get notified when phone is charged to 85%, use this freely avaliable app.You can choose the percentage yourself and it even shows voltage values.
https://play.google.com/store/apps/details?id=com.ryosoftware.batterynotifier
Usage :
Open the app up > settings > battery charged settings > tick notify by percent > tap on percent of charge.Remember to launch the app before charging your phone.
Other important factors that effect battery life cycle :
The percentage to start charging at
You don't need to wait for your phone to discharge all the way down to 15%.Infact, recharging your phone and keep it between 40% - 80% where possible increases your battery's life cycle.Because you put less stress on the battery this way which reduces wear.
Temperature
Li ions are known to have problems with difficult environmental conditions.Now there are some li ions with different chemistry which adapt nicely but they are used by military and stuff and not phones because they have tradeoffs.
Temperature can wear down your battery way faster than the cases above.Avoid heat at all times, to do so :
-->Charge your battery at cooler temperatures.Now room temps would do fine (try to not go below 10 C), just find the coolest room you can find and charge it.
-->Never use your phone while it's being charged.When a battery is getting charged and if you use your phone at the same time, you are basically charging and discharging at the same time which wears it down real quick.Also generates heat.
-->Never play demanding games under sunlight/in hot environments.Playing games alone does a good job heating the battery, sunlight added it's like frying your battery.
Calibrating Battery
Image below only for mass effect fans :
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Batteries get inaccurate about percentage and voltage over time.Mostly noticeable after two months of no calibration.However, calibrating once per 3 months should do fine.
-->Discharge your phone to 0% once per 3 months.It recalibrates it.Now you might ask "doesn't that increase wear?" It indeed does but without calibrating your phone at all you might aswell be only using 70-80% of your phone's actual battery capacity.
Sorry for repeating myself but remember, your battery is like a machine.The more you demand and the more you stress it the shorter it's life will be.
Sources : http://en.wikipedia.org/wiki/Lithium-ion_battery and http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
Further proof that this post is not bullsh*t: http://www.xperiablog.net/2016/06/2...soft-charging-landing-this-week-23-5-a-1-238/

Thanks for the guide and the good explanations
I just think it would be interesting to give your sources since there is a lot of false information on this topic.

pec0ra said:
Thanks for the guide and the good explanations
I just think it would be interesting to give your sources since there is a lot of false information on this topic.
Click to expand...
Click to collapse
OP updated with source
EDIT : OP updated with detailed info, few tricks added

Nice.
Now if we just had two Z2 one charged from 0-100 and another from 20-80 for over 2 years, then we could see the difference.
If we just had something like THIS not from 2010 but 2015 with 3200mAh Battery from Sony.

I believe in stressing the battery by charging it fully to 100%. I always charge at night until morning. The sweet spot for is 90. Sony created Li-ion batteries if I'm not mistaken and they know a lot about batteries. That's the reason why Sony phone's light indicator turns green when 90% charged already.
Sent from my D6503 using XDA Free mobile app

thanks that was some really useful information

Haldi4803 said:
Nice.
Now if we just had two Z2 one charged from 0-100 and another from 20-80 for over 2 years, then we could see the difference.
If we just had something like THIS not from 2010 but 2015 with 3200mAh Battery from Sony.
Click to expand...
Click to collapse
No offense but you're just being a sony fanboy here.Battery tech is the slowliest proceeding tech out of every other components' and battery quality is averagely the same with the exception of some very low level products.Even so, in the article over there in battery university it says that those 1500 mAh batteries were made for smartphones and brand new.
Cropped from sony xperia z2 'environmental' (can be found on sony website) :
Quote from Wiki :
(LiPo = Lithium ion polymer)
Safety
LiPo cells are affected by the same problems as other lithium-ion cells. This means that overcharge, over-discharge, over-temperature, short circuit, crush and nail penetration may all result in a catastrophic failure, including the pouch rupturing, the electrolyte leaking, and fire.[21]
All Li-ion cells expand at high levels of state of charge (SOC) or over-charge, due to slight vaporisation of the electrolyte. This may result in delamination, and thus bad contact of the internal layers of the cell, which in turn brings diminished reliability and overall cycle life of the cell.[12] This is very noticeable for LiPos, which can visibly inflate due to lack of a hard case to contain their expansion...
Click to expand...
Click to collapse
P.S: Feel free to proceed with buying two xperia Z2's and charging them differently though, you may discover something new that every sciencist on the world couldn't.

ottomanhero said:
.Even so, in the article over there in battery university it says that those 1500 mAh batteries were made for smartphones and brand new.
P.S: Feel free to proceed with buying two xperia Z2's and charging them differently though, you may discover something new that every sciencist on the world couldn't.
Click to expand...
Click to collapse
I've had one of those 1500mAh Batteries in my X10
Compared to the Z2 battery the capacity has increased by 2.1 while I doubt that the volume has increased by 2.1x!
I believe that this "good usage" will increase battery life. Yet I'd love to know by how much exactly. 10%? 15% 20%?
Just "better" doesn't satisfy me
Sadly the cost for good testing equipment easily overwhelms the cost of 2 Xperia Z2 ^^
BTW, according to Kernel Adiutor:
5% is 3.6V
1% is 3.4V
You might want to check that.
Edit:
Here we also have the Voltage when fully charged.
While plugged 4.3V
After unplugging, more like 4.2V

Yes, 4.2 V is the safe highest voltage for use, however charging till 4.1 V is lot better for prolonging battery life.Also like you said, 4.3 V when charged but still plugged in.Which is why you should avoid charging over night.
Voltage status may differ between apps, for example cpu-z shows around 3.4 mV for me when it's 10%

isn't it the other way around?
Android system gives a Voltage value read from the battery and is calculating the % Battery remaining from this?
So they % You have is depending on the ROM you're using but the Voltage reading of the battery will always be the same?

