This is a review of Anker 2nd gen Astro Pro2 20000 mAh external battery. Anker 2nd Gen Astro Pro2 20000mAh Quad-Port External Battery
, and amazon link: Amazon.com: AnkerŪ 2nd Gen Astro Pro2 20000mAh Quad-Port Portable Charger Fastest Backup External Battery Power Pack for iPhone 5S, 5C, 5, 4S, iPad Air, 5, 4, 3, 2, Retina iPad Mini 2, Samsung Galaxy S4, S3, Note 2, Note 3, Galaxy Tab, Google Nexus 4
In case if you thought I took a break from reviewing external batteries - I didn't. I was looking for something new and original, not another cookie-cutter re-branded battery. Funny how everytime I start my journey to find a cool new original battery product with a great value, I always end up coming back to yet another new release from Anker. As I mentioned so many times in the past, this company is working very hard to stay at the top of the game with new products and ideas. They switched to environmentally safe carton packaging (no plastic what so ever), updated to 2nd gen with more efficient modules having 80% efficiency in comparison to every other external battery out there with only 65%-70% efficiency, and introduced 10-led capacity indicators with their 2nd gen Astro modules. So where do you go from there? - 2nd gen Astro Pro2 with a whooping 20000 mAh (that's 20k mAh) capacity.
As I mentioned above, the battery arrived in Anker's new standard all carton packaging which is environmentally safe and no-hassle to open. Being a super high capacity, don't expect a lightweight portable module. I have seen a lot of other cheap 20000 mAh batteries in the past, all in a lightweight small footprint. That would be the first red flag to claim a high capacity without a "weight" behind it
Astro Pro2 is about 6.5" x 4.5" x 0.6" and weight of 488 g. It's not pocket friendly, but with included drawstring storage pouch and considering relatively slim profile - it would make a great travel companion in your briefcase or luggage. The case is very durable all metal with a brushed aluminum black finish which I found to be scratch resistant. Other accessories include usb to micro-usb cable, tablet charging cable (for Asus and Acer tablets with 5.5mm x 2.1mm jack), and AC outlet charging cable. With such high capacity charging this battery from usb charger will take a very long time, so the charging is done from 12V/2A wall charger where you can get full charge from zero in under 6 hours.
Once you start charging you will notice something that is extremely rare for external batteries - a back lit LCD display with actual % indicator number in 1% increments. There is no guessing with 4 leds or even 10 leds, you will know exactly the charging capacity and when using this battery - the exact remaining battery capacity. This capacity could be checked at any point by pushing multi-function button on the side of the battery. Also, when you hold this button down for 3sec, you will see a flashing 9V or 12V which can be selected with the same button. To accommodate some of the common Acer and Asus tablets with 5.5mm x 2.1mm jack, you can use included cable attached to DC Output port where you get 9V / 2A or 12V / 1.5A output. If you have some other tablet or camera or another gadget that require 9V or 12V voltage and uses a unique charging tip, you can get for $10 a collection of 28 different tips like these: Amazon.com: Vktech Universal 28 DC Power 5.5x2.1mm Jack to 28 Plug Power Adapter for Notebook: Computers & Accessories
But the stars of this external battery are 3x smart usb outputs, each being able to supply up to 2.4A. When all ports are connected, you can't exceed the maximum 4.5A current, but still it's very impressive considering you could be charging 3 separate devices at high speed from such a high capacity source. Also, the charging starts automatically once you plug in the cable. 20000 mAh is obviously the max capacity of the internal battery, but as you know it's typically 3.7V which has to be converted to 5V usb interface where the efficiency of Astro Pro2 is only 80% of the actual capacity, 16000 mAh. This is VERY impressive because today most of the external batteries on the market have actual capacity which is only 2/3 of the max advertised one.
Overall, I found this battery to be of a VERY high quality with a tough attractive built, multi-port smart charging capability including flexibility of 9V/12V charging, 1% increment charge/capacity LCD indicator, and one of the best warranty coverages with 18-months of support. Considering all that and enormous capacity of 20000 mAh with 80% efficiency, the price of $79.99 is actually a bargain for such product.
Here are the pictures.