While I was reading a physics textbook, I've seen something unclear, which is about ΔV. What does this book actually mean by ΔV? It seems like it is potential difference, right? However, the thing I'm trying to get is why it is potential difference, assume that there are two batteries connected in series or parallel, How should we analyze the circuit? Honestly, I didn't see anything related to parallel/series batteries, Why? On other hand, it should've explained what to do when there are batteries connected in series or parallel. What am I missing?
Wishing My Kindest Regards!