The Xiaomi 20000mAh Mi Power Bank is the cheapest set in this roundup, but it comes with a huge battery capacity of 20,000mAh.
Its rectangular plastic housing features an anti-slip textured pattern that is scratch-resistant and allows for a better grip.
It might be a tad thick but its size makes it just nice to hold with my iPhone 6s Plus. I also like the power button being sited on the side for easy access while gripping it.
On its top, there is a four-LED battery indicator, a micro-USB charging port and two USB output ports - both capable of putting out 2.1A during charging, and a combined output of 3.6A when used concurrently.
It took 68min to charge my iPhone from the halfway mark to full. It is only slower than the GP Portable PowerBank 3C20A in this round-up - an impressive feat considering it is the cheapest of the lot.
The only problem is getting one from Xiaomi's online store or retailers, as it always seems to be sold out.
•Verdict: In terms of value for money, the Xiaomi 20000mAh Mi Power Bank is unbeatable. That is, if you can find one.
BATTERY CAPACITY: 20,000mAh
OUTPUT PORTS: 2 x 2.1A USB
VALUE FOR MONEY: 5/5