Prolong battery cycle life by limiting charge to 80%?

[fuzzybabybunny]

I'm reading this article:

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

I lithium battery at 4.20v has 300-500 cycles. The same battery at 4.05v has 850–1,500 cycles, so triple the number of cycles.

My Samsung S5 currently charges the battery to 4.20V and keeps it there when plugged in.

Wouldn't it make sense then to get an app for your phone and/or laptop that limits all charging to 80%? If you really need a full battery for the day you can disable the app and allow it to charge to 100%, but for most of the time when you leave your device connected to the wall at your desk you can keep the app enabled.

 

[Red Squirrel]

I think for stuff like phones it's fine as you are constantly using it. I tend to plug mine in when I'm at the computer as I just leave a cord nearby, same at work. When it hits 100 or close I unplug it and I know I'm good for over a day.

I would also presume that the phone itself already has some limits built in, such as not allowing over charging or over discharging.

It would be interesting though to see how different phones handle this. Some may be better than others.

 

[Sonikku]

I charge my phone about once a week. I could keep it 6 to 10 years.

 

[lxskllr]

I think that's technically correct, but I'm not sure how much it matters. When I first got my S5, I short stroked the charge cycles, but I got lazy, and just started letting it do its thing. After 2.5 years, my battery was still acceptable. This was charging it at least once a day, sometimes more. When batteries cost ~$10, it probably isn't worth concern.

 

[John Connor]

I just charge my phone once a day to 100%. The phone is two years old now and the battery seems to be holding up so far.

 

[manly]

I think that's technically correct, but I'm not sure how much it matters. When I first got my S5, I short stroked the charge cycles, but I got lazy, and just started letting it do its thing. After 2.5 years, my battery was still acceptable. This was charging it at least once a day, sometimes more. When batteries cost ~$10, it probably isn't worth concern.

Most high-end phones don't have user-replaceable batteries anymore. So optimizing battery lifetime is definitely useful. Apple's battery service is $80 so it's not a trivial expense.

As for how to do that, the software really should do it automatically (doesn't one flagship phone now do this, or am I just thinking of the newest Qualcomm SoC?). By necessity, this is done in battery EVs. But planned obsolescence is party of Apple's business model, so I doubt that'll change soon.

 

[fuzzybabybunny]

Most high-end phones don't have user-replaceable batteries anymore. So optimizing battery lifetime is definitely useful. Apple's battery service is $80 so it's not a trivial expense.

As for how to do that, the software really should do it automatically (doesn't one flagship phone now do this, or am I just thinking of the newest Qualcomm SoC?). By necessity, this is done in battery EVs. But planned obsolescence is party of Apple's business model, so I doubt that'll change soon.

I mean, it's clear that the battery chemistry prefers to NOT be at 4.20V. Any battery app can report back the voltage of the battery and I'm willing to bet that all new phones charge the battery to 4.20V and keep it there since that's "100%."

You'll get 300-500 cycles at 4.20V. That's only a year of use before your capacity drops dramatically. Versus triple the number of cycles if you kept your battery at around the 80% mark.

 

[manly]

Here you go:
https://android.gadgethacks.com/how...oid-device-avoid-excess-battery-wear-0176280/

I thought one of the OEMs (or Qualcomm) had implemented this recently but I can't find it right now.

 

[John Connor]

Damn, requires root. I wanted to root, but it looked like a major PITA and I didn't want to F my phone up. Besides, I read a rooted phone is more vulnerable.

 

[Red Squirrel]

You would think that being able to set a limit would be something they'd put in the settings. Default it to like 4.10v and add a max to like 4.30 or something with a warning that it's not recommended. My phone is at 94% and idle battery voltage was 4.19. I just put it on the charger and it's at 4.40 now. That seems kinda high.

 

[jlee]

You would think that being able to set a limit would be something they'd put in the settings. Default it to like 4.10v and add a max to like 4.30 or something with a warning that it's not recommended. My phone is at 94% and idle battery voltage was 4.19. I just put it on the charger and it's at 4.40 now. That seems kinda high.

Charging voltage is higher than resting voltage (otherwise it wouldn't charge).

 

[fuzzybabybunny]

Charging voltage is higher than resting voltage (otherwise it wouldn't charge).

Resting voltage of 4.20 is still high.

 

[zerocool84]

When you fully charge your smartphone battery, it's not truly at 100% anyways, neither it at literal 0% when it shuts off either. Their are built in protections nowadays on modern smartphones for that.

 

[fuzzybabybunny]

When you fully charge your smartphone battery, it's not truly at 100% anyways, neither it at literal 0% when it shuts off either. Their are built in protections nowadays on modern smartphones for that.

"100%" and "0%" have everything to do with industry-standardized voltages. Lithium battery chemistry can do anywhere from 0-4.20+ volts. Battery life is always degrading at any voltage, but the industry has determined that below 3.0V and above 4.20V the life degrades unacceptably.

