My THC is in the shop. I found it dead in the morning the other day. This is twice occuring in a week. The first time they didnt find anything, they thought maybe i drained the battery by leaving something on. They recharged the battery, left it overnight to inspect. It was fine. I drove it. Then this weekend the same thing happened. Since the weather is getting cold, i used my defrost on both occasions. They think the defrost relay is draining the battery. Has this happened to anyone?