Does it drain the 12V battery to leave a fob inside a Highlander Hybrid that is entirely powered OFF?

I drive a 2009 HH and can't tell you how many times in the past 2 months that I have come outside to a dead car battery. Original everything - nothing has been replaced. No other problems with HH except the 12V.

Last week I took the HH to Toyota for a battery check. The test results showed the battery was "OK" - about 50% life left in it. They did not recommend that I replace it. BUT, i did drive the car 20 miles on the highway to get to the Toyota dealership -- could the readings have been wrong given that the car had just been run hard?

I am diligent in making sure that nothing else is running when I power off the car. No interior lights. No doors ajar. Nothing.

I have however found that the car battery is dead on the mornings after i've left the fob inside the car all night long.

The only thing I can figure is that by leaving the fob inside the car at night, the 12V battery is drawing a very slight undectable charge that is draining the 12V (which is already getting old and in a weakened state) -- is that even physically possible? If so, I guess I'll have to keep the fob with me at all times.

Obviously we live in a very safe neighborhood so I don't worry that anyone will steal the car in the middle of the night. But i worry that i'm wearing thin my welcome with neighbors to CONSTANTLY ask for jumpstarts.

Thanks for any advice you can provide.

 

http://www.toyotanation.com/forum/12...ain-issue.html

 

Two things:

1) Don't leave the fob in the car (vehicle's onboard computers "wake up" with fob nearby)
2) Anything below 60% battery life is toast, you should replace it.

You can just hook up the vehicle to a smart charger nightly but that gets to be a bit tedious after a while.