Although it’s most well known for its battery cases, Mophie also produces standalone external batteries, including Juice Pack Powerstation ($80) and Juice Pack Powerstation Duo ($100). The two share the same look, feel, and materials, but differ in their physical size, capacity, and number of outputs. You get either 4000 or 6000mAh of 2.1A charging capability in an elegant box, with Powerstation Duo offering a second output port. Neither comes with a cable, so you’ll have to provide your own Dock Connector or Lightning cords.
Naturally, Powerstation is the smaller of the two units. It measures 2.28” wide, 4.09” long, and 0.53” tall—shorter than an iPhone 5, but thicker, and about the same width.
The top and bottom surfaces are black, soft-touch coated plastic, while the edges are dark silver metal. At one end you’ll find a single USB port, next to a Micro-USB port for recharging; the cable is included. Around the corner is the power button, and there are four battery indicator lights. Powerstation Duo is almost identical, although it’s 0.21” longer, and 0.25” thicker, and has the aforementioned extra USB port.
Both battery packs are capable of putting out 2.1A of power, total. For Powerstation, it means the unit is capable of recharging most devices at full speed, except for the third- and fourth-generation iPads which can take 2.4A.
Even though Powerstation Duo can handle two devices, the max of 2.1A means if you plug in an iPhone while your iPad is charging, it’ll slow the tablet’s recharge speed. Two iPhones or iPods at the same time will be fine, but Mophie suggests not charging two iPads at the same time.
We tested both batteries with a fully depleted iPad mini connected to Wi-Fi. The standard Powerstation was able to provide a 63% charge in just about an hour and a half. That’s a very respectable recharging ability, both in terms of amount of charge provided and the rate. Powerstation Duo came up to 105%—that’s 10% more than the 50% larger capacity would suggest.