Likely longer than 5 years with lithium AA.
If you still have regular battery holder fine. Put them in with a sticker use lithium only and the month/year you installed and call me in about 7 years when you will need to change again.
Lithium are the same battery that backs up all computer BIOS settings.
You don't ever change them right?? Not for like 7 or more years. Same thing with pins ram. The spec datasheets are a bit broad but you are in the range of 50micro amps current. Most meters do not even measure that low.