Dell XPS 8700 CMOS BIOS RTC Battery replacement help!

I'm going on my third year of owning my dell XPS 8700 desktop and recently- for about two months- sometimes when I turn it on, I will get one initial beep and five beeps after. I went to the forums and figured out it was a problem with my CMOS battery. I did not want to have to reset my BIOS every time I booted up my 8700 so I decided to buy a new CMOS battery. Yet I cannot find one. all that is being suggested are  CMOS batteries for the Dell XPS 8700 laptop or random case enclosed CMOS batteries with wires coming out for the 9000 series. 

Please let me know where I can find a replacement CMOS battery for my 8700 Desktop- must be an American site or a site that ships to America-. Thanks!