Dell XPS 18 CMOS Battery Problem

I have a Dell XPS 18 (1810) i5. The CMOS battery died. It is a CR2016 3v Battery, I ordered 4 new CR2016 3v batteries off the internet, but they simply will not work. It will start up on power cable and I can eventually get into Windows with F1. But, even after leaving it on power for a whole day, the CMOS does not seem to retain the settings (ie. because the CMOS battery is not working). I have another XPS 18 (an i7) with an original CMOS Battery. When I put that into the XPS 18 (i5) all is ok. But when I put one of the new CR2016 3v Batteries that I ordered off the internet back into the XPS 18 (i5) and F1 in to the operating system and leave it on all day, as soon as I remove the power cord, replace the power cord and start it up, it goes into the CMOS message where I then have to press F1 to start up the OS. This means, of course, that the CMOS is empty and has not stored the settings. ie. none of the 4 new CR2016 3v CMOS batteries I bought seem to work.

What can I do? I do not seem to be able to contact and get help from Dell? I cannot seem to find "original" XPS 18 CMOS batteries on Ebay. Has anybody in the Dell community had this problem and found a solution? If so, I would be very grateful.