Charging the battery

[Don Valdini]

I charge my phone (Samsung Galaxy S8) once a day and it's when I go to sleep and the battery is at 10-20 percent and I leave it charging overnight. But recently I've been reading that to extend the battery life, the batteries must be charged when they're at 40-80% or 50-95%. Is this really true? Because this implies that I have to charge my phone twice or maybe thrice a day (and that's bad, right?), or I would have to pretty much not use the phone during a whole day the way I like to. So what should I do?

 

[B. Diddy]

Welcome to Android Central! This is always the subject of some debate on these forums, but if you search the web, almost every battery expert will recommend a goal of 40-80% for lithium battery in order to prolong its overall lifespan. From a practical standpoint, this can be challenging for a smartphone -- there are apps that can regulate when the phone stops charging, but realistically, the kind of degradation you might see from charging to 100% on a regular basis won't be noticeable for the period of time most people own a particular phone. I think it's a good idea to start charging at around 30-40% as a rule of thumb, but occasional drops to lower levels aren't going to suddenly kill the battery. It's all about your habits. If you let the battery drop to zero every single time, the lifespan will decrease significantly, and you may notice the battery not holding charge as well in as little as 6-12 months.

BatteryUniversity.com, which is run by Cadex, is a great resource to learn more.

 

[Don Valdini]

Hi, yeah I don't let it drop to 0%, and what I really want to know is which one of the methods kills the battery faster : charge it once a day from 15-30% to almost 100% or charge twice or thrice in a day from 40% to 80%

 

[B. Diddy]

I'm not a battery expert, but for the expected average duration of ownership (i.e., 1-2 years), I'd say there won't be a noticeable difference.

 

[Mooncatt]

This is one of the most comprehensive articles on how different charging and storage practices can affect overall battery health.

https://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries

Long story short, Li-ion batteries prefer a happy medium. You'll often hear they have no memory effect like older Ni-Cad batteries, which is true to a point. Two half, charge cycles count the same as one full cycle. When you start looking at other variables that come into play, you'll find that isn't always the case. For example, if the battery is hot, charging puts a lot of stress on it. Charging from 0-100% puts an extreme amount of stress on it. So if you're in a situation like that (like working at a construction site in summer), you'll be far better off charging a little here and there vs all at once.

 

[mustang7757]

I charge my phone (Samsung Galaxy S8) once a day and it's when I go to sleep and the battery is at 10-20 percent and I leave it charging overnight. But recently I've been reading that to extend the battery life, the batteries must be charged when they're at 40-80% or 50-95%. Is this really true? Because this implies that I have to charge my phone twice or maybe thrice a day (and that's bad, right?), or I would have to pretty much not use the phone during a whole day the way I like to. So what should I do?

Hi, welcome!
I usually charge my phone the same at 10 to 20 percent range and don't think much about it . You should get at least 2 to 4 years out of the battery , just avoid extreme temperatures and letting the phone die often .

 

[Rukbat]

Charging from 40-95 won't harm it - it's just that if the charger chip fails, and the battery keeps charging when it's at 100%, you can overheat it and damage it, so cut it off somewhere below 100%. (Even if you disconnect the charger just when it reaches 100%, you'll see it drop to 99% almost immediately - the phone is measuring the charger's voltage until you unplug it.)

To make it easier, if the phone is rooted, there are apps that can actually limit the charge, so you just leave it plugged in and it starts charging at 40% and stops at whatever you have it set for, even if it's plugged in all day. Or at least install GSam Battery Monitor and set the alarms for where you want them, so you won't pick the phone up to go home and find an almost dead battery - or have to check the phone every 5 minutes when it's charging. (It can shock someone to hear your phone playing a loud "Dueling Banjos" [which is the alarm I use] but then I know to disconnect the charger.)

 

[mustang7757]

Charging from 40-95 won't harm it - it's just that if the charger chip fails, and the battery keeps charging when it's at 100%, you can overheat it and damage it, so cut it off somewhere below 100%. (Even if you disconnect the charger just when it reaches 100%, you'll see it drop to 99% almost immediately - the phone is measuring the charger's voltage until you unplug it.)

To make it easier, if the phone is rooted, there are apps that can actually limit the charge, so you just leave it plugged in and it starts charging at 40% and stops at whatever you have it set for, even if it's plugged in all day. Or at least install GSam Battery Monitor and set the alarms for where you want them, so you won't pick the phone up to go home and find an almost dead battery - or have to check the phone every 5 minutes when it's charging. (It can shock someone to hear your phone playing a loud "Dueling Banjos" [which is the alarm I use] but then I know to disconnect the charger.)

I'm curious because I never did your method and probably couldn't, how long your battery has lasted 4 to 5 years? and how long you been doing this technique?

 

[Rukbat]

Years and years, since I worked at developing batteries. But with cellphones, since about 2011, with an old Samsung Precedent. Both batteries are still about 90% good, because I bought a Note 3 in 2013, and just kept the Precedent's batteries around 50% since then. But the Note 3? I've replaced the battery once (that's just over 6 years now). And I had to use it this morning, because I bricked my Pixel 2 updating it again, and had to make a check deposit, so I needed a phone that worked. (Then spent 2 hours getting the thing to recognize the PC again, so I could flash the boot.img file, so I could install the November ROM [which is fun, if you keep checking Google | Factory Images for Nexus and Pixel Devices - then seem to be losing their CSS file since adding the November ROMs and upddates, and keep reverting back to the pages with the October ROMs and updates, evidently trying a fix, then putting the new pages back - only to still have something wrong. (It's fun watching someone else messing up a site for a change.)])

But the Note 3 battery is about 2 years old and still close to 100%.

 

[Don Valdini]

Ok, charging from 40-95 won't harm it, so can I do that like twice or thrice a day?? What I'm trying to know is how many times I can charge it during one day without doing any damage