When sitting still and car is not running, the battery will drain in a matter of minutes and requires a boost to start.

It happened again to my wife this week when she was waiting for my boy to finish a class.

Sitting in the car, lsitening to tunes but not running, the battery goes flat.

Dearler checked battery and say it's ok.

Ideas?

 

Should have specifies it's a 2005 RX330 with 85,000 miles.

 

Would take it to another shop, perhaps an Advance Auto Parts, AutoZone, or Costco, where they will check your battery and your vehicle's charging system for free. Just running the radio should not be enough to drain a good battery.

 

Seems to be the battery is on it's way out, maybe a cell is bad.
With the engine on, the alternator supplies enough current for everything to function.
Engine off you're using battery power only, while it might not seem like just the radio alone would drain it, the battery doesn't have enough volts or amps to turn the starter.
Have it load tested at a local auto store as previously posted (usually for free) they'll even replace it. Then you'll need to have the power windows and sunroof reinitialized for auto function
Surprised the dealer didn't jump on the chance to replace it!

 

Ditto on the BM auto stores, they will diagnose of battery or the Alt.