Car jumper cables, even though they have a large ampacity, do not need to have a high voltage rating because the vast majority of vehicles use a 12V starting battery. The type of insulation on a wire is directly related to its voltage rating. The voltage rating of a wire is similar to the pressure rating of a hydraulic hose. When it gets hot the insulation starts to melt, and if 2 different wires touch they can create a spark and start a fire. If too much current flows in a wire, the heat cannot be dissipated into the air fast enough and the wire gets hot. Because resistance in wires is dissipated as heat, you would want as large of wires as practicable. The current carrying capacity of a wire is called its ampacity. the total available power is 24V x 200A = 4800W.the total available current is 2 x 100A = 200A.Four 12V, 100A batteries in series/parallel is called a 2S2P configuration.the total available power is 12V x 400A = 4800W.the total available current is 4 x 100A = 400A.Four 12V, 100A batteries in parallel is called a 4P or 1S4P configuration.the total available power is 48V x 100A = 4800W.the total available current is 1 x 100A = 100A.
Four 12V batteries rated for 1800Wh each will give a total of 6000Wh of energy storage whether they are all connected in parallel, all connected in series, or a combination of both. Similar to the power example above, for the purposes of energy storage, it does not matter how the batteries are configured. 1800 x 1 = 100 x 18, but will use it at different rates (power). They both will use the same amount of energy, i.e. By the same token, you could use a smaller 100W motor for 18 hours. If the total battery capacity is 1800Wh (Watt-hours), then, in theory, you can use an 1800W (~2.5hp) motor for 1 hour before the battery is drained. Battery capacity is a measure of the total energy needed to charge the batteries, or the total energy available when they are fully charged. While it is very easy to confuse power and energy, and often times the 2 words are used interchangeably, they are not the same thing.