Looking for some clarification on the proper steps i should take to add 2 additional 6V batteries to our current power bank which is presently 2 - 6v batteries. I am adding same brand and size batteries, and will be putting them in series / parallel, but what i want to know is do i simply just turn off the inverter so that the system is not running, or is there something else i need to do before i start to add the wiring between the batteries? thanks.