Hi! I'm trying to install the BMV-700 for my house batteries on my sailboat. The instructions say to install the shunt between the battery negative and and system ground. I have 3 house batteries connected serially (that I want to monitor) and one starter battery (I don't want to monitor). My problem is that the negative from the house battery is connected to the negative of the started battery before it goes to system ground. And my question is, is it OK to install the shunt between the house battery's negative and the starter battery's one? (See also photo attached, although not super clear). Thank you!!