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Charging a lithium battery to 80% only?

electronics.stackexchange.com

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Re: Charging a lithium battery to 80% only?

#301

Post by Perz1val »

venj wrote: post #169
TerrifiedMouse wrote: post #150

Earlier quoted context omitted.

I wonder how many products have components that downgrade under specific situations and they never explicitly tell the customer - and most customers don’t ask because it’s “complicated tech” they don’t want to know about it.

I think a lot of laptops do this because their cooling system is too weak for the CPU. The Lenovo Thinkpad t480s comes to my mind: with factory settings, the CPU was unable to reach its advertised boost frequency nor maintain its max non-boost frequency for more than a few minutes. After 5 to 10 minutes, the machine was usually running at 300/400mhz under its advertised clock speed. Undervolting helped a lot but coul…

This is likely the case with all but gaming laptops. Most users won't care about performance under consistent, heavy workload, as much as it loading that .docx in 2 instead of 6 seconds. That burst of performance is what makes the system feel snappy and fast. If the user is happy, it was well worth the money too.

Re: Charging a lithium battery to 80% only?

#302

Post by 1970-01-01 »

dheera wrote: post #46
p1necone wrote: post #21

Earlier quoted context omitted.

I'm pretty sure most (all?) manufacturers already do (the first part of) this. 100% can't be the point at which the battery literally stops taking new charge - if you did that they'd catch fire all the time. It's just that the manufacturers idea of what "100%" should be generally skews more towards the immediate battery life end of the tradeoff, whereas some users prefer to have "100%" closer to the maximizing long t…

> I know my android phone will let you cap max charge at an arbitrary level Yeah I used to have old Pixel phones as Home Assistant clients on my walls until they all started bulging one by one and I had to treat them as a fire hazard. I now use Samsung tablets, ironically, that have a cap at 80% feature and they seem to be doing fine.

>I now use Samsung tablets, ironically, that have a cap at 80% feature and they seem to be doing fine.

Yes, this feature is one of the most underrated features on Samsung devices. Massively underrated.

Re: Charging a lithium battery to 80% only?

#303

Post by danecek099 »

_yb2s wrote: post #299

I use a Chargie (chargie.org) hardware device to limit charge on my devices to 80%, and the batteries last nearly forever. Currently typing this on a 4 year old iPhone with like new battery function. I highly recommend these, I’ve been using them since they were first sold. I have no affiliation, but am a very satisfied customer. For my Macbooks I use an app called Al Dente. I still have have 2016 MacBook with like n…

Wow I didn't know chargie.org existed! I'm happy to finally see a device like this on the market.

I've had the same idea and created a device exactly like this as a high school project back in 2018, but didn't push it further

Re: Charging a lithium battery to 80% only?

#304

Post by throitallaway »

Arainach wrote: post #3

I've given up trying. If a device is willing to lie to me and only charge to 80% while saying it's charged, great, but all of this "try to stay in a range" logic flies in the face of reality. Every device I use besides my cell phone, Nintendo Switch, and Nintendo 3DS has atrocious power drain when not in use. OS does not matter. Windows laptop, Linux laptop, ChromeOS laptop, Android Tablet, Amazon Tablet, you name it…

Do you leave your Nintendo Switch in standby mode or hold the power button for a few seconds for a full power off? If I don't do a full power off, the battery is gone after a few days in standby mode. It's really annoying when I forget to do it and am welcomed by a dead switch. My Switch is often outside of WiFi connectivity, and I wonder if it's constantly searching for a known network to latch onto.

Re: Charging a lithium battery to 80% only?

#305

Post by throitallaway »

vladvasiliu wrote: post #226
lopis wrote: post #143

Earlier quoted context omitted.

An android device in standby in airplane mode will last a week in a single charge easily, in my experience. But if you have radio on, yeah, 2 days tops.

