They say laptops, phones and tablets and other devices should be charge to 80% and no more, that Lithium-ion batteries hate being at 100% even 90% that you will destroy the battery if the laptops, phones and tablets and other devices are always plug in at 100%
Saying that you should never use laptops, phones and tablets and other devices plug in when it is charge take it off the charger do not use it well it is plug in as you will destroy the battery life. Saying that Lithium-ion batteries hate being at 100%
They than go on to say to maximize the health of the battery it should only be charged to 80% and no more.
It depends on how sophisticated the charge controller is.
For example, new Apple devices only charge to 70%, if they detect a pattern of always being used plugged-in.
Lithium Ion batteries are very susceptible to overcharging, and even a tiny amount of charging when they are “full” will lead to damage.
Possibly some outdated info, but Li-ion batteries greatest life is at 40 % state of charge. Unlike the previous generation of rechargeable (NiCd and Nimh), Li-ion batteries are not really limited by cycle life. Cycle life is just an industry standard from those other 2 formats, and why it is still used though it is really irrelevant with li-ion. The real killer of Li-ion is heat and time spent at the state of charge. But since cycle life is the standard, the estimated damage of heat and time at states of discharge are equated to a number of cycles.
Heat is self explanatory, the hotter it get the worse it is. As for time at state of charge. As I stated the longest life for a Li-ion battery would be at 40%.
The life drops off as you go either way, towards 0% and towards 100%, in a sort of parabolic fashion. it’s just not the state of charge but the time spent in that state that matters. Additionally the Li-ion batteries we get can’t get to true 0% or true 100% as that would greatly shorten their life and thus are circuit limited to an artificial 100% and 0%. So the artificial 0% and 100% are the most damaging to the life of the cell that we can achieve in consumer electronics. And the longer the cell spends in that range of charge the shorter the life will be. So keeping a device plugged in (at 100%) would put it in one of the positions for a short battery life. Stopping at 80% really gives a significant longevity advantage.
I understand that EV car manufacturers set the 100% and 0% points such that there’s a small margin on the outside of that range. But it isn’t a 20% margin, so not 100% when it’s really 80%.
Some phones and computers have a setting to save the battery that will stop charging it at 80%. My phone can do that, or it can learn your usage pattern (when you wake up) and go to 80%, and then do the last 20% right before you wake up.
Chemically: Sort of true whatever your device sets as it’s 100% is not true 100%. The battery cell itself can go higher, but it is software locked out - you will never get to true 100% due to that. Same with 0% is not chemically true zero. However using that extra capacity can greatly shorten the battery life. This is why some Li-ion batteries can be expected to last longer then others, it’s how far they push into that extra capacity, more push = shorter life.
Software: The initial 100% you are given is, as I understand it, mostly going to be it’s 100% level. However there are exceptions. Tesla has unlocked extended battery capacity via software update on occasion on their EV’s. This basically moved the artificial 100% and 0% to give more range, presumably at the cost of ultimate life of the battery. They did this for one during a Florida hurricane evacuation. Apple reconfigured it’s battery percentage, I think on a iPhone, to make it appear that the phone battery is lasting longer, so made the percentage scale non-linear. That didn’t add capacity, but when your phone said 80% it may only be at 70%, so it appears it is lasting longer. They did that to counter complaints about low battery life. I don’t know of any device that will fool you into accepting 80% (or so) as 100% and displaying 100%, but IDK. Though if the device can be updated yes that seems easy enough to do.
Extend M4 iPad Pro Battery Lifespan With This New Feature
Apple’s new M4 iPad Pro and M2 iPad Air models feature a battery health setting that is new to iPads and when enabled prevents the devices from charging beyond 80% at all times, which can extend battery lifespan.
My iPhone 14 will notify me of “Optimized battery charging”. When I put it on the charger at night, it says it will time the charging so it hits 100% at 8:00AM. My wife’s batteries on iPhones over the years have often died much faster than my iPhones, and I’m not sure if that’s from excessive use (more charge cycles) or from having it constantly plugged in, even when using it.
My Tesla has an alleged range of 500km (300mi) at 100%. The suggestion when I bought it was to charge at 80% usually. For road trips and other longer drives, I can charge to 95% or 100% (Set on car’s console). It was also recommended to avoid habitually going below 20% to 10%. I don’t believe they lie about capacity to any great extent- you’re not going to drive dozens of miles on a 0% battery.
The note was that this does not kill the battery if you happen to do this. You can even do it quite often. It was just a warning that the more often you do this, the faster the battery will deteriorate and hold less charge. Same applied ot fast charging - a battery habitually fast-charged will deteriorate faster than one typically slow-charged. I typically charge to 80%. I eventually took to not charging every night, maybe every 2 or 3 days, unless I know I’ve got a lot of driving the next day. After 5½ years it still charges to 95% of original depending on temperature.
Some of the newer Teslas come with LPF batteries, and the advice for them is to charge to 100% since this does not have a negative effect on the battery.
The bit about extending range during a hurricane was due to a peculiarity of Model S batteries. Many of the lesser S’s (!) had the same battery pack as the long range ones. They just software limited the pack to 60 instead of 90kWh. It was cheaper than building two different packs at the time. When leaving Florida was urgent, those 60’s were given a one-time update to go the full range of the battery for a few days. (They did something similar for the 3 in Canada. To qualify for the federal incentive, Tesla needed to sell a model for $C45,000 or less - about $US32,500. They sold a 3SR with the battery software limited to 145km -“do NOT buy this, but we offer it!” - and the vow the range could never be unlocked. This qualifed the 240km Model 3 for the subsidy)
Also note that there is no “charge gauge” on batteries. Tesla uses a battery strength test; it needs to calibrate every so often to what a well-charged battery and a well-discharged battery are. Advice is every so often, let car sit at 80% charge or more for 3 hours unplugged. Also, every so often let the car sit for 3 hours at 20% or less unplugged. This gives a more accurate picture of battery charge. I have heard (never tested) that when the battery indicates 0% it may still get you a bit further (a few miles according to some posts) but then, the same happens with a gas tank. Like that gas tank, I wouldn’t rely on it.
This was once thought to be the case but now in question. It does seem it’s not the fast charge so much but more the heat that fast charging causes. With proper thermal management it appears that fast charging does not significantly reduce battery life. But even with thermal management there still is a small hit on life, but just much smaller then without.
I also read today that allowing the iPad or iPhone to drop below 20% before putting it on the charger is bad for battery health. And allowing the iPad or iPhone to drop to 1% or 0% will really destroy the battery health.
ALL charging is bad for battery health.
But, it’s a fool’s game to try to micro-manage your charging. Just use your device and forget about it. By the time the battery is dead, it will be time to upgrade anyway.
All of the lithium-ion batteries I own are in devices (iPhone, iPad, notebook computer, portable USB battery pack, etc), so I assume the manufacturers know better than me how to manage charging. So I plug in or recharge whenever I want.
What I am saying it it appears that the heat produced by fast charging is the major factor in shortening the life, the fast charging itself does not seem to be a major factor. So if you can keep it cool while charging it should last longer. So extending it to an Apple device, Since there is no thermal management, a fast charge will created more heat and thus will shorten it’s life.
Why do you think that Apple doesn’t have battery thermal management in their charge controllers?
AFAIK, all current Apple devices have a battery temperature monitor, and that is used to throttle the charge current.