Product review: Unifun 20000mAh Power Bank Backup External Battery

♦ size: 6 1/8" x 3 1/8" x 7/8"
♦ weight: 1 lb 1 oz
♦ number of ports: 2
♦ flashlight: no
♦ pass through charging: no (i.e. the battery can charge while being charged itself)
♦ cable: 21.5" charging cable

This external battery as not as large as one might expect for its large capacity of 20000 mAh. It has two ports and came with a charging cable (charging cables charge at a faster AC rate rather than USB rate). It has a bright blue charge level indicator.

This charger performed very well with both my Android phone and iPadMini. I am including the details of the tests at the end of the review for those who are interested in the nitty gritty numbers.

To see how well different external batteries charge my mobile devices I use a Nexus phone and an iPadMini to test each of them. The current drawn on each port depends on each device using the charger. The port rated with a maximum capacity of 2A does not always deliver 2A, what is actually delivered is controlled by the device based on many factors such running apps, level of charge, and so forth. I always use the same devices and I do my tests with the devices charged to the same level, running the same applications and using the same cables to keep everything the same. This allows me to do a relative comparison of various external batteries and identify the ones that do not perform well. Note that these tests are not testing for the maximum current each device can draw on each port because I do not own devices that can max out the current draw.

I also tested to see if the battery supports pass-through charging (i.e. whether the battery can charge mobile devices while it is being charged). This battery does NOT support charger through charging. It can not charge while being charged.

In addition to testing with my own cable, I test the cable included in the package to see if it is a charging cable or a data cable. This package includes a charging cable. For Android devices it matters if a cable used to charge the device is a charging cable or a data cable. Most of the time external batteries come with a charging cable, but every now I run across a manufacturer that encloses data cables with external batteries. It is not easy to tell what cable you got unless you have a current monitor. I always include this test in my reviews so people can improve the performance of the battery by switching to a charging cable.

Samsung Nexus phone:
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1A port: 1.00/5.00V (excellent)
2A port: 0.91/5.01V (excellent)
(for comparison the best charging monitor result for this phone is 1.00A/5V)

iPad Mini tablet:
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1A port: 0.92A/5.01V (average for 1A port)
2A port: 1.45A/5.02V (excellent)
(for comparison the best charging monitor result for this tablet is 1.70A/5V)


You can find it on Amazon by following this link.


Ali Julia review ★★★★★