Connecting B300 and B300K

I have an AC300 and two B300 (about 2 years). I purchased the same product in August 2024. I was not notified by Bluetti that the B300 was discontinued by email. There was an issue with emails that was my fault. Now their solution is to send me an AC300 with two B300K. My question is when I hook the two power head up to a Fusion Box. How will each power head understand what or how much each battery will need to complete charge cycle.
Question 2, can I hook B300 and B300K to same power head?