Is it bad to charge a battery to 100%?

[elel]

In YouTube videos, it is said that charging a smartphone battery to 100% can shorten its lifespan. Is this true? I have always charged all batteries to 100%, whether it is a phone, laptop, camera, or drill battery. Does this rule also apply to drill batteries? When charging batteries, you can only see the charging level in smartphones, but when charging a camera or drill, it is not known when it is at 90% or 95% charge. When using a laptop at home as a desktop computer, if it is plugged into an outlet, the battery is always charged to 100%, and if you disconnect the laptop from the outlet every now and then at 95% battery charge, the battery supposedly wears out quickly because it is frequently charged and discharged. Is there any application for Windows 10 and Android smartphones that sets an alarm when the battery is charged to 95%? Does charging an electric bike or electric car to full capacity also wear out the battery faster? Batteries deteriorate quickly in the sun, so if someone had an electric bike or car, would they have to keep moving the vehicle towards the shifting shade when parked under a tree?

It is also said to let the phone battery discharge completely to zero once a month because electrons in the battery need to move around from time to time, and it is not good for them to be in the same place all the time. Therefore, if you let the phone completely discharge, the electrons will rearrange themselves in the battery again. Is this true? Is it true that once the battery is charged to 100%, every minute and hour of charging wears out the battery and shortens its lifespan?

Is it true that when a smartphone battery is being charged, the electronics disconnect the power supply to the battery once it reaches 100%? I have some batteries that don't fit any device, but I keep them just in case and once every six months, I charge them directly from the charger through a clip that I attach directly to the battery. Can such charging permanently damage the batteries, or is it better to keep them completely discharged when there is no possibility of charging them through any device, and when the only charging option is directly through the charger?

 

[serpretetsky]

BU-415: How to Charge and When to Charge? - Battery University

Edit:
Also, depending on the battery and what you are trying to achieve full discharge and recharge maybe something you want to do (refer to the link, this depends on the chemistry and what's wrong with the battery), however it is not because "electrons in the battery need to move around from time to time ". It's either because you need certain chemical reactions to occur in the battery, or because you are "recalibrating" the electronics inside the battery (in the case of managed/circuit protected li ion batteries)

 

[Fanatical Meat]

I’ve heard a simple rule is keep lithium batteries around 80% charged and keep them from hot or cold to have maximum battery life as in maximum amount of time before battery fails.

 

[CropDuster]

My S20+ has a setting to only charge the battery to 85% to prolong its life. I assume it works as intended

 

[mindless1]

Don't buy devices where you can't afford to replace the battery, then you won't become a slave to these worries. Remember, things you use, are going to need a new battery anyway. Recycle the old battery, materials to make them are not infinite and instead are in short supply, can't meet demand.

Phones might be an exception, in that some people break/lose/upgrade before their original battery is too weak to last between reasonable recharge opportunities, and most phones now require microsurgery to replace the battery.

I suppose there are more and more exceptions appearing in the market as more and more devices come with built-in lithium rechargeable batteries. That is up to you, whether to purchase something with an end of life due to battery lifespan and frequency of use, or whether you can source and solder in a new battery when the time comes.

Just about every battery form factor in products, is also available in the aftermarket to replace the individual cells or packs, if you know where to look, except proprietary cartridge batteries where the cartridge can't be non-destructively opened. Older phones and some cameras come to mind as the most common place to find those.

Take youtube videos with a grain of salt.

 

[shortylickens]

Those videos are made by ignorant people trying to sound cool. Stop watching them.
Modern phones dont actually charge up to 100 percent. They know people freak out about numbers and pretty much all of them lie to you nowadays. When your phone says its at 100 percent, its not.
That was easier than trying for the last 30 years to repeatedly explain how batteries work.

 

[Trader05]

All the phones I ever had, I charged at night to 100% to the morning. My previous iPhone 11 Pro had battery health of 97% after two years and my Pixel 6 Pro is at about 96% after 18 months - both adaptive charging off.
Just use it and charge it with a name brand charger and cable you'll be fine.

 

[skriefal]

Charging to 100% is fine. Just don't leave the phone connected to the charger and at 100% charge level for most of its life. Most of us wouldn't do that - but there are rare occasions where that is done. And that's why Samsung has the 85% charge limit buried in the settings.

Charge your phone to 100% when it needs to be charged. Then unplug or remove it from the charger. Don't worry if it sits a few hours at 100% until you wake up. Charge it again - if possible - before the battery drops below 20%. That's really all that needs to be done.

 

[dlerious]

A PC Mag article on smartphone batteries.

