Is it OK to charge your iPhone 5s anytime at above 20% charge?

And help me out the phone runs out very fast and good app ppl say battery doc is crap and… So on

Added (1). i've let it couple of times like less than 12 times at 1% charge and thrice 0% bad?

Wanna know a secret? Apple employees are guys hired of the street and get a few days of training before they start 'diagnosing' your phones issues. They aren't jeenyisis who can do no wrong. I would take it to the tech people who work for your carrier. They won't lie to you because they don't have to represent apple. And they won't try to sell you another phone after they already sold you one with a software issue.

I used to charge my phone few times a day and now the battery doesn't stay for long. I read that, you shouldnt charge the phone many times a day. And do not use the phone while its charging. That ruins the battery, thats why the cables arent long.

Yes charge anytime. That is good for iphone battery.

Yes. If you let the battery run too low, it can shorten its life.

I have never had a battery issue, I always charge mine when its between 15% and 30% (I charge overnight).