Some of these sources can provide only minimal voltage and current and the high impedance input is designed to not load them excessively.

Some factory 32-volt radios used an electromechanical vibrator power supply to provide increased voltage.

If the source provides known voltage and current, such impedance can be calculated using Ohm's Law.

Also vehicles with an electronic engine management system will not start if the battery does not provide sufficient voltage to operate it.

Batteries also provide nearly constant voltage over their entire charge level, whereas the pressure varies greatly while using a pressure vessel from full to empty.

Two or more contactors may be used to provide reduced voltage starting of a motor.

During this time, the capacitor will discharge into the load, providing energy and voltage to it.

A 5 cell penny battery can last up to 6 1/2 hours providing minimal voltage.

A nickel cadmium cell provides less voltage than an alkaline cell, so the two types are not always interchangeable.

Back when oil prices were higher, Pacific Dunlop worked on a battery that would provide higher voltage more efficiently.