You guys joke and all, but fast charge induces bigger heat and then translates in more harm for the batteries (which will affect more in hot places).

If we want to close this discussion forever I think all the anxiety that comes from this subject at all is due to the fact we can't easily replace the batteries, if we could (with the normal-ish battery sizes we have today), I don't think this test would be even worth doing.

https://www.wired.com/story/how-to-improve-battery-life-tips-myths-smartphones/

Iirc the reason Samsung phones were exploding a few years back is because they fucked up the settings for battery management.

Yes, but that 100% is not really that. It has been programmed to display that percentage, when i reality its 80%.

I bet thats wrong, but I know ….

There've been usage changes

• iPhone has “Optimized Charging” where it predicts usage and tries to keep about 80% charge until it expects you to use it
• iPhone has “Adaptive Performance “. Maybe not charging but tries to gradually ramp to “low power mode” to be gentler on the battery
• all phones likely have refined charging curves to match battery technology

That works if you have a correct sleep schedule… this feature only enabled like 20 times in my life, and half the time it disabled itself because I used my phone during the night

Well not charging to 100% all the time will improve your battery life, and if you keep your devices a long time and have a usage pattern that allows charging it less like I do (I leave mine on a wireless charge pad at work), then it makes sense to make some adjustments to that particular setting.

But the point of this video is whether the things you have control over make a significant difference.

I'm not saying your opinion is wrong or that you have to watch the video or anything like that, but videos like this are made so that you can see the testing procedure and judge it's validity without just having to assume they did their job right. I wouldn't trust someone just saying "yup, tried it out, doesn't really matter 👍🏽"

I'm sorry that you're allergic to information.

And probably not as intentional as most people think it is vs just laziness and maybe a lack of planning.

The planned obsolescence is most likely a deliberate trade off rather than actual planned obsolescence.

If fast charging did do significant damage to battery life and this was known at the time of implementation, the decision would have been "users want fast charging phones" Vs "users want devices that last a long time".
In this instance, the convenience of fast charging absolutely would have won.

"Users want a clear and easy to use device" Vs "users want a robust device". Which is why we all have glass screens, and the glass technology had to catch up to further expectations.

"Users want easy wireless connectivity" Vs "users want fast and reliable network speeds". WiFi wins, and has to catch up to further expectations.

It is, if you are just dealing with bare batteries without any kind of protection, but if you are dealing with cellphones/modern smart devices, not so much

Thanks, I’ll watch this

In a previous job I once evaluated some returned product that wasn't having the best battery life or wasn't working right. It was specialized expensive equipment that used regular alkaline batteries.

TL;DR: ordinary batteries can have negative voltage if you don't give a fuck and just mix your old and new ones in a drawer before you put them into your high-cost life-saving equipment.

Lithium-* batteries don't actually have any specific useful numbers. It's something like this (the actual numbers are pulled out of my ass and depends on battery time and test parameters and even then I'm simplifying):

• At 0 volts, the battery is dead.

• At 1 volts, the battery is practically dead.

• Discharging to 2 volts kills it after around 100 times.

• Discharging to 3 volts kills it after around 10 000 times

• Discharging to 3.5 volts kills it after 100 000 times

• Charging to 4 volts kills it after 100 000 times

• Charging to 4.2 volts kills it after 10 000 times

• Charging to 4.3 volt kills it after 1000 times

• Charging to 4.4 volts kills it after 100 times

• Charging to 4.5 has s significant chance of it catching fire

Now choose how many charge cycles you want it to survive, and you know which voltage to consider 0% and which to consider 100%. The bigger difference, the bigger capacity with the same battery.

This is why a phone with 0% battery can tell you that it's out of battery.

You can also adjust what "killed" means. Is it when battery capacity is reduced to 80%? 50%?

I have to repeat - the numbers are not accurate, and this is strongly simplified.

It's just an illustration of what 0% and 100% means it's just where you are on the useful range, according to the manufacturers definition of useful.

The battery has a charge curve. What does the most wear or damage to the battery is the ends of the curve - either deep discharging the battery or charging it up fully to the point where it cannot take any more charge. It's up to the manufacturer where they want to put 0% and 100% on the curve - to protect and extend the life of the battery most manufacturers don't put 0% and 100% at the extreme ends of the curve.

A cell's voltage will change with how much energy it stores, but if you keep applying current to force more charge to move you can cause voltages to be quite far outside of the proper range. However you don't want to do this as at minimum you are damaging the materials in the cell, or worse, cause a significant safety hazard where the cell could catch on fire.

You can look at the Discharge Curve of a cell which compares voltage vs capacity, as a rule of thumb, essentially the steeper the curve changes, the more damage you are doing to the cell by operating in the range.

Best source I can find: https://eugen-barilyuk.medium.com/how-i-realized-android-battery-percentage-wasnt-serious-enough-0310e484d874

3.7v is 0%, 4.2v is 100%. But a lithium battery can go higher and lower, it's just that doing that can harm the battery, perhaps spectacularly. OEMs just narrow the voltage range to extend life. When you set a charge limit, it narrows that range further.