Quoted from loren3233:
Do the newer Stern games have batteries that need to be changed out every year?
No. The newer Sterns using S.A.M. Systems boards which have a single CR2430 Lithium coin cell that should last 10 years without leaking. The change over from White Star to S.A.M. took place in 2006 and 2007. I have seen 20 year old CR2430 cells that are still holding voltage and not leaking.
The White Star CPU boards took 3 AA batteries and need to be changed every year or two.
If you are not sure, look up the machine on ipdb which tells which System board your ss pinball machine uses.