I agree, mining Monero with consumer CPUs isn't the best choice, after accounting your electricity cost (For charging your phone, that is). To put in comparison, my i7-4500U has an average hashrate of 110H/s, plus, electricity is expensive in my country.
So I did an experiment mining Monero with Microsoft Azure free trial (still ongoing), you can check it out here!
https://steemit.com/monero/@casiotech/monero-mining-experiment
Based on the progress so far, I would say that it's going pretty well :)