Anker's lipstick-sized Astro Mini 3,000 mAh portable battery charger is a best-seller on Amazon.com and receives excellent reviews. It's good for at least one phone charge with a little juice left over, reviewers say.
A portable battery in your pocket. Like our Best Reviewed portable mini charger, the Powerocks Magicstick (Est. $30) , the Anker Astro Mini 3,000 mAh is designed with the mobile phone user in mind. It comes in a lipstick-sized tube with a simple, aluminum design that's available in black, blue, pink or silver. This mini portable charger has a micro and full USB port with a power button on the end. The device won't work unless the button is pressed and automatically shuts off when disconnected, conveniently saving power. An orange light comes on when the battery is being recharged; it turns green when it's in use. The Astro Mini weighs 2.6 ounces and comes with a standard micro USB cable and travel pouch.
Battery charges a smartphone once. The Astro Mini is built with 3,000 mAh, slightly more than the Powerocks Magicstick 2,800 mAh, but powers one iPhone with a little juice left over, according to several users and reviewers. Anker says that 30 percent of the battery will be drained just by using the charger; as a result, most smartphones get one full charge. Two reviewers report it takes about three hours to get a 100 percent charge on a smartphone. (Powerock claims Magicstick can power up some cell phones twice before needing a recharge.) Recharge times on the Astro Mini and Magicstick are similar, around three to five hours. The Astro Mini charges faster using a wall outlet than via USB, but it's still easier to let it charge overnight, advises one Amazon.com user. Anker recommends using an AC 0.8 Amp adapter for a three-to-four hour charge.
Anker's lipstick-sized Astro Mini 3,000 mAh portable battery charger is a best-seller on Amazon.com, bringing in over 4,000 reviews and scoring a respectable 4.5 out of 5 stars. Some reviewers provide detailed analysis, including charge times for their phones and recharge times for the battery.
Review: Anker Astro Mini 3000mAh, Contributors to Amazon.com, As of April 2014
2. Winston's Humble Site
Engineer Winston Moy tests an earlier version of the Astro Mini, the 2,600 mAh, and finds it takes about three hours to charge an iPhone 4s; the Astro Mini's capacity runs at 68 percent, just about what Anker promises.
Review: Anker Astro Mini 2,600mAh External Battery, Winston Moy, May 7, 2013
Erica Ho is disappointed with the Astro Mini's performance -- it takes well over three hours to charge an HTC One S and has no battery remaining by the time the charge is complete. But Ho, who got two charges from her older Innergie PocketCell, declares the Astro Mini "does what it's supposed to do, and that is to give you emergency power and nothing more."
Review: The Anker Astro Mini Battery Adds Barebones Power, Erica Ho, Dec. 4, 2013
In this article on portable chargers, Forbes.com's Geoffrey Morrison gives the Astro Mini a brief mention as an option for small mobile-phone chargers. The Anker Astro 3 is the focus here, but its bulkiness (at least in the mobile charger world -- it's about the size of a smartphone but heavier) is a drawback.
Review: Great USB Battery Packs, Geoffrey Morrison, Aug. 5, 2013