iPhone X Fast charging iPhone X

[andreasts88]

hello ,

I don’t know if this is the right place for this post, but I would like to ask you if the fast charging is safe for battery health.
I bought an 18W APPLE adapter and I was wondering if could reduce battery capacity compared with the 5W included adapter .

According to Apple the only difference is the time of charging and battery not affected.

 

[estabya]

I’ve wondered this as well. I have a hard time believing that the faster charging and extra heat don’t cause some sort of accelerated degradation.

 

[now i see it]

All lithium batteries can be charged at a rate below about 0.5C without significant degradation. 0.5C equals 1/2 of the battery capacity in mAh. If you have a 2800 mAh battery, a 0.5C charge rate is 1400 mA.

But for most people, that's mumbo jumbo. The easiest way to tell if your charge current is degrading the battery faster than you want (trading off the convenience of a fast charge at the expense of decreasing battery longetivity) is to just feel the phone. If it's getting hot, the charge is degrading the battery faster than if you used a smaller 5W charger.

When the phone is discharged below 50%, plug into the fast charger and feel it's temperature after 15 minutes.
Then next time it's below 50%, charge it with the 5 watt charger and feel it's temperature after 15 minutes.

If the fast charger significantly heats up the iPhone, its degrading the battery's lifespan regardless of what Apple says.

If you're the type that replaces an iPhone every 2 years, a fast charger won't make a significant difference in battery degradation. But if you want to keep it 3-4 years, then yes, always fast charging will take it's toll.

Remember though that fast charging only occurs when the battery is discharged somewhere below 50- 60% or so. Once the charge level hits 80% or so, it doesn't charge significantly faster than the 5 watt charger.

 

[AppleHaterLover]

I can’t answer your question but here’s some anecdotal experience.

iPhone XR. Purchased mid-Dec 2018
Fast-charged religiously at least once a day using my 61W MBP charger.

When not using that charger, I charge it in my VW (USB-A fast charging, I guess 12W?) and over USB-C on my Dell Latitude whatever corporate laptop and 2017 MBP. I’m guessing 12W for both?

Must be around 250 cycles at this point. Battery is at 98%, and if I didn’t have this information I’d never know since it is as good as new.

If there’s a degradation penalty, I guess that might be a fair price? The 5W charger is inadequate and insufficient to charge the current iPhones.