My battery light came on last night, and I lost my power steering on the next startup, in My R53 S.
I barley made it home. headlights were nearly nonextant, barley any light from them at all, like my battery was going dead.
Woke up this morning car started right up battery read 14v ? so I started to charge it (Schumacher charger) and the charge percentage started to go up (slow 6amp charge). at about 35% charged according to the charger, I checked the voltage. it was at 16v.
At that point I pulled the battery out got it tested, it was high but seemed good, the guy at Advanced said definitely my voltage regulator inside my alternator.
So do you think I need a new Battery or alternator or both>?

I tested the battery myself with a load tester and the battery seemed fine, passed
What should I check or replace first?
battery is out of the car for now until volts drop.
grounding strap is in place. right side upper engine mount.