Charging MacBook with an External Battery Pack

Apple’s newest MacBook, the 12″ model released in April of 2015 (and simply called the “MacBook”) offers amazing portability, acceptable performance, and decent battery life.  Where “decent” means I will be sweating around 4pm because I am not certain I will get through the rest of the meeting. I decided to test the MacBook with some external batteries to understand if they would be of help.

Background on the MacBook and Charging Options

I was excited to get the new MacBook, adding it to a mobile technology arsenal that includes a 13″ 2014 MacBook Air, a Microsoft Surface Pro 3, a Microsoft Surface Pro 1, an Apple iPad Air 2, and a Samsung Note 10.1 tablet running Android. Three of these can be charged from an external battery that has a USB port and the appropriate cable (the MacBook, iPad Air 2, and Android tablet). The MacBook Air 13 is the battery king among the group: it wins out at around 13 hours of regular usage so it easily goes all day (in fact I often leave the charger at home). Next up is the iPad Air 2 and Samsung Note 10.1 – each is around 10 hours. The Surface Pros are both capable of getting through lunch, but die sometime in the afternoon unless they are charged up.

When I ordered the MacBook, I was excited about the smaller size and weight (2 lbs!), but not as excited by the published battery life of up to 9 hours.  Apple has always been good about exceeding the rated battery life, but 9 hours may create an issue towards the end of the work day for me (yes, I know, first world problems).   The main issue the MacBook has which reduces battery life is the high resolution retina display, which at 2340×1440 pixels requires a lot more power to drive than the MacBook Air 13 with its larger battery and 1440×900 resolution.  While I appreciate the nicer screen images and font displays, I would be fine with a lower resolution and longer battery life.

The MacBook’s battery is a 5674 milliamp model, and the included standard charger is a 39-watt model.  Apple has foregone the usual proprietary MagSafe charger connections on this new machine.  Because they were proprietary, third party providers of power adapters or battery packs are few and far between, limiting user’s choices almost exclusively to Apple’s offerings.


What’s different about the MacBook that allows external battery chargers?

But the new MacBook uses an industry standard connector, the USB-C, to charge, so any manufacturer can offer something that could power or charge the MacBook (or connect it to a display, add a third party device, etc.).  This also allows third party external batteries that have USB ports and were originally developed to recharge a cell phone or tablet while on the go.  There is a wide variety of these, a search of Amazon or BestBuy reveals numerous choices from many manufacturers and of various sizes, shapes, capacity, and features.

I decided to test two of these batteries to see if I could eek out a little more time and get the new MacBook to a fuller day of work.

Tested External Batteries

I tried two external batteries, both ordered from Amazon based on descriptions and reviews there.

Anker 13000 External Battery

Anker 13000 External Battery

The first was an Anker second edition, model E4 (Amazon Link).  This one has a very low price at $29.99 and comes with a nice carrying case.  With 13,000 milliamps, it is weighs 10.4 ounces. but feels like carrying around a small brick; it just weighs more than expected when I pick it up. The shape is fine for sliding in a bag, but do not expect to fit it in a standard pocket anywhere.

The second is an Unu Ultrapack (Amazon Link), and at $99.99 it costs a lot more than the Anker, and weighs a bit less at 8.5 ounces.  That is almost 2 ounces, but means the Unu weighed about 80% of what the Anker E4 did. The difference is noticeable when both are picked up.  The shape is also smaller, and does fit into a bag better, or even a larger pocket (thank you

Unu 10,000 External Battery Pack

Unu 10,000 External Battery Pack

SCOTTeVEST!).  But the Unu also has a lower charge capacity, with only 10,000 milliamps.  This is about 80% of the Anker, so the reason for the weight and size difference is pretty obvious.


The Unu does offer one thing the Anker does not: a much faster recharge time (the time the battery takes to charge, not the time it would charge a connected device). The Anker uses a standard micro-USB connector, while the Anker uses a wall adapter and proprietary connector that can deliver more power, thus charging faster. In fact, they advertise that it can go from 0-100% in 30 minutes.  My testing did not match that (it was close), but there was no match between it and the Anker, which after took overnight and a bit into the morning to fully charge from an empty state. That could be very handy if the Unu could do the basic job. I also liked that the Unu has a digital output of percentage it holds, but the Anker’s 4 LED lights (0-25%, 25-50%, etc.) are serviceable for most users. Also from a features standpoint, both devices offered an LED flashlight, a nice touch.

There was one feature difference that I found important to note.  The Anker has two auto sensing USB ports, meaning that they could charge at 1 amp (suitable for a phone device), or 2.5 amps (targeted at a larger device like an iPad).  While 1 amp can charge an iPad, it is a slow go, so a 2.5 amp trickle is far more effective. The Unu also has two ports, but they are not auto sensing, so while each is marked (1 amp or 2.5 amps), you have to think about which port to use. With the Anker, you do not have to think about it, just plug it in and charge.  (Note Anker calls this “Power IQ”, and actually rates the output at 3 amps).

Results of Tests of Features and Charging  MacBook with the External Battery Packs

Charging MacBook Performance and Testing Methodology

This is the key issue: can it charge the 2015 MacBook 12″ model?  If it cannot do this effectively, why bother?

To test the charge capability of each battery, I ran the MacBook down to 25% battery capacity.  This simulates how my day goes, because when it gets here I start thinking about my schedule and options. Then in each test, I left the MacBook turned on, but closed the lid which puts it to sleep, then I connected the battery pack being tested and set a timer of 30 minutes.  I followed 30 minute intervals in which I opened the lid slightly and checked the battery %,  and then closed it again, and noted the % on the external battery. I followed this course until I had either charged the MacBook fully, or had completely drained the battery pack. In order to understand the scenario I face without the battery pack, I ran the same test with the Apple supplied AC adapter.  I used the same USB to USB-C cable in all tests, so the cable would not affect anything. I also ran the tests a second time with almost identical results, so I omitted the second results in all cases to make the information simpler to follow.