Android system reads both the voltage and percentage seperately.This is one of the reasons why battery calibrations is required at times.If you haven't calibrated your battery for half a year or so, it may show 100% at 4.0 V or something lower compared to 100% at 4.2 V ~ which would give you less of your battery.
Voltage reading is not exact mostly, rather approximate.But yes, it is more reliable than percentage and shouldn't differ between ROMs.

Thanks for this guide, I have just one question. Is it matters that in how many parts I charge it? For example I charge it from 40% to 80% in one part (I start charging and let it charge until it reach 80%) or charge it in more parts (like I charge it for half an hour and then play ten minutes and then again).

maddboss said:
Thanks for this guide, I have just one question. Is it matters that in how many parts I charge it? For example I charge it from 40% to 80% in one part (I start charging and let it charge until it reach 80%) or charge it in more parts (like I charge it for half an hour and then play ten minutes and then again).
Click to expand...
Click to collapse
Older tech batteries had a famous knowledge : "plug once in and charge till 100% without interruption or else battery dies fast"
However, li-ion batteries have no problem with how many times you plug it into charge.
For example you can plug-unplug your charger thrice to charge from 40% to 80%, but then you can also plug it in and charge from 40% to 80% without any interruptions, it will wear the battery just the same.
Only things that matter is that you must not discharge below 3.3 V and try to avoid above 4.1 V, maintain room temperatures while charging and do not use the phone while charging.

Oh.... and i've made some nice graphs
THIS
is the reason why you shouldn't use your phone till it's death.
Under 10% the Voltage drops below 3.6V which is unhealthy.

From what I see new batteries can handle 4.35v unlike older 4.2v models
Charging
Main article: Lithium-ion battery § Charge and discharge
Just as with other kinds of lithium-ion cells, the voltage of a LiPo cell depends on its chemistry and varies from about 2.7-3.0 V (discharged) to about 4.20-4.35 V (fully charged), for cells based on lithium-metal-oxides (such as LiCoO2), and around 1.8-2.0 V (discharged) to 3.6-3.8 V (charged) for those based on lithium-iron-phosphate (LiFePO4).
The exact voltage ratings should be specified in product data sheets, with the understanding that the cells should be protected by an electronic circuit that won't allow them to overcharge nor over-discharge under use.
Click to expand...
Click to collapse
https://en.wikipedia.org/wiki/Lithium_polymer_battery
& something direct from sony
http://talk.sonymobile.com/t5/FAQ/Battery-time-and-enhancement-features/m-p/347874#U347874
Sent from my D6503 using XDA Free mobile app

THANK YOU VERY MUCH FOR YOUR HUGE EFFORTS!
If I Helped, Leave A Thanks ?

Why do you use mV to indicate the voltage?
The battery goes from ~3.2 volts to ~4,2 volts, not ~3,2 milivolts to ~4,2 milivolts ?
(I use ~ to indicate "approximately")
Other than that, you're quite right that it is preferred to maintain a maximum battery capacity over time to prevent total charge and total discharge.
But on the other hand, the last bit of charging is a lot slower as the battery is charged more carefully so the impact is not that big.
If you use the phone, and not let it charged 100% while the phone is turned off for a longer period, it isn't that bad. Maintaining a high voltage for a long time is bad but as we all use the phone permanently, the time it remains fully charged is quite short.
And we talk about a few percent worse after 1000 full charge cycles. Imagine one full cycle a day (from 0% to 100%) that is a few percent less capacity in three years. Personally I did not have a smartphone for over three years yet and I prefer taking profit of not having to recharge than knowing that I will have a few percent worse capacity when my phone is "old and slow" anyways in 2019.
Don't take my remark as a flame, I'm just giving my opinion

For me this guide can't be followed in the real life because it would be very stressful and I change my phone every year and a half so I shouldn't be worried about my battery life (especially SONY devices)
However, I can't deny that you done a great job writing this thread
WELL DONE :thumbup:
If I Helped, Leave A Thanks ?

Just an update on the topic, Sony has confirmed they will add "soft charge" which is basically the same thing as following this guide but automated.It is also gonna be in beta versions pretty soon as far as I've heard http://www.xperiablog.net/2016/06/2...soft-charging-landing-this-week-23-5-a-1-238/
Haldi4803 said:
Nice.
If we just had something like THIS not from 2010 but 2015 with 3200mAh Battery from Sony.
Click to expand...
Click to collapse
pec0ra said:
Thanks for the guide and the good explanations
I just think it would be interesting to give your sources since there is a lot of false information on this topic.
Click to expand...
Click to collapse
*cough* guys, sony wouldn't add such feature if it did not infact prolong battery life.

I have a Xperia Z2 D6502 2 years old.
My back cover had become curved due to swollen battery. I ordered a new duplicate battery from here
http://www.amazon.in/Battery-Xperia-D6502-3200mAh-Generic/dp/B01H5HJ79K?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00
When I opened my back cover for replacing the battery, I realized that battery case had not swollen but there was Air trapped in the thin plastic covering of the battery.
I can easily feel the air. Its like the air trapped in a thin plastic bag.
My new duplicate battery gives me 3.5 hours of screen-on time while my old swollen battery still gives me 5 hours of screen-on time.
Can I remove the air by pricking a safety pin and continue to use the old battery?