Bought our 2001 C320 from the dealer a few years back. We do not drive it during the winter. It sits in the garage (unheated) every year. Battery remains connected because we need to move the car out occasionally to bring in firewood. Every year the car would start fine in the summer, no problems. And we don't drive it much, maybe 3000km a year (1800 miles). Never a problem, until yesterday.

I went out to start the car and nothing. No dash lights, and I could not get the electronic key to turn at all. Assuming the battery is dead, I pull up the truck and hook the batteries up (as per manuel instructions). Good connections. I can then turn the ignition and get dash lights and chimes to sound off, but it still will not turn over.

I called the dealer who is 2.5 hrs away and they will not diagnose or offer suggestions over the phone. They only recommend I have the car towed in. Uh-huh, yeah right. Let's see, I wonder what a 6 hr round trip tow truck would cost?

So, I'm looking to draw upon the Internet Collective to assist.

Thanks in advance.

Jim

P.S. I've read https://mercedesforum.com/forum/mercedes-c-class-10/c320-battery-replacement-problems-17839/ and https://mercedesforum.com/forum/mercedes-c-class-10/c320-battery-drainage-25696/ but would like to determine if there is some electronic gadget that is preventing start before I try to determine why the battery drained.

 

I suggest you hook up a charger for a lot of hours until it shows some charge.
If there is no charger available then hook up to a donor car and run the donor car a little above idle with NOTHING turned on in either car for at least 15 minutes. This should provide a small charge to the dead battery. I have done this in the past with MB diesel cars and picked up the tip from a tow truck driver after killing three donor cars one winter night. After 15 minutes try again to start your dead car. Unless something is wrong with the starter the extra boost from the partial chatge should do the trick.
Like you I rarely drive my sport coupe and it sits outside 24/7 all winter totally buried. A 12 hr battery charge ensures the battery stays charged.

 

Thanks. So what would you consider a lot of hours? I actually am dealing with 2 dead batteries, one on the C320 the other in the Chev Avalanche. The AV is the daily driver (rural living, rough roads). I had the AV batt on a 24hr trickle 12V charge. Worked in the past but it didn't do a thing this time. Might be the charger (borrowed). I might just go buy one myself since every year there's always one batt on one of engines that goes kaput.

Jim

 

When the battery is totally discharged, and from the way you use the car (very little) I suspect it is so, it often will not accept a charge. Take it for a 24 hr charge and see what happens. The one for the Chevy might not have had a large enough charge for the MB. See if it accepts a charge before you spend in a charger.

Once the problem is solved, you'll get your answers. Then, solve it as it fits you and consider getting a trickle charger to boost the MB battery at the end of next Winter, but remove it from the car while no being used or run it for at least 10 minutes per week.

 

Thanks. The batt in the AV was taken from the '01 Silverado I also have, HD batt to run a 8.1L v8. Bigger than the normal AV batt. I thought for sure it would jump the MB. I see a batt charger in my future.

 

As I mentioned I have a battery charger. It has a low trickle (2A), a medium (15A) and a 100A quick start. Useful for all occasions. Having said that, if the battery has been dead before or is getting elderly it may not accept a charge as JoeVal mentioned.

 

I took a look at the batt earlier this evening. Its an MB battery, definitely not aftermarket. That's no confirmation that its original though even though the car has less than 45000 miles on it. I was actually surprised at the size.

What's the best way to test if a batt will still take a charge?