Using USB A Male to USB C Female adapter for charging iPad Pro

First, understand that many Apple devices support USB PD (Power Delivery) Fast Charging - but do not support other proprietary charging standards such as QC (Quick Charge).

A Power Adapter or other USB power source that presents a USB Type-A output should provide a standard 5V USB output. When used with 5V charging sources, iPad will limit its maximum charging rate to ~12W (i.e., 2.4A @5V). When used with USB-C Power Adapters or PowerBanks that support USB PD, the iPad’s maximum charging rate is ~20W - the power profile being actively negotiated by the power source and connected device.

When charging your iPad, you should use a certified USB-C cable. The USB-C standard does not certify simple plug adapters - as these can introduce incorrect wiring that can seriously damage connected devices.

Consider that your iPad Pro is an expensive investment - and will be very costly to repair if damaged by incorrect connection. If damaged by an uncertified third-party cable, plug adapter or power source, your iPad warranty may not cover the cost of repair. As such, you would be well advised to only use OEM, or at the very least, properly certified power sources and cables. Cheap alternatives are false economy.

There's no specific restriction of 5W for USB-A to USB-C just because there's no USB-PD. I've got an older Mac with USB-A ports. I plug in a USB-C/USB-C cable with a USB-A male to USB-C female adapter with my iPad mini 6 and System Report says that it can provide 2100 mA (10.5W). I get the same if I just use a USB-A to USB-C cable.

There are a lot of USB-A power adapters that do output 15W at 5V through a single port. So having that available isn't terribly unusual.

FinlayC14 wrote:

I understand that, however rather than about the usage of adapters and cables and the certification, I’m more interested in whether the iPad charging at 15W is safe for the battery because with just using a USB A to USB C cable, it is only 5W. How come when using this solution of a USB A Male to USB C Female adapter connected along with USB C to USB C cable into the iPad, it can charge at 15W? It isn’t using PD so I’m confused how it’s reaching that potential. I’m just wondering whether it’s ok charging at that wattage because I thought it’s either 5W without PD, and 18W with, but this isn’t using PD.

It doesn't sound like it's a problem. USB-A has been capable of more than 5W for some time. I don't see why it couldn't push more into a USB-C device since it's really just 5V at 2+ amps.

When charging from a standard 5V USB bus, the iPad will limit charging to ~12W (2.4A @5V). A USB Power Supply rated at 15W will do no harm to your iPad - as the iPad will only draw the maximum power that it requires, subject to its maximum charging rate.

LotusPilot wrote:

When charging your iPad, you should use a certified USB-C cable. The USB-C standard does not certify simple plug adapters - as these can introduce incorrect wiring that can seriously damage connected devices.

Not sure about that. It's really the wild west out there since it's not like the MFi certification process that Apple has. They have a list of licensees, but there's a lot out there that isn't on the list. My preferred USB-A to USB-C cable is one that was packaged with a (now dead) Amazon Fire HD 8. And one can use Apple's USB-C cables. There are a lot of companies selling USB-C cables that don't have USB certification including Belkin, Amazon, and Monoprice.

I'm trying to even figure out what USB-C cables I have that even are USB certified. About all I could find is that I've got a USB micro-B drive to USB-C cable fro UGREEN. I'm guessing a lot of cables might be certified, but they might be packaged as an accessory without any clear indication of who made it.

BTW - Apple doesn't have a currently certified USB-C cable. Not even any former certification. I mentioned UGREEN, which is listed as a company in the USB products database, but where I see no current products listed.

https://www.usb.org/products

To recap, many USB testers and power meters have questionable calibration.

Returning to your original question - and my initial response, USB-C Certification does not extend to simple plug-adapters. Use these entirely at your own risk.

Cutting corners on USB connections is false economy. Any potential cost saving pales into insignificance when compared to the cost of repair of an expensive electronic device - such as your iPad. Damage to your iPad caused non-certified interconnects will not be covered by warranty; any warranty provided with the cable/plug-adapter, if any, will not cover consequential damage.

It’s your choice - and entirely your risk to take. Caveat Emptor (l.)

Others may advocate use of cheap/uncertified products of potentially dubious origin and specification. Perhaps they can afford the repair bill if all goes wrong - or perhaps they have a greater risk appetite. Believe me when I say that those that play with fire will eventually be burned by it - and when they do encounter the consequences, their attitude to risk invariably changes 🙂

Have you looked at the configuration of the contacts in your particular USB-A to USB-C cables and/or tried different ones? I have a variety of them, and they can be different. Some even have unbalanced layouts where one side has more contacts than the other, but I don’t question it too much when it works. Some have contacts around the center. And some have the full 24 contacts.

This mentions this company making a power only USB-C connector that only supports 5V at 1 A.

https://www.cuidevices.com/blog/an-introduction-to-power-only-usb-type-c-connectors

And how are you determining the charging rate of your iPad? Many commonly available USB testers, where used, have questionable calibration.

USB certification is still somewhat rare. Belkin, Salcomp, Artesyn, Flextronics, Mophie, Monoprice, and many others have chosen to not go for it. Not even Apple.