Battery myths. It is OK to leave your phone plugged in over night.

[Tabish Syed]

I posted this as a reply to a certain someone spreading false information but I see many people have this misconception that it is bad to leave your phone plugged in because it will "overcharge" or "explode" or "catch on fire" or something..... Some say "oh but battery widget reads 4.2v or 4.3v that is bad...." Here are the FACTS:

1) New battery chemistry in modern phones is not 3.7 nominal volts and 4.2 volts charged. Instead it is 3.85v nominal and 4.35v charged. (For example in my galaxy note 4)

2) Google CC/CV charge curves. When the battery is low, initial phase is high current but the curve changes once the battery hits a certain voltage and the charging current gradually drops until it hits 0 at full charge.

3) Protection circuits monitor voltage, charge and discharge currents as well as battery temperature. Leaving your phone plugged in will not let the current or voltage exceed rated specs due to charging / protection circuitry in the phone and battery.

4) Always keeping your battery below 100% (like say 90) will have negligible effects on increasing battery lifespan (and by then you will have replaced your phone long ago).

So basically it is perfectly fine to leave your phone plugged in to the charger like you do with a laptop.


Source: Research, experience with Hobby grade Li-Ion and Li-Po batteries/chargers.

Galaxy nexus, Galaxy Note 2, Galaxy Note 4 all left overnight with zero issues and no noticible battery degradation.

 

[calebleesdad]

I'm not going to dispute the points you've posted and really appreciate the time you've spent to help others, but the one time I did leave my note 4 connected to the fast charger overnight I got a notification to disconnect the phone...something to the effect of "battery at 100% disconnect from charger". I have not seen this when connected to my laptop or desktop. I don't think my phone will explode but isn't this some warning from Samsung related to their batteries, perhaps?

Since then I prefer to charge my phone in the morning as I get ready to leave. It charges up full quickly and doesn't stay on the fast charger past an hour at most.

Posted via the Android Central App

 

[D Android]

I'm not going to dispute the points you've posted and really appreciate the time you've spent to help others, but the one time I did leave my note 4 connected to the fast charger overnight I got a notification to disconnect the phone...something to the effect of "battery at 100% disconnect from charger". I have not seen this when connected to my laptop or desktop. I don't think my phone will explode but isn't this some warning from Samsung related to their batteries, perhaps?

Since then I prefer to charge my phone in the morning as I get ready to leave. It charges up full quickly and doesn't stay on the fast charger past an hour at most.

Posted via the Android Central App

I agree with that. There must be a reason why the phone tells you to disconnect the charger when battery is fully charged and you will get the same message even when connected to the laptop, just takes longer to get to 100%.

 

[clevin]

Jesus, you have no clue what you are talking about and blatantly misleading people here.

You completely ignore the laboratory test results with real, precise measurements, and based your false statement on your own " Research, experience with Hobby grade Li-Ion and Li-Po batteries/chargers. "? Jee, with your method, who need science?

 

[Kamau]

I'm not going to dispute the points you've posted and really appreciate the time you've spent to help others, but the one time I did leave my note 4 connected to the fast charger overnight I got a notification to disconnect the phone...something to the effect of "battery at 100% disconnect from charger". I have not seen this when connected to my laptop or desktop. I don't think my phone will explode but isn't this some warning from Samsung related to their batteries, perhaps?

Since then I prefer to charge my phone in the morning as I get ready to leave. It charges up full quickly and doesn't stay on the fast charger past an hour at most.

Posted via the Android Central App

Probably more of a reminder than a warning. I've seen it on other phones when it's reached 100 percent.

 

[ab304945]

I have left my s5 on the charger over night, every night since July. And have no battery issues.

The same with my s3 i had for 2 years with no problems

Posted via the Android Central App

 

[Mojofilter9]

The phone comes with a removable battery, why would anyone care about something that *may* marginally decrease performance over an extended period of time??

Charge your phone overnight because that's clearly the most convenient was of doing it, worst case scenario is that you have to spend £15 in 12 months time.


Sent from my iPad using Tapatalk HD

 

[worwig]

Also, the battery is removable. That means that the battery pack also has protection in it from overcharging, under discharging, and over current. Plus of course the phone has those protections. It is double protected from damage. Leave it plugged in all night. Wake up to 100%. Win.
The unplug message is just a reminder. If it was doing something important, it would be automated. LiIon and LiPo battery charging can't be left to 'I hope you see this message'.
If you unplug it, the phone will operate from the battery. That will be cycling the battery. That WILL use battery life.
I have a Surface tablet that reports battery wear. It is over two years old, and spends 90% of the time plugged into power and at 100%. The lithium battery pack is showing about 3% wear after over 2 years at 100% on charge. No issue there.

But in the end, we buy these portable devices to meet OUR schedules. And in particular the Note has a replaceable battery. Do what works for you. Putting mine on a charger whenever I'm not using it works for me.

