Just acquire 5401 for a couple of weeks, everything works properly, but I notice the battery will drop to 75% overnight after being "turned off" at the end of use. The laptop does not seem to be actually off but more like going into "sleep mode" which consumes power.
I searched over the Internet and do find quite a few examples of this kind, all Dell laptops. Some user feedback or youtube channels suggest deleting certain Intel programs, etc.
Can I get any advice to solve this situation which I believe I am not the only one facing it.
A number of suggestions on this web page that may help.
Thanks for the advices, the referred link does cover most of the solutions I could retrieve from the Internet.
And after a month of trying, all these "configuration" does not fix the battery drain problem. In the end, Dell offers me a new battery which seems to improve the situation (NOT SOLVE)--with the new battery the power consumption after turned off, let's say 8 hours, drops from 25% to 8-10%.
So every morning when I start working, I get a 90-92% battery. Which means if I stop using my Latitude 5401, the battery will drain itself after 2 days. I will test it with the new battery anyway.
Will return with the results after a couple of days.