ACT produce an excellent tester, too expensive if this is a one off. If you switch your mains off to the panel, and it dosent have an NVM you will lose all the programming. Most modern panels do have an NVM chip though, Best and easiest way, is take the battery out and connect it to a 12vdc lamp, if it stays lit brightly for 3/4 mins it should be ok for a wile.
John
February 2009