Suggestion: Assume a battery lasts for 10 years. If the cost is $20,000, then put $2000 per year into your battery fund (adjust these numbers to match your own expectations). If you buy used, add the $2000 per year at the outset for existing age (if you can't afford it, you may be buying outside your capacity and may regret it later).
That should change an issue that is steeped in fear, emotional, and uncertain, into a simple economic matter.
You might consider putting it into TSLA stock. A friend who passed on FSD 4 years ago and put the cost into TSLA ended up essentially with a free car.
It raises the question of whether TSLA might be a good hedge against future price increases of Tesla vehicles for an intended future buyer. Today's $800 per share may be an excellent entry point. My wife has her eye on an X in the next few years and we're doing just this. My target scenario is that we buy periodically as it reaches a low of $500, and recovers to $1000 in a couple years, and end up with a very discounted car. Of course, there are taxes on the gains (wish it could be a like-kind exchange).
But that's off topic. I note that those who have a car as a business vehicle can expense the expensive battery replacement.