When it comes to external batteries, bigger capacity doesn�t necessary mean a better battery. Yes, we always look for the best price/performance/capacity ratio, but with batteries you need to figure out the capacity per need ratio. When you are at home and need a backup battery, get the largest capacity you can find � there is no need to drag it around so it could be as heavy as it comes. When you are traveling, maybe a compromise of a smaller capacity in exchange for a lighter weight is the better way to go. But for everyday portable use where you need an emergency backup � the smallest footprint with the largest capacity you can find is what you should be looking for. Even so Astro is already small and portable, it will be hard to beat Anker�s latest �lipstick� PowerCore+ Mini with 3,350 mAh.
I know some will say capacity of only 3,350 mAh?!? We get spoiled quickly with 10,000 mAh or 20,000 mAh external batteries, but when you take a look at this tiny 95 x 23 x 23mm (3.7 x 0.9 x 0.9in) size lipstick cylinder in a quality aluminum drop-tested shell with a weight of only 3oz � you will really appreciate size/capacity ratio. On top of that, it comes with Anker�s typical drawstring small storage pouch and a quality usb to micro usb cable. And since it�s available in a variety of colors, including some colorful pink and blue finishes, this battery can also be used as a �fashionable� accessory for the ladies.
The design itself is very minimalistic and elegant. I already mentioned about aluminum shell finish which feels very solid in your hand and gives you extra peace of mind if you accidentally drop it. The shell covers the entire cylinder in one solid piece, leaving only the top open where you have full size USB port to connect cable to your phone or tablet, micro USB port to charge this battery, and a small led/power button. To display the charging capacity, led has 3 colors to indicate: green 50%-100%, yellow 20%-50%, and red 5%-20%. It�s obviously not as accurate as Astro�s 10-led indicator with 10% increments, but considering this small footprint � it works fine. Plus keep in mind, most of the time you will probably get one or two full charges from this battery, so accuracy is not as important.
In terms of performance, Anker mentions it uses a premium Panasonic cell which is always a plus. The battery itself has a rather high efficiency of almost 92% (confirmed) which means you still get a solid 3,080 mAh of charging from this battery after internal 5V conversion through usb port. Most of the other lipstick batteries are typically in 80% efficiency range due to less efficient converters. The charging of the battery itself will not be lighting fast since input port is 5V at 1A, so expect a little over 3hrs of charging from empty. The ext charging port is only able to supply 1A of output power at 5V, though I actually confirmed it to provide 1.2A with my Note 4. It does offer PowerIQ intelligent charging current adjustment, but it doesn't matter since you are not going between 1A, 2A, or 2.4A charging speed. Most likely it will run around 1A-1.2A which is OK for emergency charging when you are on a go.
Overall, if you are looking for a super portable external battery for your phone or tablet, and need the smallest compact footprint to put it in your shirt pocket or a purse without adding too much weight, and still want to have enough capacity for emergency fast charging � this new Anker PowerCore+ Mini might be the one for you. 3,350 mAh is a pretty good capacity for on-the-go emergency charging, and if you factor in high efficiency, quality build with aluminum solid shell, included travel pouch and usb cable, and Anker�s 18-months warranty � this is one cool gadget to keep with you in a pocket for under $20.
Here are the pictures.