2008 Toyota Prius would not start without jump. No codes.

This has happened twice now. The car will be completely dead requiring a jump start. The second the cables are attached the prius restarts. Checked the 12 V bat and it said "good, needs charging". OBD2 shows no codes. the car was on the second bar of low gas. i dont think i left any lights on. Checked common fuses on right of box. Im not sure if its a low gas problem because after a jump it ran just fine. even restarted. From what i looked up the common issues are inverter water pump or Dc/Dc converter. but both those would pop a OBD code. Checked the hybrid battey and its above the wattage or voltage.