Using this cable is super easy. First, identify the red wire for power and the black wire for ground. When you want to connect a board in series, like the LC709203F Stemma QT battery gauge, just plug the JST PH 2 - pin plugs at both ends of the cable into the appropriate ports. Since it's an A - A cable, you don't have to worry about the polarity. You can even flip the cable around, and it'll still connect correctly. As for maintenance, keep it away from sharp objects to avoid cutting the wires. Also, don't expose it to extreme temperatures, as this could damage the insulation. If it gets dirty, you can gently wipe it with a dry cloth.