2006 BMW 330xi whose car-keys (the automatic one) is dead. I think its batteries are dead. What are my options?
I tried driving around to charge it but that didn't work.
You should be able to get the battery changed, either by an automotive locksmith or by your nearest BMW dealer. The batteries are usually standard coin cells, but I wouldn't try changing one without checking first as you might find it will need to be re-programmed afterwards.
Try a locksmith first as they will probably be a lot cheaper than BMW!
Not sure on your 330, but on my E39 the the battery in the key is automatically recharged when it is in the ignition. There's a clever induction system that keeps the battery charged.
Your battery may not work that way and may have died.
You may also have somehow gotten the car security system to "forget" your keys, so it isn't responding to them any longer. Some BMWs have a process where you can re-learn your keys without needing to take it to the $tealer.