Go to THIS well written article:
Smartphone Futurology: The science behind your next phone's battery | Android Central

Glance over the boring details if you wish and go straight to THIS: Tips for improving lithium battery longevity

 

[hamsterwheel]

I have always done this every night for any phone I have ever had with no issues at all.

Granted with the Note 4, I use my BlackBerry charger which is not the "fast charging" one, but no issues with battery life at all.

 

[jwt873]

I've charged all the cell phones I've ever owned overnight for the last 15 years without any problems.

Out of interest..... On page 186 of the Galaxy Note 4 (English) User's Manual it states:

Avoid charging your device for more than a week, as overcharging may shorten battery life.

So If leaving the phone on charge for seven days (168 hours) MAY shorten battery life... I think it's pretty safe to say taht leaving the phone on charge for 12-14 hours overnight won't really do any damage.

Actually everything there is to know about changing is in the manual. Pages 16-18

 

[scassel]

Same as others...have charged over nite for years with no I'll effect. My take on the "warning" has been to remove the brick from the wall outlet more than remove the phone to spare the battery from "over" charging. It's the green thing to do.

Posted via the Android Central App

 

[Tabish Syed]

Jesus, you have no clue what you are talking about and blatantly misleading people here.

You completely ignore the laboratory test results with real, precise measurements, and based your false statement on your own " Research, experience with Hobby grade Li-Ion and Li-Po batteries/chargers. "? Jee, with your method, who need science?

You present zero facts. Let's see this science you speak off.

 

[Tabish Syed]

I'm not going to dispute the points you've posted and really appreciate the time you've spent to help others, but the one time I did leave my note 4 connected to the fast charger overnight I got a notification to disconnect the phone...something to the effect of "battery at 100% disconnect from charger". I have not seen this when connected to my laptop or desktop. I don't think my phone will explode but isn't this some warning from Samsung related to their batteries, perhaps?

Since then I prefer to charge my phone in the morning as I get ready to leave. It charges up full quickly and doesn't stay on the fast charger past an hour at most.

Posted via the Android Central App

Its just a reminder that the battery is done charging.

 

[pappcam]

I have used my phone as my night clock/alarm clock since the days of the BlackBerry Curve all the way through my S3 and Note 4 and I've never "damaged" or ruined my battery in any way.

I'm also tired of misinformation being spread as fact on message boards but hey, it's your phone to do with what you want. If you want to take advice from anonymous people on the internet with absolutely no real world basis for their information, have at 'er.

 

[AndroidHabit]

I have always noticed and so have others, that when you leave your phone charging overnight, it lasts longer.
Once the battery notification pops up and says to remove the charger, it is meant to save household energy.
The phone will stop charging the battery through the night and only trickle charge if it falls below 100%.

 

[Tabish Syed]

Same as others...have charged over nite for years with no I'll effect. My take on the "warning" has been to remove the brick from the wall outlet more than remove the phone to spare the battery from "over" charging. It's the green thing to do.

Posted via the Android Central App

You missed the point entirely ! It cannot overcharge. There is a cutoff once it hits a certain threshold (about 4.35v). The warning is not a warning. It's just a reminder that it is done charging.

 

[jwt873]

But there is a warning about overcharging in Samsung's Note 4 user manual... (See post #10 above)

On page 186, it says "Avoid charging your device for more than a week, as overcharging may shorten battery life".

 

[carlos12001]

I've always kept mine plugged in overnight. Always will.

Sent from my glorious note 4.

 

[plumcrazy]

But there is a warning about overcharging in Samsung's Note 4 user manual... (See post #10 above)

On page 186, it says "Avoid charging your device for more than a week, as overcharging may shorten battery life".

more than a week and "MAY" are very different than overnite and definitely will cause an issue

 

[worwig]

But there is a warning about overcharging in Samsung's Note 4 user manual... (See post #10 above)
On page 186, it says "Avoid charging your device for more than a week, as overcharging may shorten battery life".

Yep.
It is a 'catch 22'. IF you leave it at 100% on charge for a LONG time, it will wear the battery a bit over a long time. IF you leave it closer to 50% it will last longer. BUT, when using the battery, you are wearing it out. In other words, if it is unplugged and near 50% you are wearing it out. So the only way to get long battery life is to pull it from the phone at 50% and store it. Impractical.
In other words, if you are using the battery AT ALL, it is wearing it. If you plug it in and leave it for weeks, you are wearing it out. So use it how it fits your schedule. (Do avoid heat, that is a real killer, and it is practical to control that)
But the point of this thread is valid. A lot of people think that an overnight charge is a horrible thing. It really is not, and in fact might be the best thing to do to get longer battery life.

From my personal view. My wife often forgets to plug in her phone at night. She is often plugging in the phone only after it gives a low battery indication. I have always plugged mine in if I am near a charger and left it overnight. Her batteries appear to show a lot of wear after a couple of years and her battery life is poor. Mine after a couple of years are performing about as well as new.
Of course it may also be that she yacks on the phone a lot more than I do.