I got the Anker PowerCore 20100 to replace a smaller Samsung battery pack when I was halfway into my hike on the Continental Divide Trail in 2015. I used it to charge my smart phone and bluetooth headset for the remainder of the CDT, as well as on the Te Araroa Trail and on the Hayduke Trail.
I paid $41 for the power bank at Amazon.com. For that price I got the battery and a USB cable, but wall adapter was not included.
The battery weighs in at 359 grams (12,7 oz) and measures 166 x 58 x 22 mm (6.5 x 2.3 x 0.9 in).
I really like the design of the PowerCore 20100. It’s simple and no frills. There is one micro-USB for input and two standard USB ports for output. The battery has 4 LED lights to indicate the charge and status of the battery. The lights come on when the battery is being recharged or connected to other devices, or when the button on the side is pressed.
The battery is rated at 20100 mAh storage capacity, but like with all batteries there is efficiency loss due to heat etc. when discharging the battery. I was able to get around 5 full charges on my Samsung Galaxy S4, around 13000 mAh, from a fully charged PowerCore 20100.
According to Anker the PowerCore 20100 is able to output 4,8A, 2,4A per USB port, but I was never able to test this since my smart phone only draws 1,2A when charging. The PowerCore 20100 recharges at up to 2A, depending on the wall adapter being used, so recharging the battery can take quite some time if completely empty, 10-12 hours or more. I would normally plug the battery in as soon as I got in to town and just leave it charging overnight.
One thing I don’t like about the PowerCore 20100 is the IQ smart charging technology. Instead of a physical on/off switch it has software to control the output and to cut the power when connected devices are fully charged. When I use it to charge my Bluebuds X or Jaybird X2 bluetooth headsets, which only have 85 mAh and 100 mAh batteries, the charging current is too weak and the PowerCore cuts the power. In order to charge my bluetooth headsets from the PowerCore I always have to charge them together with my phone or some other more “power-hungry” device to keep the power flowing.
Another minus is that the PowerCore 20100 does not support pass-through charging, i.e. the ability to charge other devices while it’s connected to a wall charger.
All in all the Anker PowerCore 20100 is a great battery pack though. When I go hiking I use my smart phone both for listening to music and for navigation, and the PowerCore 20100 manages to keep both my smart phone and bluetooth headset charged for up to a week on trail. For shorter trips I might bring a smaller battery pack, but for long trips off the grid the Anker PowerCore 20100 is a great battery pack. I find it well worth the $41 I paid for it.