Went to start the car this morning for the wife and it was dead. Measured 3 volts on the battery. Nothing lit up inside the cabin. It took about 15 mins or so to get it to start off our other car. I tried it every 5 minutes or so and the car finally turned over. The starter could barely crank initially but as the charge built up it came alive. I let the car run for 30 mins, shut it off and it restarted without issues. I went to the gym where the car sat for about 2 hours and it started right up again. Came home and washed and detailed the car. It sat for about 3-4 hours and started right up again. What could have happened? No light were left on and no doors open.