If you have the flip-top battery compartment that pops out, they can be sticky until you open and close a few times. If it's really tight you may need to use something to pry it open (gently!) the first time or two. After that it'll be fine.
I had posted this about 10 years ago and I think the information is still accurate.
My 83' SR will barely accommodate a standard Duracell. You have to force it into the cavity.
The Duracell Pro Cell and Energizer are something like .020" smaller and fit like a glove.