How the USB-C Port on the New MacBook Helps the Battery Life

Image credit: Apple.

There have been vociferous complaints about Apple's new MacBook thanks to its single USB-C port. However, it turns out that having only one port helps the MacBook in a very important way. How's that? Allow me to explain.


When one is on the go, generally, the only thing that gets connected to a modern notebook computer is a power adapter in the evening. This is a good thing as we'll see below.

However, when, say, a MacBook Air/Pro sits on the user's desk in the office or at home, all kinds of things get connected. Time Machine drives, USB Flash drives, printers, microphones and so on. With that tempting MagSafe power connector just sitting there on the desk and a separate MacSafe port on he Mac, it's all too easy to think, why don't I just connect it to power and leave it while I work?

That turns out to be a bad idea. Here's why.

Back on February 18, 2010, our Dave Hamilton wrote a How-To article, "Mac Laptop Battery Life Questionnaire," on how to ensure the longevity of the battery in your MacBook (or any laptop). In that article, there were two things found to hold true.

  • Keeping your battery on charge most of the time seems to result in less than 50 percent of original capacity after about one year (even if you cycle it regularly)
  • Beating the heck out of your battery (i.e. half-charging, killing, half-draining, charging, and simply being erratic with it) seems to result in maintaining or even increasing battery capacity over many years.

The result of this is that if you're working at home or in the office with a MacBook and its single USB-C port, you may well have something plugged into it with the USB-C to USB 3.1 Gen 1 adapter. As a result, you're hard-pressed to keep a power adapter plugged in continuously.

In turn, when done working, it's a natural thing to then plug in the power adapter and retire the MacBook for the evening while it charges. This is exactly how we use our iPads. This design-enforced psychology of use turns out to be exactly what's good to prolong the life of the internal battery.

Image credit: Apple.

Hidden Variables

As so often happens, when Apple makes a fundamental change in the design of a product, we judge it based on past experience, not months of use. The evaluation of a new product is always subject to short-sightedness. As Phil Schiller said in the WWDC Mezzanine interview with John Gruber (1:01:20):

"I don't remember any great product we've made where people haven't panned it in the press in the beginning.... I don't know what a successful product is if it doesn't start out with people saying, 'I don't get it and I don't like it.'"

Part of that reason is that Apple engineers have thought through a problem and its solution, and we don't realize the elegance of the solution until we've used the product for some time.

Now, of course, that's not all there is to the MacBook story. The single USB-C port also forces us to think in different, wireless ways. See, for example, "How My New MacBook Speaks to Me." Also, USB-C Docks are coming in order to satisfy the needs of many users. And no doubt, many will fall into the old habit of continuously powering the battery—to its detriment.

In the final analysis, the battery longevity issue here is just a by-product of a device that works so well wirelessly. Perhaps that's why I've heard it said so often that the MacBook is the actual "iPad Pro." The best ideas from the iPads, also with just a Lightning port and audio port, can and should be implemented in a modern MacBook.

If customers like this MacBook design philosophy, they'll buy a lot of them.