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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?

#81

Post by hilux »

Kirby64 wrote: post #39
p1necone wrote: post #23

Earlier quoted context omitted.

> Those are replaceable and cheap to replace every couple of years. If you specifically seek out devices with cheap replaceable batteries, sure. But this isn't the case with a lot of devices.

The cost to replace the battery on iPhones, which most people would consider to be “difficult to replace” is only $100 directly from Apple. Really seems like paying an extra $100 every 2-3 years is a decent deal for something that has 20% more battery.

Even better - for some models it's $69 from Apple, and around $50 from third-party providers.

Source: I replaced my iPhone battery last week.

Re: Charging a lithium battery to 80% only?

#82

Post by justworkout »

vGPU wrote: post #6
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…

Even my iPad has horrible background drain. My iPhone is the only device I have that I can calmly leave at 15% when I go to bed and know my alarm will still work in the morning.

I had an iPad that I bought 5? years ago and I could leave that thing in sleep mode for literal weeks at a time and I'd still have a mostly full charge.

I "upgraded" to a Pro 2 years back and the first thing I noticed was it'd go from a 100% charge to 60% to even 40% overnight. All apps closed, freshly rebooted and did nothing but charge it the previous night before unplugging it.

A lot of comments online say "This doesn't happen. You're doing something. And it's certainly not wifi and bluetooth because those don't use battery while idle so do NOT turn those off!" I tried everything that was recommended, turning off iCloud, uninstalling random apps, etc.

Then I got into a habit of turning bluetooth off every night and my battery would only drain about 4-6% a day while idle. Turning off wifi as well and I get about 2-3% drain per night. I have no clue what Apple is doing, but when putting my iPad to sleep at night with any sort of wireless on, the device connects to every fucking thing it can find but wouldn't do while awake. I never even synced my Airpods with my iPad and made sure to delete them when they did connect, but still, if I leave bluetooth on before going to bed, my iPad will connect to my airpods while they're in the case, drain them to 0% (even after fully charging the Airpods before sleeping. It's not even possible to drain the case's battery with actual usage that fast!), then drain 40% of its own battery.

I can't make sense of it.

In short, turn all wireless off when you're done for the day. iPads/iPhones are annoying in that you can't turn them off from the drop down menu though, so you need to go through settings or make a shortcut.

Re: Charging a lithium battery to 80% only?

#83

Post by fragmede »

trustingtrust wrote: post #22
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…

Almost nobody cares about saving batteries. Those are replaceable and cheap to replace every couple of years. Innovating more battery life and leaving 20% battery life on the table sounds extremely pointless for what costs 20-30$ a year but lets you use the device all day instead of just shutting before the end of the day.

I'm an "almost nobody". I care about saving batteries. I get all the dead disposable vapes my friends will give me so I can recycle the batteries in them. Lithium is a limited resource and one day we're not going to have more to dig up out of the ground. There are others like me out there, I just need to find them.

Re: Charging a lithium battery to 80% only?

#84

Post by fomine3 »

I really want 80% limit feature on TWS earphones. It has small battery, perhaps fully utilize battery capacity for longer battery life, harder to replace battery (especially with waterproof). I'd like to have a 80%-100% slide switch on the case, but it would be too nerd feature.

Re: Charging a lithium battery to 80% only?

#85

Post by Reason077 »

numpad0 wrote: post #73
Reason077 wrote: post #64

Earlier quoted context omitted.

Most likely you get towed to the nearest charger on a flat-bed truck. But portable chargers (with batteries or diesel generators) on the back of trucks or vans also exist. Some EVs also support power output (V2x) from their charge ports, allowing you to charge up one vehicle from another.

What exactly is the reason the car shouldn't be towed for regen? It seems a dead EV can just be towed to the midpoint between origin and the nearest charging station, then can be driven to the station using regen'd charge.

If the EV is truly dead then you may not even be able to put it in Drive mode until it’s plugged in, so regen wouldn’t be possible.

