Could it be the sony PCGA-BP2V battery on my laptop cut short

Question:My 3 year old sony PCGA-BP2V battery is continually losing an hour at a time on the clock. The time zone has been corrected, but I'm still losing time. It was suggested that it could be my internal battery. I've been experiencing this problem for a couple of months now. Does this mean it'll have to be replaced and, if so,where have the battery ? Answer:more than likely the cmos battery is dying. This is different from the big battery. The laptop has to be torn open to get to the Cmos battery.and like replace the battery with Dell Latitude D800 battery , Dell Latitude D810 battery , Dell Latitude D820 battery , Dell Latitude X300 battery , Dell Latitude X200 battery , Dell Latitude D500 battery , Or sony VGP-BPS3 battery , sony PCGA-BP71 battery , sony VGP-BPL5A battery , sony VGP-BPS5A battery , sony VGP-BPS5 battery , sony PCGA-BP2NY battery.and you can scan website:http://www.mainec.com/laptop-battery/ and http://www.new-laptop-battery.com/ wish you can buy a good battery .