stpfun t1_jdwwug5 wrote on March 27, 2023 at 8:03 PM

Reply to comment by ONE_BIG_LOAD in Phone keeps popping up with this error, but it's not wet or ever has been? by very_cozy

That's rad! I'm sure it can use that full 65W when the battery is low. Though I'm pretty sure it can't use the full 65W of charging power the entire time it's charging. LiPo battery chemistry just doesn't allow it.

It's also easy to show this with math. According to the internet the OnePlus 8t has a 17.02 watt-hour battery. As in it stores enough energy to output 17.02 watts for 1 hour. (though it probably can't discharge that fast in practice). If a 17Wh battery charged at 65W the whole time it would take 17Wh / 65W = 15.69 minutes to charge! But because it takes 35 minutes, we know it must charge at 17 Wh / 35 minutes = 29.14 watts on average. Which is still craazzy fast. The latest iPhones, which can charge at 20W peak, but have an average more in the range of 12W.

I got into this stuff just by playing around with a USB-C power meter like this one. With that plugged into my charging cable I can finally actually see how many watts my devices are pulling at any given moment.

ONE_BIG_LOAD t1_jdwxe07 wrote on March 27, 2023 at 8:06 PM

Woah that's cool stuff. I have an app on my phone that tells my current charging stats so I'll let my phone drop down to 5% or so today and see how many watts it's pulling.

At lower battery it really is fast I can leave it on for 5-10 minutes and be back upto 50% after that it starts to charge a bit slower.

BTW I've never owned an iPhone but I like to stay educated... How long do the latest iPhones take to charge? 10W sounds like nothing but I also believe iPhones have significantly smaller batteries/better optimization than Androids.

stpfun t1_je13dpj wrote on March 28, 2023 at 5:29 PM

in my experience iPhones take ~90 minutes to fully charge, but similarly to your experience they charge up to the first 50% much faster with a faster charger, though more like 30 minutes instead of 5-10. (I'm jealous!)

And you're right that it seems like they have smaller batteries! Like my non-large iPhone 14 pro has a 12.38Wh battery but it lasts all day easily. Never thought about it before but this must mean that Apple's chips/software just pull less energy. (also I was wrong before, if a 12.38Wh battery takes 90 minutes to fully charge then it's average charging rate is only 8W, even lower than the 10W-12W I guessed!)