Or as this hasn’t been widely reported something else is going on…

Try different chargers, there’s a lot of defective hardware out there. Also it’s at 80%, but there’s a setting on iPhones and possibly iPads etc that avoids charging to 100% to preserve long term battery life if you’re going to leave the device plugged in long term.

I don’t know about iPads, but my iPhone shows a message when the delayed charge thing is active. I think it’s even one of those always on notifications you can’t swipe away.

Delayed charge (waiting to charge fully or charging the last ~20% slowly to just-in-time for your alarm) is a different setting, though I don't recall the name for the "Only charge to 80%" one

"battery saver"

Can you tell an iPhone to only charge to 80%? I only have the “optimized charging” option, which is the delayed one.

Yes.

> To change your charging option with iPhone 15 models and later, go to Settings > Battery > Charging and choose an option. You can choose a charge limit between 80 percent and 100 percent in 5 percent increments.

https://support.apple.com/en-us/108055

OK, that explains it, mine is an older model. Wonder why this setting doesn't apply to them...

Probably a combination of the devices being old enough and the battery not being large enough that a lot of people would not find 80% of the already-degraded capacity of their device reasonable, and not wanting to have to explain to customers why their friend’s phone allows it and theirs doesn’t if they both have the same model.

Yeah, USB-C is a bit of a nightmare when it comes to knowing what a given cable can actually do.

Well, all cables can charge at least. It is not a usb-c problem but an apple and /or charger manufacturer one.

My bet would be sth about the voltage the charger provides.

Its not the setting. It charges fine to 100% with the same wall-wart and a tiny usb-a to usb-c adapter then the apple cable. But not happy with my regular usb-a to usb-c cable (that works fine with everything else). Or any of the other cables in my house. A message pops up about non-compatible cable. I suspect the ipad has been designed to be deliberately fussy. I'm in europe, if that makes any difference.

I charge my iPad Mini with a variety of chargers, all the way to 100%. None of my cables are from Apple, only some of my (USB-C) chargers are not from Apple.

Are you sure it is because of the cable? By default Apple devices only charge to 80% when you plug them in and then do the final 20 later around when they anticipate you are going to unplug it.

Its not that. It shows a message about 'non compatible cable'. And when I use the apple cable it quite happily charges to 100% with no quibbles. And the non apple cable is a good quality one that works fine with everything else. I suspect the ipad has been designed to be deliberately fussy.

Our household has a number of iPads and never had an issue with any non-Apple usb-c cable I’ve used to charge them with, mostly Anker branded but one or two AmazonBasics or Cable Matters brand. I’ve never seen an incompatible cable warning, my suspicion is it’s a cable that doesn’t have the right signaling to go above 5V, so it’s stuck charging at 5V and the iPad prefers to charge at 9v or 12v.

Right maybe, but why make the ipad so fussy? Why cant it chill at 5v? I am suspicious of the design decisions made here

It’s likely that your wall-wart doesn’t provide enough watts to fully charge your iPad mini, and/or that there’s some reason the USB-A side of that cable isn’t adequate for what the iPad mini needs.

If you want to test, consider trying with a non-Apple wall-wart for which the rated wattage is equal to or greater than the one which Apple provides with your iPad mini and which uses a USB-C connection rather than a USB-A one. If it comes with a USB-C to USB-C cable, use that, otherwise get one that supports USB-C PD and enough watts to match the iPad mini’s needs.

That can't be the explanation. Batteries use fewer watts as they get close to full.

That's not fully true, and even if it's partially true in some cases (this depends on the chemistry of the battery): volts and watts aren't the same thing. You can be fully capable of supplying [email protected] and not capable of supplying 12v@1A which are the same number of watts.

Battery tech is a horrible black hole that is not very fun to dig into, chargers are a little bit more transparent: with markings for various voltages and amperages printed on the device.

iPad batteries output 3.7v if I'm not mistaken, but I'm unsure what they charge with.

  > iPad batteries output 3.7v if I'm not mistaken, but I'm unsure what they charge with.

For those not familiar with the tech, the term "3.7v battery" means that it is about 4.2 volts when full. Black hole indeed.

I would expect much bigger issues and failure to charge at all if there's not a reasonable voltage on the USB line.

A 3.7V nominal li-ion battery would peak at about 4.5V while charging. A bit high, but a well designed circuit should be able to do that off 5V. Besides, 75% is far short of where the voltage starts to spike.

>volts and watts aren't the same thing. You can be fully capable of supplying [email protected] and not capable of supplying 12v@1A which are the same number of watts.

For the layman, the equation is Volts x Amperes = Watts.

Where if we use the common water examples: Voltage is electric charge ("water pressure" or "volume of water"), Amperage is electric current ("water flow rate"), and Wattage is electrical energy ("amount of water transferred").

2V x 6A, 4V x 3A, 1V x 12A, 12V x 1A and similar are all 12W but they are obviously very different in nature.

More … peak voltage or something like that?

Sounds great. Very good charger for battery life.

Agree. I bought a "Chargie" just to get this feature, and it doesn't work with my wireless chargers worth a darn. I would pay at least $40 x 5 units for chargers that reliably stop at 75% with no software required.

What? Isn't that a function of the device? The only alternative would be to start discharging at 75%, and I don't want my batteries to constantly cycle while plugged in. I leave them plugged in so they'll run off of wall power.

> The only alternative would be to start discharging at 75%

Not necessarily, Chargie lets you configure minimum charge, minimum charge for a cycle, time to charge, etc.

In practice, what it looks like for my devices:

1. I plug in my phone when I go to bed. 2. Phone charges to 40% (if it's not already >40%) and stops charging. 3. At 5am or so, the phone is still at ~38%, it then charges to 80% and stops. 4. I get up and my phone is still at ~78% charge.

For devices with more software capabilities than phones (e.g. macOS) you can use software (e.g. Al Dente) that will cap the charge level and run off wall power. In practice this means that if I plug my laptop in at 90% charge, it will take weeks to drop to 80% since it's running off wall power, and unless I'm doing particularly high power-draw things the drop to 80% comes down to the battery's self-discharge rate.

I have some Chargie units, but found them finicky enough with the bluetooth connection that I've abandoned them for devices' built-in 80% charge limit, even if the exact charging pattern isn't quite what I'd like.

You're sure it's not the "optimized battery charging" feature?

https://support.apple.com/en-us/108055

I don’t believe it’s the cable as much as the charging brick that is causing that. I have that issue with a MacBook Pro, using the Apple provided cable plugged into a usb-c port on my power strip. If I use the power brick, it charges fine.

I can't beleive I'm seeing this on HN. This is really a fuckup of the industey if they're even confusing technical people.

A lot of phones only charge to 80% to wave battery life. You can change this setting. Spread the world.

I wonder how much they pay in tech support because of this one thing.

When I use the apple cable it charges to 100% with no quibbles

> This is really a fuckup of the industey if they're even confusing technical people.

Honestly, we're not that great.

I have a number of quality, 3rd party USB PD rated cables which work without issue on iPhone 16, iPad Mini 6g, MacBook Pro. Both with and without 1st party chargers. Admittedly the options for consumers in the USB-C space are a confusing mess, but I’ve never had problems with stuff from brands like Ugreen or Anker where USB-PD support is specifically advertised.

I’ve got a 6th gen iPad Mini, it charges to 100% using an Anker charger and no-name USB A-C cable