Before you give up, consider swapping out the electronics module (the oblong plastic piece you see when you remove the inside cover) with electronics for BE469ZP, but only if you have a C-7, which can do S2 security (1/3 packets of S0). I was seeing similar short battery life on my two BE469, until I replaced my modules with BE469ZP. Batteries are now 98% after just over 6 months:
I’m expecting well over a year between battery replacements. I’m very happy after changing the modules for Z-Wave Plus ones.
You can get them on eBay, all BE469ZP modules are the same, regardless of lock model. Replace with 3 screws.
Occasionally you can find the inside-door piece sold separately from touchpad, or find one with broken touchpad. Just watch out for early firmware versions. One of mine is 0.11.0, other is 0.10.9, both work fine.
One was $39, other was $49. If you get one with just inside part, make sure you get the door mounting plate, or at least, as I did on one of mine, a photo of the sticker on the door side of the mounting plate, because that’s where the S2 DSK key is, needed for S2 inclusion.