Is it safe to use this 60W PD charged for a late 2016 MacBook Pro 13"?

The bundle charger is 61W. This USB Type-C charger comes with Power Delivery 60W:

Can I use it as an alternative for charing my MacBook Pro 13" (late 2016)?

Solution 1:

Generally speaking, using a charger with a lower watage rating than the charger that came with the device will just mean that the device will take a longer time to charge. As long as the charger delivers the correct voltage (which is set by the USB specifications) it will not damage the device. Thus, if you trust that the charger properly follows the specifications laid out by the USB industry group, it should not pose a danger, but could take longer than a "proper" charger.

Using a charger with a higher watage rating should also work, but has the potential danger of allowing the device to draw more power than is safe for the device. In this case you would need to trust that the device maker has followed good design process and limits the power that it draws rather than just taking the maximum that the charger can push out.

I trust Apple not to allow their devices to draw more power than they can handle, and thus often hook up low power MacBookAir devices to high power MacBookPro chargers.

Solution 2:

I own a Macbook Pro 13" (2016) and the Anker charger in the picture. I'm using it right now as a power source. So it works, without setting anything on fire (so far). However, there's an important caveat: The Anker charger DOES NOT deliver the 60 watts the Macbook Pro wants over the USB-C port.

• The Apple power source delivers a max 61 watts (20.3v @ 3A). Though according to this test at GTrusted, when charging the macbook pro is actually drawing 60 watts (specifically: 20 volts @ 3 amps). I know, it's just a watt, but rating the charger at the odd 61 watt while it's only delivering 60, seems like a silly way to make the official Apple charger appear proprietary. Whatever.
• The Anker charger delivers a max 45 watts (15v @ 3A). So it likely takes a little longer to get a full charge, but I haven't timed it or noticed. Here is the gruesome detail. EDIT: I did some testing, and it looks like it's only getting 30 watts (15v @ 2A).

This is important, because it potentially means travelling with just one universal charger for a macbook, iphone, ipad, wireless headphones, etc. -- if you're willing to take a hit on charge time for the macbook.

Here's what I don't know: does the delivery of 45 watts, instead of the optimal 60, have any negative impact on the computer. Specifically, does it a) harm the battery life over time, or b) risk damaging the computer, battery or power source when using the computer under heavy loads (screen at 100%, heavy load on CPU, etc)?

Bottom-line:

1. It charges a macbook pro 13" (2016), but...
2. ... Not as fast as is possible with the Apple-supplied charger
3. It's not clear to me whether it could cause damage over the longer term.

It would be great to see Anker or someone make a similar product delivering 60 watts with 20 volts @ 3 amps (Apple can keep it's extra watt) through the USB-C port. That would solve everything.