Charging Your Phone Overnight: Battery Myths Debunked

Is it bad—or even dangerous—to leave a smartphone plugged in as you sleep? The answer is complicated, as are many things regarding batteries.

www.pcmag.com

 

[tcsenter]

Charging to 100% is fine. Just don't leave the phone connected to the charger and at 100% charge level for most of its life. Most of us wouldn't do that - but there are rare occasions where that is done. And that's why Samsung has the 85% charge limit buried in the settings.

IPhone does as well. Called 'Optimized Battery Charging' under Battery Health, so that it will try to reduce the amount of time the battery is connected to the charger beyond reaching 100% charged state. If you do not often leave the device connected to the charger for long after reaching full charge, then this is not required.

My question is, why don't the companies build in the feature to STOP charging once the battery reaches full charge?

 

[lxskllr]

I charge mine to 65%, don't let it drop below 20%, and 99%+ of the time, I slow charge using a usb port rather than fast charge. Works for me, but I wish it were all automated, and I'd prefer charging even slower.

 

[Red Squirrel]

In general lithium ion batteries don't like to sit at 100%, so I sometimes let mine charge that far but because it's on it's basically draining right away. I typically try to stop the charge at like 80-90% though. I also avoid using the fast charger. A while back I was curious to see how far I can go without charging once so I charged to 100% then stopped charging it. On the 6th day I was at 20% and started getting low battery warnings. Not sure if the warning is just hard coded to come on at 20 but I kind of figured at that point it might die any time so I plugged it back in. And it's not really good for the battery to discharge it super low anyway. This is a fairly new phone mind you. My old phone would barely last a day.

 

[Lip23Pa]

In general, it is safe to charge your mobile phone battery to 100%. Most mobile phone batteries are designed to be charged to 100% without any negative effects.

 

[manly]

IPhone does as well. Called 'Optimized Battery Charging' under Battery Health, so that it will try to reduce the amount of time the battery is connected to the charger beyond reaching 100% charged state. If you do not often leave the device connected to the charger for long after reaching full charge, then this is not required.

My question is, why don't the companies build in the feature to STOP charging once the battery reaches full charge?

I'm fairly certain modern device chargers do not keep charging batteries once they are full.

I don't have an iPhone, but I don't think what Apple and Samsung are doing to optimize charging are exactly the same. Samsung stops charging at 85%, and this has a marginal benefit on overall battery longevity. This should be implemented in Android rather than being left as a manufacturer-specific tweak. Good laptops have offered this feature for a while. The drawback to this is if you have an incredibly long day out, 85% state of charge might leave you dry at night's end.

If I understand Apple correctly, they use predictive algorithms to "delay charging" once you hit 80% SoC. But by the time you wake up in the morning, I believe the SoC is supposed to be 100% (to avoid the above problem).

As @skriefal mentioned, what you do want to avoid are so-called "deep discharges," which are harmful to most battery chemistries. People may recall that NiCad rechargeables of decades gone by preferred deep discharges to avoid the memory effect. But this doesn't apply to batteries that are commonly used today. If you can help it, try to avoid draining batteries to near empty.

Having said that, it's probably not necessary to micromanage how you charge/discharge an iPhone. The batteries seem to be very durable (high cycle counts), Apple silicon is very power efficient, and years-old devices exhibit fairly graceful battery degradation.

 

[Anasabdullah]

I don't think YouTube videos are reliable sources. Trust the manufacturer's official instructions and use the original cable and power supply for charging.

 

[tcsenter]

I'm fairly certain modern device chargers do not keep charging batteries once they are full.

But they don't? If you leave the device connected, it remains at 99% or 100% after two, four, six hours, it will still be at 100%. It might shut off at 100%, but once goes below that it will start charging again.

 

[manly]

But they don't? If you leave the device connected, it remains at 99% or 100% after two, four, six hours, it will still be at 100%. It might shut off at 100%, but once goes below that it will start charging again.

In other words, modern chargers stop charging once the device is at 100% state of charge. Unclear why you stated the opposite.

IMO There are some techniques that the device OS should implement to optimize for battery longevity, but this isn't rocket science. Most people probably don't need to think about charging procedures, except for avoiding deep discharges. The other thing that should be available are reasonably-priced first-party battery swaps for the major OEMs. It's a travesty that unlike with Apple, you can't do a battery swap on a Samsung Galaxy device without going third-party. (I imagine same applies to the other Android phone makers.) Third-party, OEM authorized is okay too.

As device SoCs get more powerful relative to what people do with them (media/TikTok consumption), consumers need convenient ways to get longer-term security updates and an affordable battery replacement after a few years. Otherwise, we're tossing a bunch of e-waste into landfills for no good reason other than wasteful consumption.

 

[esquared]

In other words, modern chargers stop charging once the device is at 100% state of charge. Unclear why you stated the opposite.

