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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?

#71

Post by sprokolopolis »

On Android, I use a terminal script called Advanced Charging Controller (ACC) to automate keeping the battery under 80% and some other battery saving tweaks. It allows you to charge to any value (like 80%), then stop charging until it discharges to another set value, which triggers it to start charging again. That was you can keep it between something like 70% and 80% while you leave it charging over night. It also has settings to keep the batter under a specified temperature and trigger cool-down intervals if it gets to a particular temperature. It can use a job scheduler to switch between different profiles for different days, or events. There are also some frontend apps, which let the user control the script with a more friendly GUI ("AccA" or "ACC Settings").

Link to the script: https://github.com/VR-25/acc This does require root permissions, though.

Re: Charging a lithium battery to 80% only?

#73

Post by numpad0 »

Reason077 wrote: post #64
Gigachad wrote: post #59

Earlier quoted context omitted.

What happens if you actually do fully drain an EV on the road? How do you recover from that situation? Normally you’d just have to get a container of fuel delivered to you.

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.

Re: Charging a lithium battery to 80% only?

#74

Post by tjoff »

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…

You are right but I disagree.

Yes, devices do not charge batteries to 100% as that is directly damaging. And they don't discharge to 0% for the same reason.

So they charge to something slightly less. But that slightly less is for all intents and purposes the only definition of 100% we, as end users, have.

It's like saying that your CPU is actually only running at 70% clock frequency but overclocking it to 100% would require massive cooling and reduce the lifetime to months.

I agree a better definition and preferably one directly comparable to all brands and battery types were available, but I'm not aware of any and I'm sure that even if we had it you wouldn't trivially be able to get that information.

Noone should ever charge to more than 80%. That is short sighted and environmentally moronic. After less than two years a device will have more capacity at 80% than the same battery will have at 100% if it was charged to 100%.

Re: Charging a lithium battery to 80% only?

#75

Post by djmips »

talldatethrow wrote: post #67

The battery in my pixel 4xl failed two times under warranty and then a third where googles service provider wouldn't do it again for me. (The ribbon connector is actually what fails). So I went to Amazon and bought a $14 kit that came with a battery AND tools. Did it myself in 15 minutes. (Whereas the UBreakIfix vendor took like 2 hours of my time between dropoff and pickup). The Amazon battery has lasted longer than…

You did all this in 15 minutes? https://www.youtube.com/watch?v=m1gVWGAw8do

Let me guess, the back cover wasn't stuck on very well from the repeated battery replacements.

Re: Charging a lithium battery to 80% only?

#76

Post by speedgoose »

ra wrote: post #69

We just got a Tesla model Y. When we picked it up, they told us to charge it up to 100% at least once per week. Is there something different about these batteries?

You probably have one with a LFP battery.

They have a different chemistry that is cheaper, have a lower energy density, are less powerful, don’t like cold, but that can often be charged to 100%.

The reason you need to charge it to 100% so often too is that it’s the voltage on a LFP battery is all over the place and the battery management system (BMS) has a hard time to keep track of the remaining capacity. Those system usually rely on the voltage but they can’t on this kind of battery. So charging to 100% will let the car know an accurate battery state of charge: full.

I have a model y with a classic LG lithium battery and I almost never charge to 100% and the car is discouraging charging that high in its user interface.

https://en.m.wikipedia.org/wiki/Lithium_iron_phosphate_batte...

Re: Charging a lithium battery to 80% only?

#77

Post by nortlov »

ra wrote: post #69

We just got a Tesla model Y. When we picked it up, they told us to charge it up to 100% at least once per week. Is there something different about these batteries?

Some models (RWD?) are equipped with LFP (lithium iron phosphate) batteries. Tesla recommends setting a charge limit of 100% and, as you mentioned, charging up to 100% at least once per week.

https://www.reddit.com/r/electricvehicles/comments/10ji8yk/l...

Re: Charging a lithium battery to 80% only?

#78

Post by beefnugs »

This can't really be that big a deal. My framework laptop used to have a setting right in the bios about not charging past 60% if you plan to keep it plugged in all the time... at some point they just bug broke that feature and never bothered to fix it ever again. These are smart people and I trust that it can't really matter that much or they would have fixed it by now

Re: Charging a lithium battery to 80% only?

#79

Post by hilux »

datameta wrote: post #37
fiddlerwoaroof wrote: post #25

Earlier quoted context omitted.

Replacing an iPhone battery is cheap, especially compared to replacing the whole phone: at the Apple Store it’s either $99, $69 or $49 and I’ve had other stores do it for like $40. That’s not too bad for a once every couple years cost.

Cheap for the wallet, but not the biosphere. Unless you mean to imply that people would get new phones less frequently?

It's well-established that iPhones have longer average lives than Android phones.

Re: Charging a lithium battery to 80% only?

#80

Post by thrtythreeforty »

mcronce wrote: post #4
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…

FWIW, I can't speak to other operating systems, but with Linux (maybe requiring cooperative hardware? I'm actually not sure) you can configure it to stop charging at a certain % if the charge controller doesn't have reserve. I can find a link if you're interested; IIRC it was easy to setup and easy to temporarily disable if you need to fully charge for e.g. a long flight without outlets

This does require firmware support but it's pretty seamless in Plasma. It requires a root password which is slightly irritating. At one point I went through the PolicyKit contortions to allow normal users (me) to change it.
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