Super simple question. I am new to electronics and have to connect 4 12V lead-acid batteries in series. Once I connect the negative terminals of each battery to the positive terminals of the others, can I treat the whole battery system as a 'single' battery? That is, when connecting this system to the load should I follow the standard convention to connect the positive terminal first, then connect the negative terminal?
The main reason I am asking is that I saw a more experienced person first connect the negative terminal of the battery to the negative bus, then continue to just arbitrarily make connections until finally, they connected the positive terminal of the series system to the load. It seemed like they were not following any sort of safety convention, but were quite confident about their approach.
I know this is fairly harmless, but working with batteries has always freaked me out a little bit. Any advice on this would be helpful!