Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Other A battery scientist's view

decafjava

decafjava

macrumors 603
Original poster
Feb 7, 2011
5,554
8,076
Geneva
Some science for you all on the throttling issue.

https://www.macobserver.com/news/battery-scientists-joins-debate-iphone-throttling/

ZedEffective noted that what battery engineers view to be a healthy battery is different than what your average, everyday consumer thinks is normal. When a lithium-ion battery’s capacity falls to around 70%-80%, that’s actually considered the battery’s end of life (EOL). [Source 1, 2]


These batteries work by moving lithium ions between graphite and another material. Over time the materials age and become damaged. During this process, it’s normal for side effects to occur. The main causes of “cell death” include:

  • Repeated cycling damages and cracks the graphite anode, lowering the amount of ions able to be intercalated into it
  • Lithium metal plates on the anode and can pose thermal risk, also lowers total Li-ions available for cycling
  • Passivation layers increase cell resistance past a practically useable point, and the cell cannot draw peak current
The last effect is the biggest reason why your iPhone shuts down when it has 50% battery left. Batteries are active chemical systems and can only perform at peak capacity for a limited number of times before they start to degrade.

From this perspective, Apple’s throttling of the battery is an attempt to minimize the number of these side effects and shutdowns. So to a battery scientist, this is perfectly reasonable.
Click to expand...
 
  • Like
Reactions: Ulenspiegel, joshellis625, Jamalien and 3 others
I'm interested in what Android manufacturers do differently when for example my old Galaxy S4 still works perfectly fine with the original battery which is 5 years old now. While it would surely benefit from a new battery, it has not needed one for performance reasons.
 
  • Like
Reactions: macfacts, mi7chy, Beeplance and 3 others
kasakka said:
I'm interested in what Android manufacturers do differently when for example my old Galaxy S4 still works perfectly fine with the original battery which is 5 years old now. While it would surely benefit from a new battery, it has not needed one for performance reasons.
Click to expand...
yeah but no updates, unless you Root
 
You don’t have to be a battery scientist to know that when a battery is at 70-80% capacity then by definition it’s not at its end of life. By definition it’s at 70-80% capacity.

If that were normal then why don’t all devices containing a battery at 70-80% capacity die and just stop completely working?

You don’t have to be a scientist to answer that, anyone with some common sense knows a battery will continue working at 70-80% capacity and it by definition you cannot say that it has reached its end of life.

Lol a battery that has reached 70-80% is considered end of life - what a load of crap. That person should not be classified as a scientist, it’s just BS propaganda because apple have been caught red handed.
 
  • Like
Reactions: Mlrollin91, macfacts, Beeplance and 1 other person
Zigourney said:
You don’t have to be a battery scientist to know that when a battery is at 70-80% capacity then by definition it’s not at end it’s end of life. By definition it’s at 70-80% capacity.

If that were normal then why don’t all devices containing a battery at 70-80% capacity die and just stop completely stop working?

You don’t have to be a scientist to answer that, anyone with some common sense knows a battery will continue working at 70-80% capacity and it by definition you cannot say that it has reached its end of life.

Lol a battery that has reached 70-80% is considered end of life - what a load of crap. That person should not be classified as a scientist, it’s just BS propaganda because apple have been caught red handed.
Click to expand...
You’re wrong. Both Apple and Samsung offer a free warranty repair on batteries that fall below 80% capacity within a certain timeframe. I think it is 2 years for Apple, and it used to be 1 year for Samsung. End of life doesn’t mean it will not work, it means it isn’t as efficient.
 
tonybarnaby said:
You’re wrong. Both Apple and Samsung offer a free warranty repair on batteries that fall below 80% capacity within a certain timeframe. I think it is 2 years for Apple, and it used to be 1 year for Samsung. End of life doesn’t mean it will not work, it means it isn’t as efficient.
Click to expand...

What I’m I wrong about?
I didn’t say apple and Samsung don’t offer warranty repairs when a battery capacity falls below 80%.

There is a difference between something that is less efficient vs. Classyfying something that is end of life.
 
  • Like
Reactions: iSilas
Old batteries just don't hold a charge well. If they are saying the devices will become end of life, that means there may be a potential flaw in the design. That the iPhone will start to shut off. Performance will only eat up the battery more quickly under correct circumstances. This will lead to less battery life. That would prompt a person to seek a battery replacement or new device.

So, in my humble and not so scientific opinion, Apple may be hiding an engineering flaw.
 
  • Like
Reactions: iSilas
Zigourney said:
You don’t have to be a battery scientist to know that when a battery is at 70-80% capacity then by definition it’s not at its end of life. By definition it’s at 70-80% capacity.

If that were normal then why don’t all devices containing a battery at 70-80% capacity die and just stop completely working?

