home security battery ??

[porshapower@xxxxxxxxx (:\) :\))]

Hello:)   I have a DSC (DIGITAL SECURITY CONTROLS) alarm system in the
home.  I have found their website online but they wont return my email.
Recently a "yellow" trouble light came on which I checked the code in
the manual and it says it is the battery.   Where on earth is the
battery so I can change it??  Manual does not say.  I tried prying the
keypad but didnt seem to come apart.  My model is a PC1500.  Thanks for
the help in advance!! :)