In an article last year we show the devices Apple which supports charging between them and which adapters (power supplies) can be used on several idevice. About compatibility.
I looked like a iPhone can be loaded without problems by a direct connection to iPad or MacBook, a iPad Pro with USB-C can be charged with the adapter from MacBook or connected directly to it, and so on. More details about adapters Apple compatible found in the article: “We can use the charger MacBook Pro for fast loading a iPad or iPhone?".
Owners of iMac I know that its USB ports are not only for connecting auxiliary devices, but can be also used for charging various idevices. From one iMac, the user can upload a iPad, iPhone, a keyboard Magic Keyboard, a Magic Mouse or even one MacBook Pro / Air. everything is to use the right cable for charging.
Fortunately, even if lately the trend Apple was to eliminate from ports the new generations of devices, at iMac 2020 was still too generous. An iMac are four USB-A ports si two USB-C ports (Thunderbolt 3), along with a SDXC slot.
If you are the owner of an iMac and a MacBook Air or MacBook Pro, you should know that you can upload the latter from iMac, using the USB-C port (Thunderbolt 3). Sufficient energy will be transferred through this port from iMac for MacBook, for charging the battery within a time equivalent to charging the adapter. But there is a very important aspect to keep in mind.
I have seen many users who have tried to upload a MacBook Pro or Air from iMac, encountered a seemingly illogical error. Although the status indicating the battery level and status shows that there is a connection to the adapter, the battery does not charge. Power Source: Power Adapter / Battery is Not Charging.
Why not charge MacBook Pro or MacBook Air of the iMac and “Battery is Not Charging” status appears?
Most users who want to charge a battery MacBook Pro or MacBook Air from iMac, try this using the original charging cable, used at the plug adapter. This charging cable can only be used for charging from a direct power source to the outlet. It is not a Thunderbolt 3 cable capable of activating the USB-C charging port of iMac.
The two Thunderbolt 3 (USB-C) ports of iMac can be used to connect a monitor (DisplayPort), can be used for connections Thunderbolt with speeds up to 40Gb / s, USB 3.1 Gen 2 with speeds up to 10Gb / s, Thunderbolt 2, HDMI, DVI, VGA. (with adapters purchased separately) or as source for charging other devices-hate. The condition for these ports to act as a charger, is that the connection cable is also USB-C (Thunderbolt 3).
Although these cables all look like normal USB-C and they can be connected through the same ports, the differences between a classic USB-C cable and a Thunderbolt 3 cable they are very large. In addition to the large volume of data, the Thunderbolt 3 (USB-C) cable also supports a power transfer up to 100W and is recognized by devices Apple.
When you try to charge a battery MAcBook with a normal cable, you will most likely receive iMac notification: CANNOT USE THUNDERBOLT ACCESSORY - Connect accessory using a Thunderbolt capable cable.
Clear sign to be able to charge a battery MacBook Pro or MacBook Air of the iMac, you need to buy a Thunderbolt 3 (USB-C) cable. Cable that you can also use for data transfer.
You will find that the price of a Thunderbolt 3 cable (USB-C) is almost double the the price of the original cable loading came in the box MacBook. I'm talking about the original cables, Apple.Power Source: Power Adapter / Battery is Not Charging - MacBook Pro, MacBook Air [How To Fix]