Dell XPS 13 9343 Laptop drains battery when shut down (20% per 10 hours).

Sorry for duplicate post, but subject was not particularly helpful.

Have new Dell laptop XPS 13 9343, with battery drain problem since day 1, drops from 100% to 80% overnight. Came with windows 8, but I updated to windows 10 right away, so not sure if this was happening from the word go.

The laptop is a bit warm on the underside first thing in the morning, so something is drawing power in the shut down state. Turned of fast boot and looked at bios changing anything that may looks like it may be causing a problem. Lap top just cannot seem to switch off !!

Updated bios and all drivers, as suggested on forum doing search for peolple with similar issues.

Seems to be a problem with intel MEI - and causes same issue on lots of laptops, not just Dell.

Unable to downgrade intel MEI to version 9 from 11 as I get error message something like "Thiscomputer does not meet minimum requirements for installing this driver".

Have zip file - MEI_Win7_8_8.1_9.5.24.1790_5.0M - how can I install (roll back greyed out as I assume 11 is what I have always had.

Could take battery out every night, but bit of a hassle I can do without !

What can I do ? Anyone else with this laptop have this issue ??

Thanks for any help, in advance.