rMBP 13 Battery Drain when sleep?

[kokhoong0624]

My friend have a rMBP 13 inch and when it sleeps for 7 hours, it drains 40% of battery. Does anyone have this issue and is there any way to resolve it?? D:

 

[laz1e]

see if the power nap option is checked in System pref -> energy saver, if it is, uncheck that option

 

[kokhoong0624]

It is off but the battery still drain a lot what can I do

 

[posguy99]

It is off but the battery still drain a lot what can I do

Does he have any USB peripherals plugged into it? Including an sd card?