300-500 cycles at 4.20V is acceptable degradation according to the industry, which is why that's set as "100%."

But if you want your battery to have three times the charge cycles as well as maximize its life in storage, the battery chemistry has the most endurance at 3.80V, what the industry says is "80%."

Keeping your battery plugged in and thus permanently at 4.20V is unquestionable worse than if it was kept plugged in but allowed to only get to 3.80V. For customers who are more tech-minded, software should be provided that normally only charges the battery to 3.80V, but allows the battery to be charged to 4.20V by the user if the user expects to disconnect the device from the mains and needs that extra capacity temporarily for in-field use.

 

[Red Squirrel]

I think that's what they should do, default to "80%" but call it 100%. Then add an option where you can tell it to charge to 4.20, and it would just start to go to 120%. This could be used on a per need basis. and just be a simple option you press when the phone is plugged in.

Of course these companies expect people to change their phones every 3 years, so doubt they'd ever do anything like this. If the battery can last for 2-3 years that's good enough for them.

 

[fuzzybabybunny]

FYI, I just checked my battery monitoring app. 100% is actually 4.35V, which is even worse than 4.20V.

According to the link in the OP, 4.35V would make the battery only have 150-250 cycles, compared to 300-500 cycles for 4.20V.

 

[Staples]

I always use a 1amp charger with an iPhone and iPad. They are both 4.5 years old and the battery seems fine. Rule of thumb is never to drain them to 0 and use a slow charge. Those two will prolong their lives. You also don't want to overcharge them but most devices now shut off the charge cycle so you don't need to worry about that.

 

[Yakk]

Quick charging for Samsung can reach 4.35v and it lowers as the charge progresses. Turning it off probably lowers the voltage all the time. Having the option for a 30min. Quickcharge to 50% does come in handy on occasion though at the airport & such.

 

[clamum]

Hmmm. I wonder if maybe my phone is actually holding less of a charge and it's not just in my head. I have an S7 Edge that I got in approx. June of 2016 and for several months I've noticed the battery drains faster than it used to (for example I now have to keep Wi-Fi off to get the phone through the day on a full charge when I used to just it on). I put it on my wireless fast charger at night and take it off in the morning when I go to work.

I've done a couple small Android apps, maybe I should look into doing one that limits charging to 80%. It's kinda hard to believe there isn't one out there that does this though.

 

[nakedfrog]

FYI, I just checked my battery monitoring app. 100% is actually 4.35V, which is even worse than 4.20V.

According to the link in the OP, 4.35V would make the battery only have 150-250 cycles, compared to 300-500 cycles for 4.20V.

Assuming you're getting an accurate reading from the app...

 

[drinkmorejava]

You guys are missing the forest for the trees. By not charging to 100% you get better battery life, but the other half of the report talks about how discharging to levels greater than 0% also gives better life. Putting this all together you get:

The black line here shows that you get 1000 cycles to 90% life under a normal scenario (not discharging all the way as done when 300-500 cycles are quoted), which is very reasonable for a device that most people only use for two years.

 

[lxskllr]

...which is very reasonable for a device that most people only use for two years.

My "new" phone is going on three years old(lg g3). My last phone(S5) I had for 2.5 years before it ran into a series of sudden impact events that broke the screen :whistles: If not for that, I'd still be using it.

Perhaps people should be less wasteful, and insist on a removeable battery since that's the sensible position. I wonder how many people that get a shiny new slab every year or two bitch about /corporations/ polluting and wasting resources?

 

[KMFJD]

I got feed up with my S4's battery life and bought an aftermarket battery that almost doubles the battery life, needed a new back plate but it came with one, best $25 i ever spent on a phone.

 

[clamum]

While my S8 Plus has an awesome battery, way better than my S7 Edge after just a year, I'm still interested in this 80% charge thing.

I've done some looking and I don't think it's possible for an app to shut off charging at a specified level; I looked at the Android battery API and the charging state is read only. There was some other thread I read, maybe it was on Stack Overflow, and people had the same conclusion.

However, if you picked up a smart outlet and used the IFTTT Android app (make sure the outlet is IFTTT compatible, not all are), I think you could shut off the power to the outlet that your charger is plugged into at the specified battery level. I'm not sure at this point but it might take another app in addition to IFTTT to detect the charge level; if so I could write it easily.

I didn't even realize there was such a thing as smart outlets until I was looking into this but I might actually pick one or two up cause they look kinda neat and I have an Amazon Echo which works with a lot of these smart outlets too. Cool stuff!

 

[JTsyo]

If you charge to 80% instead of 100%, that also means to get 400% charge, you would have a charge it 1 extra time at 80%. So that's a 25% increase in charges. In real life it wouldn't matter as much since you won't be dropping to zero much.