5V Battery Pack

• $10 each, 10000 mah 5v [1]. 50W if really 5v, but another produce said 37W.
• take a look at these reviews - https://www.pcworld.com/article/3236420/best-power-banks.html
• This reviewed is 50W - not bad. [2]
• Expect 30Whr from a 10A bat pack [3]
• But only 300 cycles? [4]