I’ve faced this issue with my new Lenovo Thinkpad E560.
Whether the laptop is in sleep mode or powered off, it loses complete charge. Most likely, this issue is caused by BIOS as it seems some components still working and consuming battery even if you power the laptop off.
I have two fixes for this:
– Temporary: After powering off, just unplug the battery and plug it again.
– Permanent: Update your BIOS, for me I updated to latest from Lenovo website.