Q: Battery replaced, but car still dies

"A couple of months ago, the battery in my car was exhausted, so I replaced it. Since then, sometimes when I start the car, it is dead completely. I questioned myself if I had left something on, until it appeared again 2 days later. This is what is occurring:

--The car is totally fine and then goes to totally dead as soon as it is turned off. --The seat doesn't go to the exit position and the steering wheel won't move. If you try to start it, there’s no life at all. No noises, no lights - nothing at all!

I used a meter to test the battery and it read 11.9 volts. Here are some more details to note:

--If i put jumper cables on the battery and very quickly touch opposite ends, this corrects the problem and the car starts immediately with no problems at all. --A different time, the car was completely dead when I tried to start it, so I raised the hood and Immediately, as soon as the latch released the lights came on and I had Full power and it started right up! What is causing these problems?"