Car dies after turning engine off but then comes back to lif

[Taseen]

Recently been having this issue. I drive somewhere and all goes normally. When I park up and turn the engine off, the car immediately dies - as in no electricity whatsoever. But after a minute or so, it comes back and all is normal. I’m guessing my Battery has gone bad or some connection has corroded but wanted to see if anyone has any better idea of what the issue is.

For better context, the first time it happened it only took about 5 seconds for power to be restored. It seems that every time it happens it takes longer to come back to life.

My car is being serviced at Lexus on Monday so I’ll just ask them to give it a check.

Car is a 2006 IS250.