I have an E320. Took the car to a mechanic today who checked the battery and said it was charging correctly. I looked in the owner's manual and it mentions a broken poly-V-belt as a possible issue. Is this something I can check (is it visible)? If so, what does it look like? Just curious if this is really a battery issue or if the indicator light is malfunctioning.

 

If your poly-V-belt was broken your car would overheat (due to no fan), your battery wouldn't charge etc.
Depending on your year the belt is quite large and long and controls the fan behind the radiator. If its turning your belt isn't broken.
While I'm not a mechanic most if not all late model MBs only have one belt.
If your mechanic checked the battery he would be incompetent to not notice a broken belt.

 

Thanks for your comment. I took the car to a great Mercedes mechanic in Tampa. It was the second (front) battery under the hood that was bad.

 

I have a 2003 E-320 an the Battery light visit workshop red light comes on when starting. The battery was replaced three months ago and car performs normally. Any ideas?

 

could also be the auxillary battery under the hood as stated above in a previos post, also could be the alternator or the regulator in the alternator

 

Put a digital voltmeter across the battery terminals and see what you get, probably 13volts. Without starting the engine put on the headlights and you should see a slight drop in terminal voltage to say 12.6 volts (depends upon how many lights you switch on). If the battery voltage drops alot (say to 11.5 volts) the battery is not in a good state of charge or is puffed out. Now turn the lights off and start the car, if the alternator is charging the battery terminal voltage should rise above the originally measured unloaded voltage of 13volts, to perhaps 13.6volts. If the battery voltage rises when you start the engine the alternator is charging, simple as that. Hope this helps as it is a cheap and easy way to test your charging system.

 

On one of my Es, I had an alterator that checked out fine but was intermittently charging correctly then switched to sucking the power out of the battery. A new alternator solved the problem. +1 to chassis221 comments.

 

Thank you for the information. I had the Aux battery checked and it was bad, so replaced it and seems to work fine now. By the way the local "Mercedes Authorized " repair center, not a dealer, Did NOT know there was an Aux battery!

 

sometimes its really better to go to a dealer...but trust me...there are some bad dealerships out there. Also good and bad " Authorized Mercedes Dealers" too