New apple pro pencil isn’t charging for long periods of time

i got the iPad Air and pencil pro 2 days ago and it’s been charging for a bit (pencil) then stops charging until I take it off and start charging it again but I have barely used it as it doesn’t have much charge and it looses charge when I’m not using it. I don’t know what to do, it’s connected and works with the iPad but it is not charging right