[Pops944]

Clean your battery terminals/cable ends with baking soda and rinse well. After the terminals are tightened on the posts, apply the KY gel or Vaseline; this will protect the cable ends and the terminals from moisture that causes the corrosion. 12 volts on the battery before starting is okay, and will drop to about 9-9 1/2 volts while cranking. If it drops to about 6 volts you have a bad cell that could be as simple as low electrolyte or in need of a good deep charge. If the voltage drops below that you need a new battery. The next time it doesn't crank like this if the voltage at the battery isn't dropping to indicate drain for starting try using a jumper cable to jumper the ground post to the engine. If the car starts, back to ground hunting.