I go a different direction than others. I go buy a reasonably priced (under $150) battery that meets our specifications and size.
Then, at 48 months, I buy a new battery.

And this is not just what I do with the Crossfire, my Ford Ranger gets the same treatment.. I do this for several reasons that all have to do with:

1) Being stranded by a bad battery.
2) Loosing a seat belt module due to a weak battery.
3) Reading all the stories here and on Facebook over the last thirteen years about how someone fought an issue with a Crossfire, only to replace the battery and see issues go away.
4) Remembering how, in 2010, I had a company Dodge Durango and one day, it would crank and start, when I let go of the key, the engine died. It refused to start. Got towed to my boss's favorite garage. They spend over an hour, could not start it. Some old guy said, 'change the battery'. After some time, they tried that. Durango started and ran fine!

The message I got: A battery every four years is cheaper than a tow, it can eliminate being stranded, and it might just save one of those expensive modules in the car.

Remember, your battery is:
Your car's secondary voltage regulator
Your car's primary ripple filter (ripple from the three-phase output of the alternator)
Your car's noise (electrical noise) filter
Finally, the battery provides the capacitance needed to filter out the spike of the starter (and other large motors) from being fed into the car's modules.

Providing 300 amps to turn the engine over is just PART of the battery's job. A weakened battery can still spin the engine over, but not be able to do as effective of a job at the tasks above as when it's new, strong and healthy.