Bms cl 100

I am only getting 15% charge turned off of my engine alternator. I’m wondering whether or not there is something wrong with the alternator or BMS

What voltage is coming from the alternator?
The BMS needs a voltage difference between alternator and lithium battery.
With a higher difference you get a bigger current.

12 volts from the alternator

I don’t think that is the exact voltage coming from the alternator.
What alternator/starter voltage does the BMS show with the motor running?