A series connection or circuit is used to increase total potential (colloquially known as voltage). In a series circuit, the capacity remains the same. To provide an example: if 30 batteries rated for 12.8 V at 100Ah are connected in series, this creates a battery system capable of supplying 384 V at 100Ah. When creating a series circuit, it is also very important that all connecting cables have the same length and thickness. In a series circuit, the positive terminal of one battery is connected to the negative terminal of another. The remaining unconnected positive (+) and negative (-) terminals are then connected to the device one intends to power. These terminals are also indicated as the “end” positive and “end” negative terminals.\r\rBatteries with different capacities (Ah) and voltages (V) may never be connected to each other in series. We also advise that when batteries of the same voltage and capacity rating are assembled into a single battery system, they be of the same brand and production series and preferably of the same production date.