If lithium batteries last more than ten years why do phones' die in two/three?

Don B. Cilly

Energetic energy padawan
(I've asked Mother Goo...gle, but I' can't seem to find any useful information).
Just as the title says. No matter how well you treat your phone's battery, two-three years is what you'll get out of it.
And it seems no one expects it to last longer, either.
My phone's battery easily lasted a week when it was new - I didn't use it that much, no.
After a year it was down to, say, four days. After two and a half, it was down to next-to-nothing.
I got a new one. Not a very good one either...

Anyway, our Lithiums are supposed to last 10, 15, or more years. I wonder what they actually last - even with proper care.
 

camelCase

Solar Enthusiast
The chemistry of the batteries in your phone are quite different than the Lithium Iron Phosphate batteries which are most commonly used for solar battery banks. A phone battery is typically has significantly reduced performance after 1000 charges where as LiFePo4 batteries should be good for several times that or even longer.

Phone batteries are subjected to high charging rates, being held at full charge for many hours and high heat, too, which does not help.
 

camelCase

Solar Enthusiast
But even if you do treat them well (I did), they won't get to four years' battery live. Like, ever.
My cell phone's battery has 90% capacity after 3 1/2 years because I'm really gentle with it. I only charge it to 80% and plug it in before it gets to 30% as much as possible.

The best thing you can do for your phone is to not leave it plugged in over night.
 

Don B. Cilly

Energetic energy padawan
OK, lithium-ion doesn't last that long. But...

A phone battery is typically has significantly reduced performance after 1000 charges

I used to charge my phone every six-eight days. Call it five, it's just over 70 cycles a year. Some 14 years to get to 1000 cycles.
Now...
I only charge it to 80% and plug it in before it gets to 30% as much as possible.

I never let it discharge much either. Say 20%. But I did charge it to 100% of its BMS. I guess that's not optimised for long life, though, as it would sell less batteries/phones ;·)
 

MurphyGuy

Solar Addict
There are a couple reasons:
1) The battery chemistry. LiFePO4 cells can last 10 years but are too bulky for consumer electronics. Some Lithium Ion cells in things like Tesla's PowerWalls have a 10 year warranty, but won't actually last that long if fully cycled every day. Tesla is betting that most home users won't fully cycle their batteries.

2) With solar batteries, we generally don't charge and discharge to the battery chemistries limit.. Instead, we pull back from the extreme ends. A lithium ion battery with a voltage range of 3 to 4.2 volts (think consumer electronics, 18650's, etc) will last about 300 to 500 cycles if fully charged and fully discharged each cycle.. In consumer electronics, battery life, as in how long before you have to return to the charger station, is everything, so with that in mind, consumer electronics generally allow their batteries to charge and discharge to the maximum limits..
If you want to extend the life of your consumer battery, don't charge your laptop beyond 90% and don't run it down under 15%.. and don't ever leave it in a hot car or other place where it will experience high temperatures.

I have a Samsung tablet that is 2 years old now and the battery shows ZERO degradation based on the software app I have installed that monitors it. I also have an app that sounds a loud alarm when the charger has reached 80%, and I almost never let it drain below 20%. Its much better to give your electronics daily little "charge boosts" so they never get fully charged and are never allowed to get to zero.

Fully charging a lithium ion battery is the fastest way to wear it out.
The cooler a battery is kept (above freezing) the longer it will last.
Discharging a lithium battery to zero is bad for it, but not as bad as charging it all the way up.
Fast charging is bad because it generates heat, which accelerates aging.
 

Short_Shot

Photon Sorcerer
Daily charging.

Phone uses all of the battery capacity.

Discharge current can often exceed what would give you a long life.

Heat.

Not too complex.
 

Don B. Cilly

Energetic energy padawan
Fully charging a lithium ion battery is the fastest way to wear it out.

So the BMS (or whatever it's called) on phones is set to minimise battery life, so - unless you want to take a hammer and chisel to it in order to change it (like the newer ones require) you have to just buy a new one.

Hell, I remember trying to find a way to disable charge and just keep data flowing through USB.
On Android, you just can't :·/
 

Short_Shot

Photon Sorcerer
So the BMS (or whatever it's called) on phones is set to minimise battery life, so - unless you want to take a hammer and chisel to it in order to change it (like the newer ones require) you have to just buy a new one.

Hell, I remember trying to find a way to disable charge and just keep data flowing through USB.
On Android, you just can't :·/
Essentially yes.

They definitely want to to buy a new phone every year.
 

MurphyGuy

Solar Addict
So the BMS (or whatever it's called) on phones is set to minimise battery life, so - unless you want to take a hammer and chisel to it in order to change it (like the newer ones require) you have to just buy a new one.

Hell, I remember trying to find a way to disable charge and just keep data flowing through USB.
On Android, you just can't :·/
Its set to maximize talk time.. although this has the effect of minimizing battery cycle life.

But its not beyond your control.. you can download an app like I did that sounds an alarm when its time to unplug it at whatever percentage you set..
It should be noted that while there is no automatic way to tell the BMS to stop charging early, (no app or anything like a setting you can control), there are hardware solutions that plug in between your phone and the USB charging cord that will disconnect the charger.. I think they're like $30 or something.
Here's a link to one I just found for you:

Products like that can extend the life of your battery by two to four times longer.. and since its USB, it should work on everything from your phone and tablet to your flashlight and ear buds. What you sacrifice is the time you can go between charges. In my case, my tablet lasts for two or three days depending on how often I decide to play Sudoko.. so if I bought that device, I could just plug it in every night and go to sleep without worrying that its going to charge the battery too high or that the noisy charge alarm app is going to wake up the whole house.
 
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