I have a Sprinter RV (Pleasure-Way) with two lithium batteries in parallel (can be considered one for purposes here), with no shunt or other way to accurately know state of charge. The batteries can charge through two separate paths, either from the engine alternator or via combination of solar controller and/or AC from shore or generator. (Discharge occurs only through the latter path.) Bat returns are connected to chassis ground. I'd like to add a shunt, but these two charge paths do not converge.
Is it feasible to employ two shunts, located in each charge path, and then sum their outputs into one BMV? A (possibly isolated) summing circuit seems needed, but that could be a simple op amp based device. Thanks in advance and sorry if this question is already posted elsewhere.
