I had a Takata airbag replacement this week and during the repair (mobile service at my home) the tech noticed the replace battery warning light was on. This will be the 3rd battery in about 5 years and 105K miles. I got about 2 years out of the last one. Interestingly, the tech said Tesla is using a new tech in these now, called it a carbon nano battery instead of the exide ones they've been using. Cost was $150 plus $70 labor. I chatted with the tech about how I considered doing the swap myself but it looked like a pain to change these on the older generation cars like mine. He agreed and also noted that with the new battery type, there had to be a modification to the charging algorithm so you couldn't just swap in the new type battery yourself without some input/setup from Tesla.
Part number:
Battery, 12V, DCS33-UNCR, MS (1083774- 1 150.00 00-A)