Any novice mechanic should own a least a voltmeter, if not a multimeter. They can be had cheap.
You simply turn on the voltmeter, and set it to measure whatever type of voltage you are looking for (AC or DC). The voltage you are looking for is DC, so you set it to meaure DC voltage (signified visually by a solid line and a dotted line next to it, instead of a wavy line indicating AC).
Once within the DC set of choices, you choose the RANGE of voltage that you will be measuring (IE UP TO 1 volt, 10 volts, 100 volts, etc) You are looking for up to 14.7 so the next highest choice above 14.7...
Then simply place the probes on the battery terminals (red for positive, and black for negative).
Read the screen, then do as I suggested with revving the car, and also measuring the off-voltage.
Ray
