I recently started my car and backed out of my driveway, when I put the car into first gear it stopped running and it would start back up. I pushed it back into the drive way and waiting for about 5 minutes with the car off and no key in the ignition. I started the car back up but with more effort then normal . I tested the car by driving up the street and in second gear the car just stopped running again but this time it started right up. On my way back to the house the car stalled out again in 2nd gear.My battery is at 12.3V when the car is off and the info screen says it's ok. The lights , radio, etc. all work. What's happening ?