I've found such batteries to be old off the shelf. Don't buy from the same place!
I have an Acer Aspire 5920 laptop with MS Vista, SP2. I have been experiencing problems with the system clock. It lags at times and if I remove the main battery, the date/time goes back to April 2007. I was told before that it was the CMOS battery so I replaced it. Now it's doing the same thing again. Would anyone be able to give me some advice. Thanks Karen