Proactively Replace 12V Battery?

I just replaced the original 12V in my 2017 a couple of months ago, and the car now spends most of its time in Florida, in a climate that is probably less conducive to long battery life than your more moderate climate. It is surprising to me that you needed to replace your battery as early as you did. Was there a specific reason your original battery only lasted 3 years or so? I doubt that you are going to get "stranded" somewhere, regardless. That would mean that the battery would suddenly refuse to fire up the computers after it had been capable of getting you to a remote location in the recent past. The more likely scenario, in my opinion, would be that it would refuse to do its job after the car had been sitting undriven for a few days in your driveway, so you would not be "stranded" in the usual sense. Mine had been giving me warning signs for a few weeks before I left the car sitting in our Florida driveway over the summer. When I returned in the fall, the first thing I did was put a charger on it overnight, but by that time it was dead as a doornail. Luckily, I was able to find a replacement within walking distance, although the guy in the auto parts store couldn't quite believe that I was actually going to put it under my arm and carry it home. ;-). I drove the car back the next day to get my cash rebate for turning in the old one.

 

One of those rechargeable 12V starter packs might be a better idea. Peace of mind anyway. If your battery does fail, it could get you going again. I replaced mine after it failed one of those periodic dealer service stress tests, after which I went home and put it on my battery conditioner/tester and it failed there too. Replaced it myself with another Toyota TrueStart.

 

I’d instead spend money an an electronic load tester and suitable smart charger. Take mystery out of the equation. If I was shopping today:

Tester

Charger

 

+1 ^ A quality testing and charging kit is what every Prius owner should have. My comment was directed toward a person that already knows they are limping along with a failing battery and maybe saving up for the inevitable expense.

 

IMHO; I wouldn't, but I own a jump pack and battery charger. I've had lead acid batteries go 10+ years without fail. When they get that old, one good jolt will kill them. Any auto parts store will test them for free, so I don't see the point of proactively replacing it - because you can accidentally leave the headlamps on and kill it the next day.
Whenever I go on a long trip, outside my commute - I throw the spare tire and jump pack into the car and check all the vital fluids..

Just my 2-cents....

 

You would be spending (and probably wasting) a lot of money that would be completely unnecessary. For a lot less money ($50 right now on Amazon) you can get a very good battery tester (TOPDON BT100) that will let you know the battery condition now and in the future.
Dumping a lead acid battery because you think it might go bad with no indication that it is going bad isn’t necessarily being “proactive” (at least, not in a responsible way). Getting it tested to determine the battery’s state of health is a much more responsible proactive approach.
As far as getting a charger or a jump kit, again why not test the battery periodically? In 57 years of driving and caring for personal vehicles, I have never had a battery fail me that I was testing periodically. I have, however, bailed friends out who’s battery failed them because they kept charging their batteries but never tested them.