What device is that? It doesn't sound all that exceptional. The longest I've had my iphone 14 pro unplugged was around 3 days, with very light use (I'd say 2 hours of active use, randomly browsing HN and reading a newspaper on its app). It barely went below 50%, with all radios on.

This is going to depend heavily on a number of factors. Background apps, processing notifications, screen brightness, signal strengths, etc. all play a role.

Re: Charging a lithium battery to 80% only?

#306

Post by calamari4065 »

p1necone wrote: post #21
belltaco wrote: post #14

I wish they would label it so that it shows 100% charge when it's actually charged 80%, and then give an option to 'overcharge' a configurable amount till 125% (the current 100%). That way it will make people aware that they are reducing the battery life by overcharging, and be picky when they overcharge. But this won't happen because reduced battery life is a big direct and indirect(by reducing performance like Appl…

I'm pretty sure most (all?) manufacturers already do (the first part of) this. 100% can't be the point at which the battery literally stops taking new charge - if you did that they'd catch fire all the time. It's just that the manufacturers idea of what "100%" should be generally skews more towards the immediate battery life end of the tradeoff, whereas some users prefer to have "100%" closer to the maximizing long t…

I think there's some confusion on what this actually looks like on the manufacturer's end.

When charging a lithium battery, your termination point is tied to only one value: voltage. 4.2v per cell is generally considered the maximum safe termination voltage. This is the theoretical 100% charge. And yes, if you keep pushing volts in, it will keep taking them until the call fails catastrophically.

Personally, I use 4.1 as my termination voltage. That's somewhere around 90-95%. You 'lose' a little of the maximum capacity, but lifespan is increased. I find it's fairly common for battery charge controllers to use either 4.1 or 4.2 as their default termination, but it's almost always selectable. You have to make a decision somewhere.

The flaw in this is that you're trading away a banner spec for something that users won't appreciate. You have to decrease the stated capacity and runtime of your battery in exchange for an indefinable amount of extra total lifetime. That's not something that consumers can/will take into account. They just look for the device with the most mAh or runtime.

Re: Charging a lithium battery to 80% only?

#307

Post by fyokdrigd »

Tagbert wrote: post #297
nxobject wrote: post #257

Earlier quoted context omitted.

Well, duh. You're holding it wrong. /s

I never could get that to not work. No matter what I did the signal didn't degrade.

because by the time you tested they had already boosted signal power beyond all guidelines

Re: Charging a lithium battery to 80% only?

#308

Post by LeifCarrotson »

Arainach wrote: post #3

I've given up trying. If a device is willing to lie to me and only charge to 80% while saying it's charged, great, but all of this "try to stay in a range" logic flies in the face of reality. Every device I use besides my cell phone, Nintendo Switch, and Nintendo 3DS has atrocious power drain when not in use. OS does not matter. Windows laptop, Linux laptop, ChromeOS laptop, Android Tablet, Amazon Tablet, you name it…

If you shut down your Windows laptop or Linux laptop completely, or remove the battery, the battery will not drain.

I've accepted that manufacturers cannot or do not care or will not give me instant wake without atrocious power drain during sleep. Modern solid-state storage boots up really fast, and my browser, IDE, text editor and other tools are pretty good at restoring my working state after boot.

Re: Charging a lithium battery to 80% only?

#309

Post by kube-system »

TerrifiedMouse wrote: post #150
Reason077 wrote: post #135

Earlier quoted context omitted.

> "What Apple did was clock down the CPU of iPhones with degraded batteries in order to reduce peak load" It wasn't what Apple was doing that was the problem, it was the fact that they were initially quite secretive about it! People just started noticing their phones slowing down without explanation. Now days iOS tells if your battery no longer supports peak performance, which is the right thing to do. > "Yes, they s…

I wonder how many products have components that downgrade under specific situations and they never explicitly tell the customer - and most customers don’t ask because it’s “complicated tech” they don’t want to know about it.

Clog the heatsink on just about any PC and it'll happily and silently thermal throttle itself.
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