I bought a Balmar Digital Duo Charge batter-to-battery charger and want to use it as shown in the attached schematic. The switch S2 is used to put the 2 batteries in parallel, in case the starter battery B2 has not enough power. An electronic wizard pointed out to me, that S2 will shorten input and output lead of the B2B charger, which will probably not like this.
I could not find anything on Balmars home page about this problem. Does anybody know if this can cause a problem? If yes, I would have to install a 3rd switch, which I would not like.