Besides the obvious things like car won't start, what are the telltale signs when the battery is getting tired? I have a new to me 2008 CLK350, 4 years old with 40k on the clock.

It is starting to do some strange electrical things. I can't see the little eye in the battery but I honestly don't know what to look for. Is the MB battery service woth it or is autozone the way to go?

Thanks for the input.

 

if you have juice left in your battery, go get yourself a trickle charger from amazon. and let it set for 4 to 5 hours. you're golden.

*assuming that the merc battery is the same as any other battery out there.

 

It an Clk not an SLS? who care if the battery does not said Mercedes on it. It under the cover anyway that no one can't see. I went with Walmart and $70 !!!!

 

I agree with Klinh, as long as the battery fits, the hold down clamps engage it and the CCA are equal, it's good to go. I would have changed my battery out to an Optima red top if the choice was available here when mine died.

 

I forget what my symptoms were, but I called MB Roadside assistance, which is free for ALL MB owners, regardless of age. My battery voltage was a little low, and the tech happened to have a nearly new battery with him that had just been warranty-replaced out of a new E Class. He sold it to me for $40!

 

For around a month before my battery died (couple of weeks ago), the voltage according to the MB diagnostic system was around 10.x V when it should be a bit higher than 12. Second indication for me was the dimming/flickering of interior and instrument cluster lighting when starting the car.

 

You can tell by the Voltage... use you're cluster to see the battery on start.
if the voltage is below 11.5V or 11V then your battery is going..going...gone....

 

Not any more! MB Roadside Assist on pre-2011 models is now only available to the original purchaser. Subsequent owners get roadside assist until the factory warranty expires, and then it is terminated, unless the vehicle has been serviced by an authorized dealer within the prior 12 months. However, some roadside service centers (usually dealers) will still
dispatch for a dead battery, but that's up to the individual dealer.

As for the answer to the OP's question, the symptoms of a dying battery are very subtle, if detectable at all. Modern technology is such that most batteries simply "die". The one in my C240 did that last year. I had driven to work and it started just fine that morning. I went to go out for lunch and there was enough juice to operate the door lock and that was it. The ignition lock wouldn't even accept the key.

 

I have had really good luck with MB batteries. I have had my 2000 E320 since new and have replaced the battery one time with the help of Roadside Assistance. It cost the same as putting it in myself so I just let them bring it to me and they installed it for me.

 

I am going to take it Autozone tomorrow and let them put their load tester on it. The little green magic eye in the middle of the original battery is not green any more so I am pretty sure that the thing will need replaced. My only wonder now is what happens to all of the electronics once they disconnect the battery. MB keeps everything powered up through some aux connection when they swap out the battery. Anyone done this on their own like this? Anything I should worry about?

Tnx again..

 

Do NOT use one of those plug-in power retention devices! Just disconnect the battery (negative lead first) and replace it. There are only two things that will be affected - ESP and the auto feature on your power windows and sunroof. To reset ESP, start the engine and then turn the steering wheel fully lock to lock (this resets the steering angle sensor). To reset the windows and sunroof, open them fully then close them by holding the switch in place for an extra 10 seconds after the glass is fully closed.

 

This would be good info for a stickie.

 

Just dropped it of with MB. Fortunately, it wouldn't start for them either. I was concerned because it has been doing this very intermittently. In fact it took five guys to push the car in to the service bay. At least I am fairly certain they will be able to fix this while it is still under the original factory warranty. It expires midnight tomorrow night.

I hope it is a quick fix. I hope this pre-owned decision wasn't a bad one. I've only had the car three weeks.

 

Back from the dealer and repaired. Needed a new starter motor.. All covered under warranty. Hopefully I won't need to see the service department again until scheduled maint.

 

Rodney himself should be stickied

 

Are you staying I should just "stick it"???