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HTC Source | February 20, 2018

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Anker Astro3 External Battery Review

Anker Astro3 External Battery Review

Do you find that at the end of the day, your HTC device repeatedly displays the low battery warning?  Or perhaps you have to charge your device constantly throughout the day in order for it to last?  If you’re like me, I use my phone heavily for both my work and personal life.  I currently use the HTC One which is an amazing phone but does have a tendency to eat my battery especially since T-Mobile rolled out the 4G LTE.  Although I am never far from a wall socket or a computer, it would be nice to have another option when either of those are not readily available..  Today I will be reviewing the Anker Astro3, which is an external battery.  Does it have what it takes to meet our battery needs?

Price: $49.99 on Amazon.


The Anker Astro3’s reminds me of the Western Digital Elements external hard drive without its slim factor.  It has a soft touch coating and and  has a small Anker logo on the center bottom.   The device is only available in the color black.  It is button less but has a smart LED light that will only show up if you shake the device or if you are charging it.

At a weight of  11 oz, the device  feels heavy when you hold it in your hands.  The body is also a little on the thick side but it is still quite portable.  It  has a capacity of 12000mAh and has four ports including a micro USB Input port, a smart USB output, and two universal USB output.

As far as accessories, the Astro3 comes with a small black pouch bag for storage, a micro USB cable, an adapter for the iPad/iPhone (pre-iPad/iPhone 5), and an instruction manual.  Unfortunately, this device does not ship with an AC adapter.


Charging the Anker Astro3 is a very simple task.  All you need to do is insert the provided micro USB cable in the input port and either insert the other end into an AC adapter (not provided) connected to a wall socket or plug it into a USB port in an active computer.  When charging, the smart LED indicator will light up.  In the shape of a circle, the LED shows the current level of charge by staying lit.  If it is not fully charged, it will display a cascading light to show the portion that is still charging.

The amount of time it took me to fully charge the Astro3 was very disappointing.  With one bar left on the LED, I plugged in the external battery to a wall socket at 12:30 am.  It did not reach maximum capacity until 6:30 pm the next day, which equates to 18 hours. Please note that this is the first external battery that I have ever used.  I am not sure if the charging time is better, worse, or on par with other similar devices.  Regardless, I was surprised on how long it took.

We already know how long it took to charge the Astro3.  Let’s find out how it performs when is used to actually charge devices.  This external battery has three ports, so you can simultaneously charge three difference devices at once.  According to the manual, when doing so, the total output current will not exceed 4A.  To compare, charging an iPad on the smart port by itself will charge at 2.4A.  With three devices charging at the same time, that number is going to be significantly less.  As we all know, every device charges differently.  The Astro3 is smart enough to only charge the capacity of the device that it is connected to so you will never have to worry about your device being damaged due to being overcharged.  However, it will never exceed the charging rate of 4A.


I decided to use my HTC One and 1st gen iPad to test the capabilities of this external battery.  Charging the HTC One from a completely drained battery took approximately 3 hours to fully recharge.  My phone was off so it might take a little longer to fully charge if I left my phone on.  After the charge, the Anker Astro3 had roughly 80% juice left.  Next I decided to charge my iPad from a completely drained battery as well.  Unfortunately, I neglected to measure the amount of time it took to fully charge the iPad.  If I had to guess, it took about 8 hours.  The iPad took about 70% off the remaining charge.  After charging both devices, there was only 10% left in the external battery.  It’s pretty impressive to be able to charge a smart phone and a tablet on just one charge.


Would I recommend the Anker Astro3?  In a short answer, I would say yes.  Having an extra battery is never a bad thing especially one that can fully charge a smartphone and a tablet.  The amount of time it takes to charge devices is excellent.  Although somewhat thick, it is still portable enough for travel.  The only knock that I would have about this external battery is the time it takes to charge the actual unit itself.  However, at a price of $49.99 on Amazon, it is definitely worth the purchase.

About Paolo C.


  1. Tomarone

    The adapter that you used might not be high capacity (was it for HTC ONE?) they are all different (some would charge faster than others) as will USB ports on computers have different charging (voltage I think?) I have an old Lenovo computer that actually charges when the computer is off (from it’s USB port) weird.

    • Tomarone

      12000mAh is a lot of capacity, to charge that, also, it might need to be slow otherwise it would over heat and catch on fire. You don’t want all that lithium burning up on you.

    • Paolo Calayag

      I did use the HTC One adapter. I will use a computer USB port next to compare the charging times. Perhaps there will be a significant different. I will update and let you know what I find!

  2. Hamk

    You can have a try RavPower 14000mAh if you think the capacity is not enough. This one is pretty stylish and portable, selling $43.99 only.