Student or Learner
Mina: Hey! Where is your mobile phone?
Me: I have kept it charged in my room.
Is the bold part okay?
UM Chakma, do you mean 'I left it charging in my room' or 'It's on charge in my room'?
Yes, exactly that is what I meant but unfortunately I didn't know how to say it. Now I think I can. Let's check.
I left it it on-charge in my room. (Bhai)
I left it charging in my room. (Rover)
Do both mean the same?
You wouldn't hear "on-charge" in AmE. We would say it was charging.
I've never seen or used "on charge" with a hyphen as Bhai wrote it. I would say "It's in my room, charging" or "It's on charge in my room". They mean the same thing - the phone is plugged into the mains power in order to charge the battery.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.