I tried searching but could not find anything similar to my problem.
One fine morning I get into the car and bluetooth punk was acting weird, but I have had that problem before so I did not worry.
So I reach work and in the evening when I start the car I get "electrical consumers switched off" message. Although everything was working except that the steering wheel did not adjust to the correct position, but I was manually able to adjust it and bluetooth punk was again not working correctly.
I drive for 7 miles to reach home.
Next morning - I unlock the car, all electrical gadgets are working but the car would not start. It just did not crank. I tried it a couple of times and then got "ESP not available" error.

Is this just a dead battery? I had got both batteries replaced 2 years back with OEM batteries from dealer.

 

Could be but could also be charging system problem. I would recommend you do a full battery load test then charging system to find the problem. You need more data to answer the question of "battery"?

 

My wife's 2004 E320S with MB OEM bluetooth puck has now had its battery drain 3 times overnight after using the bluetooth to make a call. In all cases, my wife was driving while making the call and after she arrived home and turned the car completely off and removed the key, the COMAND unit turned on and started to act like a call was being made/in progress. Then in the morning, she finds the car's battery is dead and I have to charge it.

Is this a problem due to the phone handset or the puck itself?

 

I've noticed that Command is very aggressive about intercepting Bluetooth calls. Once as I was locking the car and I received a call and I suddendly heard the called INSIDE the car and I had to quickly get in the car to talk to the person who called. That said I don;t think the Bluetooth interface can consume that much power to completely drain the battery. Even it it comes to that, does the car not have a safeguard to cut off electronic consumers if the battery level reaches critical?