This Week's Sponsor:

Collections Database

A Powerful Database with iCloud Sync


Gum Max Review

With a 2.1A output and 10,400mAh capacity, the Gum Max is an external backup battery by Just Mobile that works with iOS devices. Anyone who has used iOS devices extensively – perhaps some of you even use the iPad as their primary computer – knows that, for as much as Apple has focused on making iOS devices extremely user-friendly from a battery life standpoint, the battery is going to run out eventually. And if you use a lot of high-speed 3G data, watch some videos, and play a game or two, that battery indicator up in the iOS status bar is going to run out faster.

Just a few days prior to receiving my Gum Max review unit, I waited in line at the Apple Store in Rome to buy the new iPad. There, I had the chance to experience how important it is to be able to rely on iOS devices without a source of power constantly available – sure, Apple employees allowed us to use the store’s MacBooks to charge our iPhones, but it just seemed rude to me to go there every few hours just to grab a USB port without doing anything else. Waiting in line for more than 20 hours, using a lot of 3G and taking several photos of videos with my iPhone 4S, I had to recharge my device multiple times – and when I didn’t want to use the USB ports kindly provided by Apple’s employees, I had to use my friends’ portable battery packs. There, I realized I really needed to get a backup battery for iOS devices for the future. Indeed, power and battery life seem to be two common concerns these days.

The Gum Max is not one of those battery packs that you can use as a case for the iPhone. The Gum Max actually looks (and weighs) like an external drive, only it can charge iOS devices through USB. The device has a green LED indicator to show how much juice it’s got left to power your iPhone or iPad, and input and output (to recharge the Gum Max, and recharge your iOS devices) are separate, but they both use USB (regular and micro) through cables that are provided in the box. As with many Just Mobile products, the Gum Max looks like something Apple would produce, with a clean and elegant design highlighted by a sturdy aluminum shell. I like the design of the Gum Max, but how it works is what matters in critical situations.

I ran a series of tests to see how the Gum Max would recharge my iPhone 4S, iPad 2, and new iPad. Overall, the Gum Max can easily recharge an iPhone 4S from 0% to 100% in two hours, get an iPad 2 from 0% to 90% with a single charge, and recharge half of the new iPad’s bigger battery with a single charge.

Gum Max Tests

iPhone 4S, started at 3:47 AM. From 0% to 37% in 30 minutes; up to 79% after 67 minutes.

iPhone 4S, started at 11:15 PM. From 0% to 68% in 60 minutes; up to 98% in 115 minutes.

iPad 3, started at 1:10 AM. Up to 28% in 100 minutes.

iPad 3, started at 2:09 PM. Device turned on at 2:17 PM. Up to 35% in 122 minutes; 42% in 145 minutes; 51% in 176 minutes; Gum Max turned off at 5:05 PM with device at 52%.

iPad 2, started at 10:14 PM. Device turned on at 10:23 PM, reached 44% at 11:44 PM, Gum Max turned off with iPad at 90%.

At $109, you have to consider whether getting 5 hours of a new iPad back will be worth the expense, assuming you’re getting the 10 hours of battery life promised by Apple, which I have indeed noticed with my iPad (it is a 4G model, and I don’t keep brightness at 100%). Is a full iPhone charge or an iPad going back to 50% going to a considerable improvement for your work, or the way you rely on iOS devices on the go? And is that improvement going to be worth $109 over time? Especially for iPhone users, I think having a full charge back in two hours can be critical in some scenarios (last year, I spent a night at the hospital to help a friend, my phone died at 3 AM, and I couldn’t reach my parents). For third-generation iPad users, the utility of a battery pack like this is more debatable, as the new iPad is slower at charging, and it’ll completely drain the Gum Max while remaining at only 50%. For previous iPad owners, 90% of charge from zero sounds like a good investment in my opinion.

With these differences in mind, the Gum Max is a fine accessory, it’s very portable, and it comes with an elegant black carrying pouch. You can get it here.

Unlock More with Club MacStories

Founded in 2015, Club MacStories has delivered exclusive content every week for over six years.

In that time, members have enjoyed nearly 400 weekly and monthly newsletters packed with more of your favorite MacStories writing as well as Club-only podcasts, eBooks, discounts on apps, icons, and services. Join today, and you’ll get everything new that we publish every week, plus access to our entire archive of back issues and downloadable perks.

The Club expanded in 2021 with Club MacStories+ and Club Premier. Club MacStories+ members enjoy even more exclusive stories, a vibrant Discord community, a rotating roster of app discounts, and more. And, with Club Premier, you get everything we offer at every Club level plus an extended, ad-free version of our podcast AppStories that is delivered early each week in high-bitrate audio.

Choose the Club plan that’s right for you:

  • Club MacStories: Weekly and monthly newsletters via email and the web that are brimming with app collections, tips, automation workflows, longform writing, a Club-only podcast, periodic giveaways, and more;
  • Club MacStories+: Everything that Club MacStories offers, plus exclusive content like Federico’s Automation Academy and John’s Macintosh Desktop Experience, a powerful web app for searching and exploring over 6 years of content and creating custom RSS feeds of Club content, an active Discord community, and a rotating collection of discounts, and more;
  • Club Premier: Everything in from our other plans and AppStories+, an extended version of our flagship podcast that’s delivered early, ad-free, and in high-bitrate audio.