Lifetime of the batteries is generally linked to throughput (full charge/discharge cycles). For batteries that go through one charge and discharge a day, this results in the battery energy storage capacity being around 60-70% at the end of 10 years [1].

For this Tesla battery (frequency support), the battery isn't required to fully charge/discharge every day, and instead only charges/discharges in response to over/underfrequency events on the power grid (you can see its current status on their website [2]). Without following the day-to-day operation of the battery, you could estimate the lifespan of the battery will be 10 years+.

[1] https://vectorwebstoreprd.blob.core.windows.net/blob/vector/...

[2] https://hornsdalepowerreserve.com.au/