Before patch magic battery files to able to work with Slim, you can just copy all files (dirs /kd, /registry and file UPDATE.PBP) from memory stick to your computer. (may be in folder "PSP1000PANDORA").
After patch magic battery files do the same work - copy all files to your computer (may be to PSP2000PANDORA).
After all - just replace files on memory stick with files on your computer, when you going to flashing PSP or PSP-Slim. (but don't format your magic memory stick - you'll lose your IPL on it, and you'll forced to recreate Pandora from begining).