Hybrid Battery

[cat350]

I gargae my car and use it infrequently in the winter months. It could be idle for 3 weeks. I've been told that the battery will die and the car won't start under these circumstances, especially where the key fob is left on the dashboard---which is common in garages. This has happened to a neighbor with a Lexus IS hybrid. This doesn't seem right to me.

[SW03ES]

The issue is not the hybrid battery, the issue is the 12V battery that is used to start the car.

If you leave it in the garage with the smart key on the dash, I would be surprised if it didn't go dead while you were gone. Basically when the key is in the car the car is in "ready to start mode" and the car is constantly communicating with the key, preparing for you to push the start button. This has nothing to do with it being a hybrid, this would happen in any car with a keyless start and entry system. That constant communication will kill the battery over 3 weeks.

In general leaving your keys in your car is never a good idea anyways, even in a garage. If someone breaks into the garage (garage door openers are rolling coded and do spontaneously open sometimes, and sometimes respond to other people's openers) and someone steals your car for instance...your insurance company won't pay because you failed to properly secure your vehicle.

Best practice is to keep the keys inside the house.