How much electricity will be used to charge a 4000 mAh battery?

i tried many to search it but cannot find a straight answer
so here is my question how many unit( kwh) of electricity will be used to charge a 4000mAh laptop or any other battery.
if further details are required
its 10.8V li ion
electricity on grid is 240 V 50 Hz.
7 answers 7