External batteries are a necessity when using a smartphone, and it stands to reason that the bigger the battery the more time you can spend away from a plug. When we went to CES 2013 in January, Judie, Carly and I brought multiple external batteries. For the first CES ever, we didn’t run out of fuel or go running for a plug half way through the day. Among my battery “arsenal” were a few of Just Mobile’s Gum series of backup batteries. I loved the look, feel and build of them, but I didn’t love only being able to charge one of my many devices at a time. Now Just Mobile has released their Just Mobile Gum Max Duo external battery. It improves on their other batteries in a number of ways. Here’s a video look and then a few more details.
As you can see in the video, this is a big, powerful battery. I love the fact that the aluminum is protected by the rubber cover. It does, however, introduce one small issue. More on that in a bit.
Just Mobile always offers great package presentations, and the Just Mobile Gum Max Duo is no exception. The box opens and reveals a window that allows you to see the Just Mobile Gum Max Duo before even opening the box. Is the extra expense worth it? I’m not sure, but it does make a nice impression.
As noted in the video the Just Mobile Gum Max Duo comes wrapped in a black silicon cover. The cover it great because it protects the battery, something that is especially important when a metal as soft as aluminum is used. The problem is simply the fact that you can’t really tell how much charge the battery has as the indicator lights are on the top and, as a result, they are covered by the silicon.
The Just Mobile Gum Max Duo has the moniker “Duo” thanks to the dual USB posts. One port offers 2.4A while the other just 1A. Obviously the first is for charging a tablet while the second is for most smartphones. Being able to charge both my iPad mini and my iPhone at the same time is a great convenience. And the fact that this battery has more than 11000mAh capacity makes it quite useful for any purpose.
The huge Just Mobile Gum Max Duo is charged using the tiny microUSB port. I know that is not surprise in 2013, but the contrast struck me as amusing. Of course, the company includes a USB to microUSB cable. That would not be worth mentioning except for the fact that they include an exceptional short cable that is ideal for throwing and keeping in your gear bag.
The black silicon case comes off the Just Mobile Gum Max Duo quite easily and reveals the beautiful aluminum of the battery.
On top of the Just Mobile Gum Max Duo you will see the power button and the eight indicator lights that show how much charge you have when the power button is pressed. They are, as noted, hidden when a case is on. I would have preferred them being on the portion that remains exposed.
The Just Mobile Gum Max Duo can be personalized with one of three additional covers. Each is just under $13 and is great if you want to match your external battery to your shirt… or bag… or iPad case… or hair color. Seriously I don’t fully get why you would want a different color, but obviously there is a market for this.
And if you have all four colors of Just Mobile Gum Max Duo sleeves you can make a Just Mobile Gum Max Duo pyramid. 
All kidding aside, this is a fantastic product and one that any and all road warriors should consider buying. It has a terrific design, it is simple to use, it offers a huge capacity battery, and it will charge two devices at once. At just under $130 it is pricey, but the design, capacity, and functionality of the Just Mobile Gum Max Duo are excellent. It is coming on my next trip with me, for sure! You can learn more and order yours here on the Just Mobile website. And while you are there, check out their other products; we love them and think you will, too.
MSRP: $129.95
What I Like: Huge capacity; Love the design; Easy to use; Charges phone and tablet at the same time; Includes short USB to microUSB cable; Battery is protected by the silicone sleeve
What Needs Improvement: Charge indicators are covered by the sleeves; I really don’t get why I would want a yellow sleeve. Then again I’m color blind
Source: Manufacturer supplied review sample
Related posts:
Just Mobile Gum Plus Back Up Battery Review
MiPow Power Cube 8000M Backup Battery Review
Just Mobile Gum Max Backup Battery Review
Accessory Review: Charge Your Mobile Devices With The Power Of The Sun
Tekkeon TekCharge MP1580 review
Review: i.Sound Portable Power Max 16000 mAh External Battery
Mobile Device Accessory Review: Juice Pack Powerstation
Review: Tekkeon TekCharge MP1860A Dual Port Power Pack
