Voltage

volts for short. 

The upper case letter V is used to represent voltage on a Digital Multimeter (DMM).  

If you are confused between the E and the V, you are not alone; they are often mistaken as meaning the same thing.  To clarify the difference between them lets use a baking example.  If a cookie recipe called for 2 cups of flour you would never confuse the measuring cup and the flour as being the same thing.  The flour is what you are measuring; the cup is unit of the measurement.

Now let's compare 2 cups of flour to E and V.  The E is the same as the flour; it is what you are measuring.  The V is the same thing as the measuring cup; it is the unit of measurement for electromotive force.  It would be correct and proper when measuring the electromotive force of an automotive battery to say that you have measured 12 volts of electromotive force. 

Note: 42-Volt systems are beginning to appear on new (2004 and newer) automobiles.  A 42-Volt system uses three 12.6 volt batteries in series with each other for a total of 37.8 volts.  When the engine is running and the charging system is functioning, the system voltage will be approximately 42 volts. 

Eventually every vehicle will use 42-Volt systems rather than 12-Volt systems.  42-Volt systems allow wire sizes to be smaller and lighter.  Charging systems will not have to work as hard because a 42-Volt system does not use as much current as a 12-Volt system does.  These benefits will help to reduce emissions and to improve fuel economy.

Next, let's go back to the ions in containers example from earlier in this assignment.  We have a container full of positive ions and a container full of negative ions. There is a great amount of electrical pressure inside the containers caused by like charged ions being forced to be together.