iPhone no longer charges from non-Apple accessories if locked

(mpainesyd) #1

Hi Adam & Josh

I just sent this feedback to Apple:

Yesterday I updated my iPhone to 11.4.1. I plugged it into my Belkin dock as usual in the evening. In the morning it was only at 30% charge so I thought I hadn’t docked it correctly. However this evening when I docked it I noticed the message “Unlock iPhone to use accessory” and the phone was not charging. It only charged after I unlocked it. This unannounced and pointless change is a serious personal safety issue as people like me will assume their phone is charged for the day. Please reverse the change or at least make it a selectable option.

USB Restricted Mode Can Block iOS Device Charging
(Curtis Wilcox) #2

It was announced and is not pointless. It’s USB Restricted Mode and it was discussed as an upcoming iOS 12 feature but was delivered early in the 11.4.1 update. TidBITS linked to an article about USB Restricted Mode in The Verge. Its primary purpose is to protect against passcode cracking tools. It can be turned off.

Using USB accessories with iOS 11.4.1 and later - Apple Support

(David Rostenne) #3

Seriously? Apple decided not to allow charging over USB accessories as well as locking out all the other functionality? That makes no sense to me… unless there’s some odd configuration in the controller chip that can only do all or nothing.



(Doug Miller) #4

It does allow charging, but the Belkin accessory must be trying to access data over USB that a normal charging cable/charger does not.

(Adam Engst) #5

Sounds like this would be a good topic for an article, @jcenters.

(Seth Anderson) #6

Anecdotally, my iPhone X still charges when I plug it into my car’s USB port (while it plays music).

I also have a Samsung wireless charger thingie, it still works.

The Belkin must be doing something different if it no longer works as expected.


and for the record, I whole-heartedly support Apple’s decision here. This was a potential security breach vector that iOS is addressing.

(David Ross) #7

Or maybe the cable. If off off brand it may not have a “real” lightning security token.

(mpainesyd) #8

Thanks for the link Curtis - I did try searching the Apple Support webpages for this advice without success. So my apologies to Apple. I have now switched on USB Accessories support (but will take care using unknown accessories as usual).

The odd thing is that Belkin Dock is just supposed to a charging station - it has no other function - and it was apparently Apple-certified when I bought it many years ago. I have found it very handy for video conferencing since the iPhone is upright and still charging.

(Curtis Wilcox) #10

At work I have a Twelve South’s HiRise 2 Deluxe that’s nothing but a metal stand with their Lightning cable threaded though it and I’ve gotten the message on it as well. I notice the message and don’t mind pressing the TouchID to unlock it.

At home I have an old Apple dock with a 30-pin to Lightning adapter, I don’t recall if I’ve seen it there; since that’s where it charges overnight, missing the message would be a bigger problem.

Edit: Unsurprisingly, the home dock + adapter can trigger the message as well.

(Alan Forkosh) #11

I’ve seen the message when I connect to a Lightning Cable attached to a computer or my iHome Clock Radio but not when connected directly to a ‘dumb’ charger (Apple or Anker).

(Josh Centers) #12

I’ve written an article that explains what’s going on https://tidbits.com/2018/08/06/usb-restricted-mode-can-block-ios-device-charging/

(Phil Seymour) #13

It is a security measure. Being asked to open my iPhone before backing up, uploading, downloading and sometimes charging isn’t that big of a deal when you think about it from the security issue. I don’t think it is entirely a device to force us all to buy Apple branded accessories. I admit that I resist some of the wrong headed, lazy programming that has plagued recent developments by reinstalling older versions of Apps that have taken a turn for the worse and I use a mid 2012 Macbook Pro and a SE iPhone 6 because they are more useful than the newer stuff, but the charging thing makes us more secure.