A 6V battery consistently supplies 6 volts to any connected circuit components. If a lamp in the circuit has a voltage drop of 3 volts per coulomb, it utilizes half of the battery's voltage. The remaining 3 volts are available for other components in the circuit. The battery's capacity is measured in ampere-hours, which can be converted to coulombs for further understanding. Thus, the battery's voltage output is independent of the specific needs of individual components, as it maintains a constant 6 volts.