I was driving my 2020 F-type and “battery system fault” light came on. After a couple of more miles, other warning lights came on and battery went dead just as I got home. I have it charging now. Original battery as far as I know. Any ides where to start?

 

Take the battery to an auto supply store to be tested. After 3 years, batteries are on borrowed time.

 

Sounds more like an issue with the charging circuitry, maybe a dodgy earth. My battery has been on "borrowed time" for 4 years now, and still seems to be going strong.

 

Yep, as I have said many times I am still on the original battery which will be 10 years old in September, so hooey to borrowed time after 3 or 4 years!
The secret is to regularly hook up a battery maintainer/tender/trickle charger.
Also AGM batteries make a difference compared to the older flooded cell batteries, from all reports they last much longer even without using a maintainer.
On all my previous cars including a 2010 XFS and 2010 XFR yes the battery started to show signs of weakness after around four years old so I replaced it once it got to that stage, but that was before I learned about battery maintainers which I can largely thank this forum for.

 

I had the same issue a year and a half ago. Turned out to be a bad alternator. My extended warranty, covered it fortunately.