I have issues like that for my mom's glucose monitor. I can't dally, but if I replace a battery quickly one at a time, I don't have to re-program. Time and date mostly. It uses two AAA batteries.

 

Good news is that I can always pull it down off the wall and replace the electrolytic with something better. Perhaps Ceramic. But I really don't know which is best, better or just good enough. For now I've my proof of concept. 3300 µF works for what I want.