How to tell if my dead iPhone 5 is charging?

Yes, I've tried googling this and a lot of responses came up. However, none of the situations where the exact same as mine nor did it answer my question.

I've always had trouble with chargers stop working after a couple of weeks, but I just figured it was because a lot of them weren't Apple-made. However, in the past two weeks, every two days I've been needing a new charger. I've probably been through around 10 in a couple of days and some of those were Apple, so I don't think that's the problem.

My first question is that I'm re-going through a lot of these "dead" chargers and trying them with different wall plug-ins and different outlets around the house. How do I know if its working? So far its been doing the red bar with the cord and arrow below it for all of them and I wasn't sure if that meant it was charging, so I've been leaving it for around 20 minutes, still no turn on.

Secondly: Why might my iPhone be doing this? It's recently been causing a lot of problems so I'm about ready to trade it in for a new one. First, though I want to get back on my phone one more time to make sure everything I need is backed up.

Poke em' n da gonads

On the home screen, there will usually be a battery symbol that indicates that your phone is charging
if it isn't charging, then the regular lock screen theme will show up
hope this helps