Fast Charging cable overnight ok?

[dlgus]

best bet is to shut. phone off at night

ROTFLMAO

 

[LeoRex]

That sounds like the old school charging advice I used to hear back in the old days.
Personally, in an era where phones cost an arm and a leg, and there is no option to remove/replace batteries, I find it hard to believe that Samsung would deliberately design a phone where the battery life would be significantly diminished by charging.

Well, Samsung bucks the trend here a bit. Many OEMs, in an effort to get the highest energy density possible, are sourcing batteries that charge to 4.4v.... this is really the upper limit where it is safe for the battery chemistry.... and increases the amount of stress the cell is under at those higher charges.... Not that they are significantly lower, they go to 4.35V, but that 0.05V difference does lead to less stress... but some don't think that is due to longevity, but the face that they have tighter tolerances in their phones to allow for swelling over time (phones often allow for as much as a 10% increase in battery pack size) to shrink their phones a bit.

It was only a generation or two ago that those cells were charged to around 4.22v... that's why you'll hear people say "I have a phone from 5 years ago that is still holding a pretty good charge but the one I got last year is toast." Yep...

 

[LeePeyton]

This post caused me to fall down a rabbit hole of looking Galaxy S7 components, so I created an account. With the S7/S7edge the main PCB board and power PCB board are seperate. The micro-USB does many things looking at how the ribbion cables are routed, one of those things is power to the main board before it hits the battery. An interesting component is the Fairchild FPF2495B Load Switch that's slew rate controlled with adjustable current-limit control. This sets it back to the laptop analogy. So charging your phone, the load switch should know to direct power with a fail over back to the battery when it's no longer getting direct power, just like a laptop. So I would think with it load switching with different power paths they planned ahead since we don't get to switch out batteries. If I am misunderstanding the way this load switch works, I welcome any input.

 

[chanchan05]

That sounds like the old school charging advice I used to hear back in the old days.
Personally, in an era where phones cost an arm and a leg, and there is no option to remove/replace batteries, I find it hard to believe that Samsung would deliberately design a phone where the battery life would be significantly diminished by charging.
OTOH, I would not have believed the N7 debacle, had it not happened to me...

It's not deliberate design. It's simply how the lithium ion battery technology works. Samsung actually is researching to get around this. They claim that after around a year of use (approx 300-500 cycles), the lithium ion batteries on the S7 Edge retain 85% of their capacity, while older versions of lithium ion batteries only retain 75% or lower. The new tech on the S8 claims it retains 90% capacity.

Anyway the gist is, basically, batteries work by ion movement, and like a machine, these ions wear out over time due to use. And similar to machines, heavy use wears them out more. You're more likely to break an engine by running it for 1 day at max rev, than running it over a month at half capacity. The smaller the depth of discharge, the lower the wear. Lab tests have concluded that when you constantly discharge from 100 to 0, it allows you betwrrn 300-500 charge cycles before it starts to break down and not hold charges. More specifically, when you reach that magic number your battery can only hold a fraction of it's original charge (the S7 is said to hold 85%). That's typically 1-2 years of use if you charge once a day. And heavy abusers charge more than once a day, so that decreases the time span to however many weeks it takes them to reach 500 charge cycles. Now, the increase in charge cycles is exponential, not arithmetical. So a depth of discharge to 50 before recharging will not give you 600-1000 charges. Rather it will give you 1200-1500 charge cycles. Mathematically, draining a 3600mah to zero for 300 charges gives you 1080000mah to burn through however short your battery life will be. On the other hand, using only 50% of the battery before recharging gives you 2160000mah to burn through before it expires after at least 1200 charge cycles. In other words, it stored twice more power for you to use. If you say, charge once every 24hrs, going always from 100 to 0 gives you at least 300 days. Recharging twice a day at 50% gives your battery at least 600 days of use before battery capacity deteriorates. Discharging to 75% before recharging actually gives you 2000-2500 charge cycles, making it even longer. Basically the point is, always plug the phone in when given the chance. Don't wait for 50%, or whatever. 40% is an arbitrary number actually, not sure why it's chosen. Also, this is why one of the choices to auto activate power saving in the S7 is at 50%, so that it keeps the battery up as close to 50% as possible when you get the chance to plug in.
*
As for charging to 80%, this is because partial charge is better than full charge for lithium ion batteries. The ions are placed on stress to hold charges. Maximum stress is at 100% charge. And like everything else, stuff tends to break more with additional stress. So not running it to 100% all the time will reduce overall stress experienced and increase the time before deterioration occurs. Personally I charge to 90%, and discharge to 40% or above. That's a 50% depth of charge, so that's good for up to 1200-1500 charge cycles, plus whatever number of cycles the decrease in max stress gives me.

However, note that environmental temperatures also play a role in battery longevity.

 

[ticketbabe2]

I've read so many different opinions that I don't know what to believe when it comes to the effects of fast charging and leaving it to charge overnight but I do know that my S6 battery (which was never great to begin with) became utterly terrible after about 16 months. I always used fast charging and regularly kept it plugged in overnight.

So for my S7e, I will only use fast charging when needed and avoid leaving it plugged in after it reaches 100%.

I've stopped overnight charging simply for safety on my nightstand. This phone charges so fast on the fast-charger that by the time I brush my teeth & wash my face, it's fully charged.

 

[anon(5719825)]

I sometimes leave one of my S7 Edge phones on the charger for a day or two and there has never been any damage. I've also done the same thing with my one month old S8 and my 1.5 year old Note 5.

Simply put, don't worry about the battery on the wireless charger or while plugged in. No damage will happen.

Just use your phone and charge it however you want to charge it and you will not ruin the battery.