Q: Car won't start and the cd player ejected a cd without me touching it. What's going on?

Hi and thanks for contacting Your Mechanic. You had mentioned that your battery had 10.1 volts at the time and said that is what the battery usually has. A fully charged battery will have 12.6 volts, a 75% charged battery will have 12.4 volts, a 50% charged battery will have 12.2 volts, and a 25 % charged battery will have 12.0 volts. Any thing under 12.0 volts is considered a dead battery (a battery without a charge). This will cause lots of problems with the vehicle. The computer in vehicles of 2009 and newer require a minimum of 11.5 volts to make the computer function. A computer will keep its memory with a minimum of 9.6 volts, but it will not function. I recommend replacing charging the battery to a full charge and rechecking your symptoms that are occurring. Now, if the vehicle was driven around with a low charged battery, it is possible that the battery could have a bad burned cell which will cause the battery to drain back down fast. In this case, the battery should be replaced. Check the alternator for operation when the engine is running and see if there is a voltage of 13.5 to 14.7. Then turn on the head lights with the brights on and operate all of the windows at the same time. Check to see if the lights dim out. If the lights dim out, then the alternator may not be producing enough amperage and it may need to be replaced. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from Your Mechanic, that can assist you with your low voltage battery and electrical issue within the cab.