You don’t have to be a scientist to answer that, anyone with some common sense knows a battery will continue working at 70-80% capacity and it by definition you cannot say that it has reached its end of life.

Lol a battery that has reached 70-80% is considered end of life - what a load of crap. That person should not be classified as a scientist, it’s just BS propaganda because apple have been caught red handed.
Click to expand...

Lithium ion batteries last, on average, for about 500 charge cycles. If you've gone through 500 cycles and your battery is at 80% capacity, it's pretty much EOL. Yes, it still works, but even some swollen batteries still "work". The battery is much less efficient at providing power after several hundred cycles, hence the whole throttling thing.
 
Tubamajuba said:
Lithium ion batteries last, on average, for about 500 charge cycles. If you've gone through 500 cycles and your battery is at 80% capacity, it's pretty much EOL. Yes, it still works, but even some swollen batteries still "work". The battery is much less efficient at providing power after several hundred cycles, hence the whole throttling thing.
Click to expand...
EOL to me indicates that the battery can no longer be used at all. I do not go by Apple terms. I go by the actual usage. Sure I'll get less battery life but as long as my device doesn't shut off, I can always charge it. Keep a charging brick even.

So perhaps Apple knows that the iPhone may just shut off rather than just give decreased battery life?

I've owned a lot of devices outside of Apple even with a Note 3 battery that is 4 years old, my performance is just fine. It is not being throttled. However I have to charge it a lot more. I'll get a new one if this one swells or stops charging all together.

If Apple and other manufacturers are hiding an engineering flaw, this would make sense. Getting less battery life is expected as batteries age. So why the lack of transparency from Apple on throttle practices?
 
  • Like
Reactions: iSilas and Zigourney
Septembersrain said:
EOL to me indicates that the battery can no longer be used at all. I do not go by Apple terms. I go by the actual usage. Sure I'll get less battery life but as long as my device doesn't shut off, I can always charge it. Keep a charging brick even.

So perhaps Apple knows that the iPhone may just shut off rather than just give decreased battery life?

I've owned a lot of devices outside of Apple even with a Note 3 battery that is 4 years old, my performance is just fine. It is not being throttled. However I have to charge it a lot more. I'll get a new one if this one swells or stops charging all together.

If Apple and other manufacturers are hiding an engineering flaw, this would make sense. Getting less battery life is expected as batteries age. So why the lack of transparency from Apple on throttle practices?
Click to expand...
Indeed, I'd also like to know why newer iPhones draw enough power to need throttling after a certain point of battery degradation. As I alluded to above, I understand the reasoning behind Apple doing it but as you've alluded to, this doesn't seem to be a common course of action for devices with Li-ion batteries.

Ultimately, the big issue for me is the transparency part. You absolutely have to throttle CPUs? Fine, just let us know when our phones get to that point and also let us know that a new battery will fix the issue.
 
  • Like
Reactions: iSilas, motulist and Septembersrain
Tubamajuba said:
Indeed, I'd also like to know why newer iPhones draw enough power to need throttling after a certain point of battery degradation. As I alluded to above, I understand the reasoning behind Apple doing it but as you've alluded to, this doesn't seem to be a common course of action for devices with Li-ion batteries.

Ultimately, the big issue for me is the transparency part. You absolutely have to throttle CPUs? Fine, just let us know when our phones get to that point and also let us know that a new battery will fix the issue.
Click to expand...
I agree. Why not just a pop up telling us we are being throttled? If we know we are getting bad battery life, we can turn on battery saver ourselves to throttle the device.

So what are they hiding, really?

If the shut off issues on the 6s were an indication, it's a serious flaw.
 
  • Like
Reactions: Martyimac, iSilas and motulist
Altis said:
So why does Apple throttle at well above 80%? ;)

When Apple considers the battery "Healthy" and not in need of replacement, it's already being throttled.
Click to expand...

Do you have a source for that? I hadn't heard that they throttle while the battery is above 80%.
 
joeblow7777 said:
Do you have a source for that? I hadn't heard that they throttle while the battery is above 80%.
Click to expand...

I'm mobile right now but go look at the other threads, as well as the Reddit threads on it.

The highest I saw that involved throttling was 92%, but there were many in the 80s.
 
  • Like
Reactions: motulist
Tubamajuba said:
You absolutely have to throttle CPUs? Fine, just let us know when our phones get to that point and also let us know that a new battery will fix the issue.
Click to expand...

You think it’s fine for apple to throttle your CPU? As long as they let you know when your phone reaches that point?

Why is that fine? Why should it happen in the first place? Why is it ok for it to happen as long as you are notified that a new battery will resolve the issue?

Fact is, it shouldn’t be happening at all.
 
  • Like
Reactions: bopajuice and motulist
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back