[General Accessories] opasha:
Since vectron already did a great review on the Astro 3, I wanted to just add my own small input/experience with this great battery in his thread rather than creating a separate thread because I feel it would just add clutter. If I missed anything important, please refer to the OP because he's done a great job on outlining this battery's use/specs/details.

In my experience after using it, I can easily say that the Anker Astro 3 External Battery is a solid device. It packs a solid 12,000 mAh worth of power. I have used external batteries and power packs before. My previous version was the Anker Powerbank 8400mAh. This was a good device, but being a few years old, it cannot compare to the speed and power of the latest Astro 3. I have a Samsung Galaxy Note 2 (with a stock Samsung 3100mAh battery). This battery can and has charged my phone successfully to almost 4 full charges. I use my phone quite a bit with both my 4G LTE data and my 5 Ghz wifi connection. Now, we all know that the biggest battery hog of this huge phone is the screen. I use GPS a lot so the screen is always on in the car for that while simultaneously playing Pandora or YouTube videos for music. Typically, this will cause my phone battery to drain quite easily after heavy use, which is where a fast charging external battery like the Astro 3 becomes very useful.

Technical Specs: The battery capacity is 12,000 mAh/3.7V. Surprisingly, the battery maintains the level of charge when not in use, which can be rare as some batteries lose juice while sitting around much like a sleeping computer. The Astro 3 has a nice smooth black matte finish while the ends where the usb ports are have a glossy finish. The size is 11.1 x 8.3 x 2.6 cm. Almost like a nice thick wallet, it's comfortable to hold in one hand without issue. It weighs about 300 g/10oz but actually feels lighter in the hand. There are 4 ports - 1) Input Micro Usb port to charge the device at 5V/1.5A 2) Smart Usb Output port to charge an external device at 5V/2A (max) 3) Universal Usb Output port charging at 5V/1.5A (max) 4) Universal Usb Output port charging at 5V/1.5A (max). I have thoroughly tested each of these ports with my Galaxy Note 2 and my brother's Galaxy S3. The Smart port is very intelligent and charges the phone at a max of 2A which is great for my Note 2 - Note 2 can charge at the max 2A allowing for much faster recharge. The faster your ouput from your external battery with a matching input charge allows for such convenience. Many don't realize this. Nowadays we buy external batteries without understanding this number. If you buy an external battery that only charges your device at 1A, then your phone can only suck out that much juice at a time even if you have a newer phone that has a higher input (2A input from Note 2). This leads to longer charging time. The input charging rate for the Astro 3 is 1500mAh/h which is pretty fast for an external battery of this range. This allows it to charge from 0-12,000mAh in about 7-8 hours give or take if you are using a strong wall charger. I use a 1.8A blackberry play charger that works flawlessly to charge both this and my Note 2. A small/efficient charging micro Usb cable (about 8-10 in. long) comes with the Astro 3, which makes charging fast/easy.

Uses: The Astro 3 is quite easy to turn on. Just shake the battery to turn it on before you start charging your device after you plug it in, which is pretty smart. The device won't waste charge after a phone has been completely charged. It will shut off. Again, if you shake when nothing is plugged in, the Astro 3 wakes for about 10 seconds to show you how much charge is left by showing a circle of 10 LED lights. I assume this is for each 10% of the battery. It's pretty nice because it animates as it charges and when it shows you how much is left. I mentioned that I'm quite a power user when it comes to using my phone, especially when I'm on the road. I use GPS and Pandora on full brightness constantly. The Astro 3 is very portable and can be left in my car or placed in my rear pocket with the carrying pouch provided (the pouch is made of soft mesh and has a drawstring that can be easily carried in one's hand). Granted, you won't be carrying it in your pocket all the time, but it is nice to know that it can be taken with you on the go when necessary without making your hands full. When I'm home, I just leave the Astro 3 in the main living room for anyone who is to lazy to get up and go plug in their phone to their wall charger. This is a nice convenience factor for most external batteries. I also like the fact that the battery doesn't get very hot when charging my devices.

Ideal Consumers: This device is great for literally anyone, especially those who need a lot of power on the go for a single device or multiple devices. The amount of power it packs for its small size is really quite impressive. If you're someone who uses their phone for web, gps, music, movies, etc on the go, the Astro 3 is definitely worth getting. Even if you're not a power user and are too far from an available outlet, this device is very useful. I actually forgot my charger at home one day when going out of town, and had packed the Astro 3 in my car luckily before, which saved me during that weekend where I was constantly using my phone GPS and making phone calls/texting all day.

Final Thoughts: I am very satisfied with the Astro 3. I use it regularly and can't recommend it enough. I have used the old Anker 8400 Powerbank, and it still is working nicely to this day despite not being as fast and powerful as the new Astro 3. I also bought the new Bluetooth 4.0 headphones Anker just released, and they are absolutely great for sound quality, battery life, and just the flexible nature of their design. My brother loved the Astro 3 so much and wanted something even more portable, so I ended up buying him the Anker AstroSlim3 6000mAh external battery. Yes, it's half the power, but it's just as slim and similar in size to the Galaxy S3 that he has. Plus, his battery is only about 2600 mAh so he gets almost 2.5 full charges from it, which is not bad if you want something ultra portable. However, if you're someone that is out and about quite a bit or just find charging your phone by an outlet to be an inconvenience when you need to use your device for something important, buying a large mAh external battery like the Astro 3 is worth it.