[FCS]

As the BMS will never let the battery volts go below 12.2 I think you can say that the generator is shot.

 

[FCS]

The alternator has probably failed due to excess current being drawn. Hence I would advise a high output one. I always am conscious of current I am drawing from mine, by that I mean shutting down certain systems when large loads are present, for example when in rain and cold weather with wipers, screen heat, headlights, etc. I shut down screen heat asap and rear window heat. At low engine rpm with high current drain the diodes in the generator will have less cooling and will get hot, which will reduce their life. If they go S/C you will have a big problem.
I would go for a 220A