Bri2490

I have had a Lexus RX400H for the past 5 years now and its such a great car. In the past month my Lexus RX400H has had a flat battery approx 4 times, if I jump start it everything is fine for the day. I had the battery checked out and my local garage said the battery is fine and I will need to take the car to an electronic expert as they believe something must be draining the power. Has anybody had anything similar as its getting a little annoying. Thanks Brian