GadgeTell Review: Second Generation Anker Astro3 12000mAh Battery

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These days, it’s hard for the gadget-obsessed to use products without feeling the drain. Tablets, smartphones, wireless headphones, and more can never really keep up with demand. Sure, there are outlets in public places such as coffee joints or libraries, but what about all those other times when you’re not somewhere you can just plug in?

Situations such as: reading from a tablet while relaxing at the beach, jogging on a trail or riding public transportation while listening to music, or taking photos while hiking or at an amusement park. The list goes on, where, ultimately, devices need an energy boost.

I’m no stranger to external battery pack solutions, and I’m always keeping an eye out for bigger and better ones to carry with me. When I saw that Anker was advertising their second-generation Astro3 as being 10% more efficient than anything else, I just had to see if it lived up to the hype.


I love the way the Anker Astro3 looks and feels. The flask-like shape is black with a smooth rubber finish to it. No gloss, no fingerprints, which is exactly how I like it.

When compared to previous versions of the Anker Astro, this one finally has the right dimensions with rounded edges.

Anker Astro3 Battery Pack 05

Notice the size and LED ring

The length to width ratio is similar to that of a pack of cards (or flask), which is why it holds well in the hand.

Unlike the older, flatter, candybar-shaped Astro models, this one can tuck away in clothing pockets and stay put.

The three output and single input ports are all located on the same side, which makes it easy to plug in cables. Other manufacturers, as well as Anker’s older designs, have the input port on a different side from the output ports. Not a ‘big’ deal, but it’s smarter in terms of cable flow.

USB ports are very snug, thankfully. I can’t stand poorly-constructed USB ports that wiggle room or let cables yank out too easily with the slightest nudge.

The Included 9” USB cable is a perfect length. I can charge my smartphone and have enough slack to use it without having to hold the battery or let it hang. The case is a nice addition for those who want to keep their Anker Astro3 pristine or have a place for loose cables or things. But not me. I prefer it nekkid.


You’ll find that there are no buttons on the Anker Astro3. If you want to start a charge or check the remaining power, just pick it up or give it a little shake. The front LED indicator will power up and give you an excellent approximation of the battery life left. The unit automatically turns itself off after 30 seconds if it’s not connected to anything.

Anker Astro3 Battery Pack 01

Ports are on the same side and clearly labeled

Instead of having to stare at four LED lights in order to guesstimate of the remaining stored energy, the Anker Astro3 features a circular LED indicator that’s segmented into 10 individual parts.

While receiving or delivering a charge, the LED circle slowly pulses, showing the current power level.

If you don’t see the LED glowing, then you know that charging in/out is all done. It’s bright enough to see from across the room (if you stand it upright) during the day.

I don’t know why it took so long to make these additions to battery packs. Though seemingly small, these features actually set the Anker Astro3 apart from the competition. It feels smarter, more streamlined, and less clunky.

One of the major benefits of owning the Anker Astro3 is the 4A total output of power. This is enough to charge up two tablets at the same time, or three lesser-devices that don’t require that much amperage. Smartphone, earpiece, wireless keyboard, speaker, etc.

The battery pack has a single ‘smart’ port, which is the ideal port for any and all iOS devices. The other two ports are geared more toward Android and generic USB gadgets. The box comes with a handy chart that details it all and makes it clear.


Anker advertises the Astro3 as being 10% more efficient than standard battery packs and/or the competition. This means that the 12000mAh Astro3 should deliver a usable 9600mAh (80%), whereas other 12000mAh batteries will only deliver 8400mAh (70%). That difference of 1200mAh is enough to fully-charge a typical smartphone.

Anker Astro3 Battery Pack 02

Sizes compared: 12000 Astro3, 10000 Astro 3E, 5200 Powergen

Note: Most external battery packs I’ve ever purchased and used came only partially charged, so I’ve always made it a habit to fully charge them before use.

I tend to fully charge and discharge a new battery a few times, just so I can level out the charge states of the individual cells. It helps to maximize the battery’s manufacturer-listed potential.

I ran battery tests with my Samsung Galaxy Note 2, with it’s whopping 3100mAh battery. I used the smart port each time; the included chart doesn’t list ‘phablets’ so I felt the smart one was the best choice. I mixed up the charging with long and short sessions to see if it made any difference.

Not only did the Anker Astro3 deliver on its promise of providing more total power, but it also surprised me with how consistent the output was. The first few tests showed that the Astro3 provided exactly three full charges to my Galaxy Note 2. I thought it was a fluke, since small variations in percentages are expected.

The next half-dozen tests all added up the same way. I’m sure I could continue on and eventually find margins of error, but I was already too impressed to care.

Doing the math, three times a 3100mAh battery adds up to 9300mAh, which is 300mAh short of what it’s supposed to be. Factor in 100mAh to keep the smartphone up and running during each of the complete recharges, and you’ve made it to that wonderful 80% useable of the 12000mAh total.


Anker Astro3 Battery Pack 04

Perfectly flask-sized!

If you’re still toting around cables and looking for outlets to charge your gear when you’re not in the house, you’re missing out on some serious freedom.

Owning the Anker Astro3 is like having a portable wall outlet that is pocket- and bag-friendly.

There are a lot of external battery solutions out there by a wide variety of manufacturers. For the most part, you can purchase any one of them and be content, knowing it’ll charge what you have.

However, not all battery packs are made the same. Anker proves itself as a leader among others with the refined design and greater efficiency of the Astro3. The price? Really hard to beat. You can pick up an Anker Astro3 from for $49. One could go with some unknown off-brand to save a few bucks, but why not stick with a brand that has been selling quality products for years?

Visit to check out all the other products and power solutions they make.

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