this has been asked before with no satisfactory and definitive answer:
can a 12V PV maintain a 24V bank?
what does one need to do in order to get this to work? connect the battery first, to establish V being 24V, and then attach the 12V PV to show the input current? is there any built-in buck boost in the BlueSolar 75/15?
I have read that a BlueSolar MPPT 75/15 will only start to charge when the PV output V is 0.5V more than the current battery bank V, then stop when it is under 0.1V, but does that mean that it absolutely will not work as 12/24V dependent/congruent system?
will it work from 24V PV to 12V bank? why not versa vica?