My battery died after 5 years and 1 month. My other car needed it's battery replaced in the fall around the 5 year mark. That time frame seems to be about average for my cars over the years, except for the original factory batteries which seem to fail in about 4 years.
Fortunately it was while temps were in the low 30's so it wasn't bad putting in a new one. Temps are supposed to go down to the teens and single digits in lower NYS for awhile. I would not want to be working on the car at those temperatures. Charging system checked and working well.

 

Five years has been the battery life on my ES350 and RX350, both owned since new. When they go, there is no fooling around, get a new one.

 

I use good 1.5-2amp battery charger-maintainers on all my four vehicles, that sit for days-weeks-months between uses; the sole exception is my wife's '14 ES350, which never goes more than two days sitting idle (besides, she NEVER remembers to unplug the charger before driving off, so when she needs her pickup, I must unplug it for her...women!).

The four vehicles always on-charge are old: a '98 GMC, '04 Chevy 2500HD, '09 Chevy HHR Panel, and my personal '01 BMW X5 E53 (wife not allowed to touch it, as I'm prohibited from driving her Lexus); over the years I've seen a pattern concerning the relationship of the number of "computer modules" in each vehicle, and the battery life each gets.

The '98 GMC has the least modules and gets the longest battery life, between 8-11 years, the '04 2500HD has more modules (but not many, since it is a basic Work Truck model), so its' batteries last slightly less, at 5-8 years, the '09 HHR Panel is also a basic model (with the smallest engine), but though it has an extra module or two, the batteries have lasted almost as long as the GMC's, at 7-10 years, and the '01 BMW X5, with 13 modules active, has the shortest battery life, at 3.5-5 years (possibly skewed, due to constant tinkering with it...it's a project car).

The battery charger-maintainers have been rotated amongst the vehicles, so their charging differences aren't a factor in their effect on battery life. I've been using them on the GMC and 2500HD since '07, the HHR since new in '09, and the BMW since May '21, when I got it (the battery then installed last 3.5 years, but the two previous owners reported up to 5 years on previous batteries). All batteries used were of the recommended (or greater) capacity, and were AC Delco, O'Reilly;s Super-Start, Autozone's Duralast Gold, Walmart's Everstart, and Sam's Club's Duracell (on the BMW).

My conclusion is that newer vehicles with more modules installed, have higher voltage requirements, and thus, draw down their batteries more.

 

Put your battery charging cable through the keyring on your wife's keys when plugging it in.

Problem solved.