Rep Power: 0

Yesterday I was driving during a rainstorm, on the freeway my engine shut off anything that was using power turned off for a sec or 2. I got home and checked the engine but everything seemed fine. The next morning I tried to start but nothing, no sound. The brake lights turned on at first but then died and didn't turn back on. I thought it must've been just a dead battery so I jumped, which worked great until I tried to turn the car headlights on, which killed the engine again. I tried again to jump it but this time when I closed the hood, the engine just stopped. I am pretty sure that the battery has power but can't start/ keep the engine running. Has anyone experienced this before, or something like it?

 
Rep Power: 224

Check the battery voltage with the engine running. You should see around 14V if the alternator is functioning.

 
Rep Power: 518

Battery is too weak to run the car by itself. Battery might still be good but it will need to be charged up.
After starting the engine, the alternator has to provide power to run the car and recharge the battery.
Alternator probably isn't working. Test accordingly.