Charging For Two on the Go: Just Mobile Gum Max Duo

Tech Test Lab Review

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Product: Just Mobile Gum Max Duo
Price: $129.95
Rating: Recommend*

For many of us, our mobile devices have become our constant digital companions, always at our side wherever we go. But these devices are notorious for battery drain after a day's use, and it's not uncommon to discover an empty battery even before dinner time. The Gum Max Duo aims to solve this problem, multiplied by two...

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The aluminum Gum Max Duo ships with the charger pack, a black silicone sleeve, and a short USB-to-MicroUSB cable.

The Just Mobile Gum Max Duo is a backup battery providing 2 simultaneous charging USB ports, compatible with Micro USB devices (a short Micro USB cable is included; it's a case of BYOLC, "bring your own Lightning cable" for newer iPhone/iPad users). The single button on top of the handsome brushed aluminum case offers a charge indicator with 8 green LED lights, displaying how much power is available from the 11.200mAh capacity battery to transfer from the Gum Max Duo to your charge-thirsty portables. To top it off (literally), the battery is protected by a protective black silicone jacket, offering an extra layer of protection for throwing one of these charging devices into a travel or laptop bag without damaging or denting.

Testing: Testing out the Gum Max Duo proved to be simple and super fast. When my iPhone 5 was down to 25% battery life, I attached my own Lighting cable to the 1 amp USB port and regained a full charge in a little over an hour. After doing some math on the battery capacity, I realized this back-up battery could easily charge my iPhone 5 up to 7 times without needing to be recharged itself, an impressive feat for the modest sized peripheral.

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Connecting the Gum Max Duo's 2.4 amp USB port with my Retina display iPad added an extra 7 hours of use throughout a day. To offer perspective, the capacity of the iPad's battery is only slightly larger than the Gum Max Duo. The unit doesn't fully charge the iPad, but it comes very close to topping off the battery. And keep in mind, this high-capacity battery will charge your partially drained iDevices simultaneously.

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The black silicone sleeve is included. Additional colored sleeves are available for $12.95 each.

Bringing along this battery back-up to Dwell on Design for real world travel testing proved to be very handy for my girlfriend and I as we walked all day across the Los Angeles Convention Center halls last week. Snapping Instagram pics, capturing Vines, and checking Facebook all day sucked down our iPhone batteries pretty quickly. Once our iPhones were in the red, we were able to quickly recharge our devices at the same time, killing two birds with one stone. 

If you know you're going to be heavily using your phone or tablet for business or pleasure away from charging stations, especially with another user around, then I can recommend the Gum Max Duo as an ample power and capable portable battery option to bolster mobile devices charge capacity. It's a little pricey, but with its dual charging ports and fast charging times, the insurance of having a fast charging and capacious power source could easily pay back its worth with just one "I need to charge my phone now!" emergency.

Pros: High-capacity battery excellent for travel, quick charging, dual USB ports simultaneously charge two devices at once, silicone case for extra shock protection.

Cons: Pricey, charger battery takes a long time to recharge once drained, while compatible with other devices, it's made specifically for iPhone and iPad.

Our Ratings:

Strong Recommend
Recommend*
Weak Recommend
Don't Recommend

(Images:Vahan Baladouni/Just Mobile)


Apartment Therapy Media makes every effort to test and review products fairly and transparently. The views expressed in this review are the personal views of the reviewer and this particular product review was not sponsored or paid for in any way by the manufacturer or an agent working on their behalf. This specific product was provided by the manufacturer for testing and review purposes.

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