The major rule for every smartphone is that YES, they should be charged once a day.
I do every night, so it's not really an issue.
Now, it all depends on the size of the screen, and of course your usage of the phone. But I believe that with a pretty normal usage, you're probably better off charging it every night.
I mean, mine often have like... 65% left at the evening, but I know that if I for some unexpected reason had to use it for a longer time tomorrow, I would be really stupid not to charge it now.
Most people I know just charges it every night to avoid any battery issues