I did not test either battery while using the MacBook, I may at some future point.

The results were interesting, and can be seen below in a table and a chart.

Source AC Charger Unu Ultrapack Anker 2nd ed Astro E4
MaH N/A 10,000 13,000
Cost N/A $99.99 $29.99
Weigh (oz) N/A 8.5 10.4
Time in minutes
0 24% 25% 25%
30 56% 33% 37%
60 87% 40% 48%
90 100% 48% 59%
120 56% 70%
150 62% 81%
180 92%
210 99%

MacBook Charging Chart

Interpretation of Results

The AC adapter charged the MacBook from 25% to 100% in less than 90 minutes (the chart has an odd bend, but it was linear, and probably finished at around 70 minutes).

The Anker was able to fully charge, but took every ounce of the 13,000 milliamps.  It was tapped out at 0% when the MacBook reached 99%, and took 3.5 hours to get there.  It never got to 100%.

The Unu was not able to get beyond 62%.

Features Comparison

In terms of features, I found the Anker more compelling, while I would appreciate the percentage display available on the Unu, the Anker’s auto sensing ports was a winner for me.

Other Comparisons

The charge time of the batteries themselves varies greatly (how long does it take to charge an Anker or an Unu, not how long it takes to charge the device it in turn charges).  The Unu charges all the way in under an hour, the Anker takes about 8-10 hours.  This could be a serious issue, although the non-proprietary charging port on the Anker is helpful.

The only other issue was weight and size; in this case the Unu wins the head to head because it better meets a desire to stay light and quick.  

Summary of Charging MacBook with a Battery Pack

The only option I see between these is the Anker.  The Unu is nice, but cannot charge the MacBook to the degree I would like. If you only want about 40% (which should be about 3 hours of use), then the Unu could work, but I did not see the benefit of it, especially at over three times the cost. That is not to say that the Unu is poor device – it is intended to charge cell phones and tablets, and for that it does a phenomenal job, as does the Anker. But for charging the MacBook, the only reasonable solution between these two is the Anker.

But to be fair, when you consider that the MacBook is attractive to many because of how light and portable it is, it may not even make any sense to carry an external battery.  If the Anker is the best choice (and for the goal I had it is for me), the 10.4 ounces adds over ½ pound to the load and extra bulk. At that point, the MacBook 13 may be the better option to carry when on the go.

Other Info:

I found this article helpful on 9 to 5 Mac.

Learning from the New York Stock Exchange’s Technology Failure

The New York Stock Exchange (NYSE) experienced a serious technology failure this week of approximately 3.5 hours, after experiencing reduced functionality for the first 2.5 hours of the trading day.  The NYSE is of course a very high profile, internationally critical component of our financial systems.  System wide failures are extremely rare, and when they do occur they are publicized.  This allows us to consider what happened, and what we can learn from it that may help you.

What was the Technology Failure?:

The NYSE has numerous software applications that are integrated to provide a cohesive system for access and control.  There is the core record keeping system, systems to manage the process, customer systems to control accounts and execute trades, systems that monitor activity for fraud, etc. These systems exchange data with each other at various levels, and are dependent on being compatible and reliable.

On Tuesday evening, July 7, 2015, NYSE administrators applied an update to one of these systems to support a change in how the industry timestamps transactions. On Wednesday morning, July 8, 2015 the NYSE started noticing issues with communications between systems and applied an update to the customer system, this in turn created more issues.

The problem was not resolved, and at 11:30am the NYSE shut down trading and continued to work on the issue. At just after 3:00pm, non-updated backup systems were brought up in place of the production systems and operations resumed.

A quick synopsis can be seen here:

What do we learn that is applicable?

What does you SMB sized organization take away from this?

We may be able to continue operations. The NYSE must have a level playing field to allow everybody to execute trades at the same time, or else fraud or inequality of opportunity become an issue.  Your business may be able to continue operations without a complete shutdown if one function is limited or creating any data issues.  For example, if your customer service system is down and orders via the web cannot be taken, it may be possible to place a message holder informing customers they can call customer service to place an order.  You may need to temporarily reallocate staff to handle more call volume, but customers can still be serviced and a more intimate conversation take place during the transaction.

Systems are complex, especially multiple systems that communicate with each other.  Software, especially software designed for a specific organization and use, can be complex. The luxury of waiting for others to test it in the real world is not present.  So testing is essential and it must reflect the real world: real data, real transactions, real systems that mirror the production system with the changes tested applied.  The testing must be broad, rigorous and deliberate, and results must be tracked.  Automated test tools can make the process more efficient, but they are just pieces of software and must be setup and used correctly. When multiple systems are involved and dependent upon each other, they all must be exercised.

Disaster Recovery works, but is a choice to execute.  In this case, the NYSE decided to cut over to the backup systems to continue operations.  This is not the same thing as pulling a server out of the closet and installing everything and going back to operations.  This is a “hot system”, one that has all of the live data but was not updated with the errant code.  It is not a small decision to cut over, as there is normally a cut back process when issues are resolved, but one they could make because they had designed the systems for it.  This allowed them to resume operations while still dealing with the issue. Most small organizations do not have this capability, but they can, and can have it for a very economical price.  My firm, Keystone Technology Consultants, offers this for even very small clients of 20 users. It is not just a peace of mind issue; it literally allows an organization to continue operations and keep the flow of work and money, and maintain their reputation and client relationships. It is essential.

I would love to hear your view of this, feel free to comment below.