You can disable BSM using Forscan. Be in the Service functions menu > BdyCM BSM reset.
However, in our cars the battery type is specified by default AGM 80Ah 700CCA. But the AGM battery charging algorithm is different from the acid battery charging. This is how we get the wrong charge when using acid batteries.
I assume this setting as built BCM 726-04-01.
If we can change the battery type, all problems will be solved.