I am a regular user of You tube and share/commodity trading software on my cell phone. I used to find very difficult to use my phone during travel as I had to use my phone very conservatively.
Bought Ambrane power bank 20000 mah about 4 months back.
It has excellent power backup. I normally use it during my travel which is generally once in a week and will be from 24 to 48 hours.
I can charge my mobile phone at least 4 times once during my travel and off late I am using my phone for continuous 5+5 hours without break.
Ambrane Power bank has 5 led indicators each indicator lasts up to 1 cell phone charge(samsung J7 prime) up to 100%. Cable provided with the power bank is of high quality and very flexible.
The only disadvantage of this power bank is it is little heavy and will not fit in
Before to buying this power bank I was finding it very difficult to use my smart phone due to poor battery backup.