When we first saw Chinese battery developer Mipow’s products last Summer, we were intrigued by the design but not too impressed by the results; its Power Tube 2200 earned a C+ rating for underwhelming charging speeds and battery performance. That was then followed by Power Tube 3000 + 4000 in the fall, both of which represented a marked improvement and a new body shape. Now the company has released updated versions of both designs — Power Tube Shake 2600 ($46) and Power Tube 5500 ($99) — each including larger cells and a handful of other changes. Both Power Tubes have housings made from anodized aluminum in a very wide variety of colors, unlike virtually any other battery packs you’ll find on the market.
When you first see it, it’s hard to distinguish Power Tube 5500 from its predecessor. The shape is almost exactly the same, which is to say an extruded rectangle despite the “tube” name. We liked that the original version had a cap that popped off to reveal integrated Dock Connector and USB plugs; unfortunately, this one drops those in favor of bundling in a bunch of different cables and tips, plus a bag to hold them all. You connect the cables to a pair of ports on one end.
If you want to charge your iPhone or iPod—this Power Tube still only outputs 1A, so it’s not fast enough to properly charge an iPad—you have to carry around either a proprietary Dock Connector cable or a self-provided one, and another cord for recharging Power Tube’s battery when it’s drained. In exchange for losing the convenience of an integrated cable, Mipow instead gives you an LED flashlight. Yes, it works fine, but does it add any real value? We’d lean towards “no;” the older design was smarter.
Compared to the higher-capacity Power Tube 4000 as well as several other batteries, we were pleasantly surprised by the performance the 5500 mAh cell delivered. The capacity was so high that we alternated back and forth between an iPhone 4 and an iPhone 4S, both of which were connected to cellular and Wi-Fi networks, had the screen turned off, and had no media playing. Between the two, the cell provided a total charge of 244% before running dry, which is to say two full recharges and nearly one more half recharge. Based on results we’ve seen from other units, this was higher than we expected. If you extrapolate figures from the 4000, which was underpowered, the Power Tube 5500 should have delivered only about a 191% charge.
We wish that the battery supported 2.1-Amp charging so that we could see how it does with an iPad, but at 1-Amp speed it’s simply impractical to use, particularly with slow-charging third-generation models.
Power Tube Shake 2600 is closer to its precursor aesthetically, but adds new features too. This legitimately tube-shaped battery has greater capacity, and also adds in multicolored LEDs that display an approximation of the charge level. To activate the lights, you physically shake the battery, and will hear something shaking around inside. Thankfully Mipow bumped up the output from 0.5A to 1A, so this unit can charge iPhones at full speed.
The last version came with a bounty of charging cables, while this one trims the selection down to just five. Since there’s just one port on the device, you must swap cables in and out, with a proprietary plug at the end of each. In our testing, we were able to recharge an iPhone 4S 106%, and the speed lived up to the 1-Amp promise. The supplied power result fell somewhat shy of what we’d expected, but it’s roughly in the ballpark.
When we reviewed Power Tube 4000, we gave it credit for the ingenuity of the industrial design, but were a bit disappointed by the capacity.
