I've built the 48v Lifepo4 battery system from 16 cells in series. But all my knowledge has come from the internet not college, they do say ignorance is bliss!
LiPo is a whole new kettle of fish! There are a couple people on here who have done SBC/arduino controllers and such for them, it's all way over my head.
But I do know that they need to be balanced, and charged correctly, or they tend to get a bit explodey...
As to your original query, I don't know the SOMs particularly, but an -alternator-
does require a field/reference voltage. 22V should be more than enough to excite the field and create output.
The things to check then would be your diode bridge/rectifier. And for any shorts to ground.
Your batteries could also be poked, with low internal resistance.
A -generator- should output voltage all the time, again you can check for shorts to ground, particularly clean up the commutator and slip rings.