OK so I bought 4 different battery management systems as in the picture. I want to know which components would be responsible for protecting the batteries from discharging below the minimum voltage.
I know the green board with the red X under it (3rd left to right) does not have the protection circuit because the manufacturer told me so.
I think the blue board with the blue checkmark (2nd left to right) does have it because I've had it connected in my circuit for a while and they've never gone under.
The one in the bag should have it and the ones on the far right (3x) might not.
Could someone tell me if and which of the components are present on the boards are responsible for that protection? I'm guessing it would be opamp, right?