Use volt meter to check 12 volt battery charge level?

With your volt meter, touch the positive battery with the red wire and black to ground (neg, ) on the battery. With the engine off you should have a reading of anywhere from 12.2 to 12.6 volts. That is good. With the engine running at high rev's you should have a reading of any where from 14 to 14.5. When you charge the battery with a 2 amp charger it will take several days and the charge level will go up to 14.5 or so volts.