Model: Undead Power Helix
Compatible: All iPads, iPhones + iPods
Lenmar Undead Power Helix 11,000mAh Battery Pack
Ever since the third- and fourth-generation iPads debuted with unusually power-hungry screens, battery packs have jumped considerably in capacity to offer users on-the-road recharging options -- we've now seen more than a handful of options at or above the 10,000mAh capacity level, which is enough to recharge iPhones and iPods three to six times. uNu notably released the impressive $80 11,000mAh Enerpak Vault earlier this year, and Just Mobile released the $130 11,200mAh Gum Max Duo shortly thereafter; now Lenmar is selling the Undead Power Helix ($100) with a 11,000mAh cell inside. "Undead Power" appears to be the name of a full lineup of battery packs, so we'll refer to this one as "Helix" going forward.
Made from a mix of black, soft touch rubber-coated hard plastic and silver accents, Helix is thinner and narrower than Gum Max Duo, but a little bit longer, measuring around 4.7” tall, 3.1” wide, and 0.8” thick at its largest points. The shape is very similar—a rounded rectangle extruded and tapered in a manner that’s very similar to the iPhone 4, 4S, and 5, only larger. Helix’s single biggest advantage relative to earlier rivals is an unusual number of USB ports: one of its edges sports a 2.4-Amp outlet labeled “tablet,” plus two 1-Amp outlets labeled “mobile phone.” There’s also a small micro-USB port on an adjacent side, capable of refueling Helix at 1.5-Amp speeds—not super fast, but not terribly slow, either; like other high-capacity batteries, you should expect to leave it overnight to get from a full discharge to full capacity. A swirled metal power button near the USB ports reveals a set of four green and intuitive power indicator LEDs on a black plastic bar to let you know how recharging is going. One will flash to indicate that Helix itself is currently recharging; they’ll otherwise stay solid.
Having tested quite a few of these batteries in the past, we’ve seen models where there’s a lot to say based on packed-in frills—for insance, Gum Max Duo comes with a rubber protective sleeve, and has a nice metal chassis—but Helix is a bare-boned solution. You get the battery, a micro-USB to USB charging cable, and nothing else; you have to supply the Lightning or Dock Connector cables for your Apple devices yourself. Just like uNu’s Enerpak Vault, Helix doesn’t look or feel cheap, but it’s not particularly fancy, either. It’s good enough, not great.
We weren’t hugely impressed by Helix’s power performance, but it’s not bad, either. Despite the capacious 11,000mAh cell, we were only able to achieve a 57% recharge of a 11,666mAh fourth-generation iPad, which is below the 75% charge we saw with the 11,200mAh Gum Max Duo, as well as under the 70% achieved by the 11,000mAh Enerpak Vault. Additionally, the “2.4-Amp” USB port took over 3.5 hours to get the iPad to the 57% mark—closer to what we’d expect from a 2.1-Amp USB port. Although that port is labeled “tablet,” and the battery is obviously tablet-ready, Lenmar pitches this as good for up to seven recharges of other “mobile devices;” it’s closer to three or four iPhone 5 recharges, or a couple of iPad mini recharges.
In short, while Helix has the right on-paper credentials to stand out from its rivals, its actual performance is somewhat middling: don’t expect it to deliver quite as much iPad power as similarly-rated batteries, despite the specifications. It doesn’t outperform Enerpak Vault, even though it sells for $20 more, and doesn’t have any other frills as an offset. That having been said, its price tag is considerably lower than Just Mobile’s—18% less of an iPad charge for $30 less—and the presence of three USB ports might appeal to some users. Consider it most seriously if you’re hoping to provide spare power for an iPhone, iPod, or iPad mini, and mull other options if you’re in need of spare fuel for a third- or fourth-generation iPad. It’s good enough to merit a general recommendation for its price.