MacBook shows it is charging when MagSafe is green

My MacBook currently shows this even though the MagSafe charger has a green light.

Does anyone know why this is?

If it helps I am on a MacBook Air late 2010 with 819 cycle counts, 4,995mAh (currently), max capacity is 4,995mAh and the original capacity is 6,700mAh. I am also running make in terminal which has set my fans on and is making my computer lag a bit since it has a lot to install.

Could the issue be the process it using a lot of power?