As soon as Apple launched the 12-inch MacBook in early 2015 with a USB-C power port instead of MagSafe, it seemed to me the writing was on the wall. I predicted then that Apple would do the same for the MacBook Pro.

I was sad to see it go. It was a fantastic feature that has saved numerous MacBook machines from an untimely death as someone snagged their power cables.

But USB-C does, of course, offer some compensating benefits. The ability to choose to have the power cord on either side of my MacBook Pro has proven handy on a number of occasions. But an even bigger advantage is that we can finally have easy access to additional portable power through a USB-C battery pack …

Of course, a MacBook demands a lot more power than an iPhone or iPad, so it’s no use expecting to power it from any of the numerous low-capacity packs out there. But there are now high-capacity ones aimed specifically at powering laptops, so I decided to try two from well-known brands: Mophie and Anker.

I tested the Mophie Powerstation USB-C XXL and the Anker PowerCore+ 26800. Since neither name exactly trips off the tongue, I’m simply going to refer to them as the Mophie and the Anker from now on.

Capacity

Advantage: Anker

The Mophie has a capacity of 19,500mAh at 30W. That’s well above the typical 5-6000mAh capacity seen on powerpacks aimed at charging phones, but Anker leaves it for dust. As you would guess, the number in the name is the capacity, so you get a whopping 26,800mAh, also at 30w.

We’ll see the difference this makes in practice shortly.

Charging

Advantage: Mophie

The Anker comes with a rapid charger which charges it in a claimed 4.5 hours (I couldn’t test this, as the charger is US-only). The Mophie doesn’t, but it does offer pass-through charging – though only for the secondary devices. (This corrects an earlier misunderstanding of Mophie’s claims for the device.)

The Anker doesn’t support this, so has to be charged separately.

Ports

Both units have a bi-directional power deliver USB-C port, meaning that you use the same port to charge them as you do to power a MacBook/MacBook Pro. The Mophie has one 2.4A USB-A port which you can use to simultaneously power a second device – like an iPad – while the Anker has two of these in the UK version, allowing you to power a MacBook, iPad and iPhone at the same time. The U.S. version has three ports.

Portability

The extra capacity of the Anker doesn’t carry much of a size penalty, but it weighs almost one-and-a-half times as much as the Mophie.

The Mophie measures 5.9×3.3×0.9 inches and weighs a little under 14 ounces. The Anker is around an inch longer at 7×3.1×0.9 inches, but weighs a hefty 20.8 ounces. Both in your hand and in a bag, you can really feel the difference.

Look & feel

The Anker has a great build quality with a metal casing and plastic ends. It feels solid. The smooth surface feels like it might be a little slippery in the hand, but is actually reasonably grippy.

The Mophie has a wraparound fabric skin that makes it a bit more attractive than the usual bare metal, and also makes it easier to grip. Additionally, the combination of smaller size and fabric finish makes it look more discreet on a tabletop.

Power indicators

Both units have a button you press to display the power level. On the Anker, this is a large button on the the top of the casing. When you press it, up to 10 white LEDs light up, so you see the remaining capacity to the nearest 10%. These LEDs are in a circular pattern within the button itself, which has a suitably hi-tech feel.

On the Mophie, a much more discreet button lights up to four white LEDs at the edge of the top case. While pretty, these lack the same hi-tech feel, and more importantly only indicate charge level to the nearest 25%.

In use

I put both devices to the ultimate test: powering Apple’s most power-hungry MacBook, my fully maxed-out 15-inch MacBook Pro with Touch Bar.

Since this comes with an 87W power adapter, and both packs are limited to 30w output, I wasn’t expecting either to be able to fully power the MacBook. My initial planned test, then, was to start with 100% battery, plug in the powerpack and see how long it took to run down to zero.

But, to my surprise, both did in fact fully power the MacBook while it was in admittedly light use (mostly browsing). So I changed the test to a simpler one: start with a fully-charged laptop, disconnect the power, plug in the power pack and then time how long it kept the MacBook Pro’s own battery at 100%.

The Anker has 1.5 times the capacity of the Mophie, so in theory it should have powered the laptop for 1.5 times as long. It didn’t quite do so, but very nearly.

Mophie: 2h 31m

Anker: 3h 30m

Add that to the six hours real-life use I typically get when using the machine (rather a far cry from Apple’s claimed 10 hours), and that means I can get about 8.5 hours using the Mophie and 9.5 hours using the Anker.

Price

There’s quite a price difference between the two power packs. Despite the significantly higher capacity of the Anker, it sells for around 25% less than the cost of the Mophie.

Conclusions

There’s no clear winner here. While the final score was 5:3 in favor of Anker, it really depends what you need and what you value in a power pack.

If you want to maximize your usable battery life, then there’s no question: buy Anker. But if the Mophie provides enough of a boost for your needs – and you’re prepared to pay the price premium – then there’s a good case for choosing that instead. Pass-through charging makes it more practical, and the slightly reduced size and significantly reduced weight are also worth noting.

Bear in mind, too, that my battery-life numbers are the worst case. If you’re using one to power a 12-inch MacBook, then Apple says that the Mophie will add four hours of life.

For my part, the main need I have for portable power is on a long-haul flight where I may not have at-seat power. Getting me up to 8.5 hours total of real-life use is a full working day, and that’s as much as I’m going to want. So it’ll be the Mophie that slips into my travel case.