IMO There are some techniques that the device OS should implement to optimize for battery longevity, but this isn't rocket science. Most people probably don't need to think about charging procedures, except for avoiding deep discharges. The other thing that should be available are reasonably-priced first-party battery swaps for the major OEMs. It's a travesty that unlike with Apple, you can't do a battery swap on a Samsung Galaxy device without going third-party. (I imagine same applies to the other Android phone makers.) Third-party, OEM authorized is okay too.

As device SoCs get more powerful relative to what people do with them (media/TikTok consumption), consumers need convenient ways to get longer-term security updates and an affordable battery replacement after a few years. Otherwise, we're tossing a bunch of e-waste into landfills for no good reason other than wasteful consumption.

Agreed.
My 2+ year old Moto Power stops when it gets to 100% and does not start charging again by itself when it drops.
I charge my phone before I got to sleep and when I get up, the phone is usually at 97%. This is the few percent it drops
just by being on for the past 6-7 hours after a full change.

 

[dlerious]

IMO There are some techniques that the device OS should implement to optimize for battery longevity, but this isn't rocket science. Most people probably don't need to think about charging procedures, except for avoiding deep discharges. The other thing that should be available are reasonably-priced first-party battery swaps for the major OEMs. It's a travesty that unlike with Apple, you can't do a battery swap on a Samsung Galaxy device without going third-party. (I imagine same applies to the other Android phone makers.) Third-party, OEM authorized is okay too.

I can set some parameters with the smart battery/charger for RC. From the Spektrum website:
Pilots and drivers enjoy the Smart advantages when using the Spektrum Smart LiPo batteries to power their RC aircraft and surface vehicles. You'll never have to set your own charging preferences for a Spektrum Smart battery until you want to. When a Smart LiPo battery is connected to a Spektrum Smart charger, its unique charging parameters and health information upload to the charger from the battery's integrated memory microchip. Through the charger you can view and, if desired, set preferences such as charge rates, so all that's required to charge the pack is connecting it to your Smart charger. G1 and G2 Smart batteries are available in 30C, 50C, 100C and 120C discharge rates for high performance and longevity.

 

[igor_kavinski]

I have two phones (Moto X (2013) and Alcatel 1X (2019)) that both take a long time to charge past 80%. It's like the electric current is breaking barriers inside the battery with great difficulty. Should I keep charging them to 100% or just leave it around 85 to 90% ?

 

[dlerious]

I have two phones (Moto X (2013) and Alcatel 1X (2019)) that both take a long time to charge past 80%. It's like the electric current is breaking barriers inside the battery with great difficulty. Should I keep charging them to 100% or just leave it around 85 to 90% ?

Might be time for a new battery, especially if you've had the Moto X battery for 10 years.

 

[igor_kavinski]

Might be time for a new battery, especially if you've had the Moto X battery for 10 years.

But what will happen if I keep using the current battery in each phone? Is it reckless to keep trying to charge them to 100%? Could it cause damage or something more serious? I've noticed that they will get hot during the initial stages of charging but once they are around 50% charged, the battery cools down. What is this phenomenon?

 

[dlerious]

But what will happen if I keep using the current battery in each phone? Is it reckless to keep trying to charge them to 100%? Could it cause damage or something more serious? I've noticed that they will get hot during the initial stages of charging but once they are around 50% charged, the battery cools down. What is this phenomenon?

Sounds like it charges at a faster rate in the beginning and starts dropping down at certain points, being a trickle charge near the end. If ambient temps are high, battery might charge slower. Haven't really had a single phone for a long time. Oldest is probably a Moto G5 I think, been sitting for 5 years since I cancelled, so battery is likely sitting at 0.

 

[Lost_in_the_HTTP]

I have a Motorola Stylus that takes about 2 hours to charge to full. It lasts generally 6-8 days before it gets below 20%.

I also have a Samsung Tab A that takes a full 5 hours to charge and last generally 4-5 days before getting below 20%.

I obviously don't use either for heavy use. Both are mostly on standby and only get used to check something quick while away from a PC.

 

[Fallen Kell]

Long and short, it depends on the battery and the charging circuit. Some batteries have built in charging protection circuits, others do not and rely on the charger/device to prevent problems with charging at 100%. A good device will detect the 100% charge and then prevent additional charging until the battery is used to some extent (ideally something lower than 80% for getting the most longevity of the battery, but most will allow charging at just a couple %). Charging cycles are what shorten the life of the battery, so the more it cycles into charging mode, the shorter the lifetime of the battery (not the shorter the "charge", but the ability for the battery to accept a charge, which in a sense does shorten the charge capacity of the battery as parts of it wear down and stop taking the charge).