When I turn my hybrid off, the hybrid engine will start up 10 seconds later, and not turn off until the battery goes dead. Which means I have to boost it every time.
What does your dealership says about the problem.
To me, very odd the gas engine runs until the battery dies, but can be restarted with a jump.
By “hybrid engine” I presume you mean the car’s gasoline engine. So it starts up and idles for no apparent reason when you turn the car off, like when you park and get out? One idea …
The car’s 12 volt battery may be on its last legs. If this is the case, the computer probably knows the 12 volt battery is nearly dead , and is running the gasoline engine (and the alternator) to charge it, but it won’t hold a charge and it eventually goes dead anyway, even while being charged. Or the alternator isn’t properly charging the 12 volt battery. Suggest to ask your shop test both the 12 volt battery and the alternator. If the 12 volt battery is original to the car, it almost certainly needs to be replace as it is 8 years old.
Disclaimer, I’m a diy’er, no personal experience w/your car’s configuration.
The battery has probably failed however there is no alternator to test and the engine does not need to be running to charge the battery. The auxiliary battery (12 volt) is charged when the ignition is in the “Ready” mode via the DC/DC converter.
How old is the 12v battery?
Another one for probably the low voltage (12 volt) battery has failed…