But sure, assuming you have enough power to put it in drive, there’s no reason that you can’t do this. There’s YouTube videos where people have tried it successfully.

My understanding is that manufacturers don’t support or recommend this method, though.

Re: Charging a lithium battery to 80% only?

#86

Post by xvedejas »

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…

Because of the flatness of the voltage curve, limiting your charge to the middle range makes the state-of-charge estimation a much more difficult problem (less voltage signal). So there's actually a trade-off between longevity and accuracy of charge reporting.

Re: Charging a lithium battery to 80% only?

#87

Post by gamblor956 »

artimaeis wrote: post #16
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…

I just picked up my 2017 iPad Pro. It was last charged Nov 15. Been sitting by the bed mostly unused since. Currently at 80% charge. I haven’t experienced what you’re describing on an Apple device since they switched the laptops away from Intel chips. In my experience, the OS does matter. I can’t believe how bad the rest of the industry is at this. Amazon’s Kindle line is incredible at this IME, but those are pretty…

I recently picked up my Surface 3 for the first time since 2017. It had a 66% charge from the last time I used it...

It's not so much the OS as the device firmware, since the Surface 4 runs the same OS but has significantly worse battery performance.

Re: Charging a lithium battery to 80% only?

#88

Post by nottheengineer »

trustingtrust wrote: post #22
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…

Almost nobody cares about saving batteries. Those are replaceable and cheap to replace every couple of years. Innovating more battery life and leaving 20% battery life on the table sounds extremely pointless for what costs 20-30$ a year but lets you use the device all day instead of just shutting before the end of the day.

My Oneplus 5T got replaced because it has a small crack in the screen so it's impossible to disassemble without breaking the screen. I used ACC to only charge that to 90% so I could get three years out of the battery instead of just two.

I'll probably get a fairphone next so I don't need to worry about this. But the people with glued-in batteries definitely have to.

Re: Charging a lithium battery to 80% only?

#89

Post by negative_zero »

There is so much confusion, misinformation and naive testing about this topic. I've only learned about this "80% battery thing" when researching EVs recently and it seems to have been (maybe) spawned by the Nissan Leaf many years ago.

And now it's appearing on HN seemingly once a week. What has changed? Is someone running an information(or disinformation) campaign? Blog or app to promote?

I've not spoken earlier for fear of being downvoted into oblivion: I am sorry to say, but this 80% nonsense is just ... terrible advice and is 90% wrong. Like "skipping a daily coffee will let you retire 10 years sooner" wrong. (And all these lovely graphs I see thrown around are from poorly setup and poorly controlled tests using small samples or maybe even they're faked idk).

To be horribly simplistic about it, the biggest factor in battery ageing is thermals. So if you want actionable advice on increasing the longevity of your battery (in the mobile phone context):

Don't let it get hot, which means things like:

* Take off that awful plastic insulator you call a phone case. (But we need phone cases)

* Charge it slowly. Lower charge rate = less heat = happier battery. (But people love charging their phone in 1 minute)

* Charge at human ambient temperature. (But on my bed, in the sun is easier)

I guess those are inconvenient and poor sound bites. I'm sorry, but consumer devices (especially phones) have poor thermals and the environment they're subjected to sucks. That's just a fact of life (and economics and physics).

Very simplistically, the only way "charge to 80% only" *might* be helping you is by keeping the battery cooler (In which case the above advice is much better).

Re: Charging a lithium battery to 80% only?

#90

Post by JBiserkov »

artimaeis wrote: post #16
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…

I just picked up my 2017 iPad Pro. It was last charged Nov 15. Been sitting by the bed mostly unused since. Currently at 80% charge. I haven’t experienced what you’re describing on an Apple device since they switched the laptops away from Intel chips. In my experience, the OS does matter. I can’t believe how bad the rest of the industry is at this. Amazon’s Kindle line is incredible at this IME, but those are pretty…

And that's without power saving mode? Impressive!

Have you configured anything like "disable background network activity"?

Do you force close the apps?

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