Sounds like alternator is gone and I had exactly the same problem in FEB.

My battery was new, I was driving the car on the road and every electrical of it was draining the battery until it gone completely flat during my journey. I had to used a recovery truck

Alternator was certified dead when the car was sent to my mechanic, so ordered a new 90A with express service to HK from Burton which was quite expensive

https://www.burtonpower.com/genuine-...90-altyb4.html

I would have brought from Mike Rainbird if I knew they stock them as the one from Mike is 145A

http://www.randbmotorsport.co.uk/sho...?ProductID=389

Hope these information helps.