PHML

Hey guys, anyone experienced thus or something similar?

I was driving to dinner last night...noticed msg on my display about low key battery. After dinner, drove straight home...same msg on display. Parked her in the garage.

An hour later, I noticed the Smart Keys were acting up. One key was completely dead. The other Smart Key was only able to Lock-Unlock-Pop Trunk by pressing buttons on the remote...it was not able lock or unlock by touching the driver door handle.

I drove to a convenience store at midnight and bought new CR2025 batteries for both remotes...installed and now, same thing. At 1 am, I call up MB Roadside Assistance, they says it's a dead car battery. I confirm this, my interior lights are dead now. I have a battery charger, so I decided to charge it up myself and hope for the best.

The car has been charging for 5+ hours at 2 amp mode...the battery is at 50%. I tried the Smart Keys again....same thing...with new batteries in the Smart Keys...one does not communicate at all with the car....the other was able to Lock-Unlock-Pop Trunk by pressing buttons on the remote...it was not able lock or unlock by touching the driver door handle.

Also car wont start....Keyless Go is not working. Pressing the start button usually brings up the display options, but this also does not appear on the front console.

Any ideas?

ghstudio

May not help, but I would remove the "push to start" plastic button on the ignition switch and try to start the car using the normal mercedes key. I also seem to remember a post a while back that talked about a separate backup battery for keyless go...and that battery might be dead. Not sure how that battery gets recharged..perhaps not from your main battery, so maybe it has to be replaced by the dealer....but that's just a guess.

ImInPA

If the battery was very dead, it will need to be at or above 80-85% before things will return to normal. If it was totally dead , the keys may need to be reset at the dealership.

PHML

Thanks...I'll ask about that.

Wow...didn't know that...read the operations manual...too bad it didn't say anything about being 80+% before normal operations are returned. I suspect a visit to the dealer (tow) is imminent. Why one Smart Key partially works, and the other does NOT work...is beyond me at this point.

hyperion667

that's a lame ordeal to endure......sorry to read it....
funny because my change key battery warning or whatever
came on yesterday......
the batteries are those 1.5V round chip batteries I think......

PHML

Yes...remote battery is CR2025...one each per remote.

axhoaxho

With modern 'electronic-heavy' cars, once a car battery is 'weak' I would just replace it with a new battery, for the peace of mind.

Last time I had a 'marginally weak' battery on my C350; it caused all the electonic hiccups, long engine cranking to start, and eventually the car wouldn't start one morning in the garage and caused me missing a very important business appointment (not good.)

My dealer recharged and reconditioned the battery, tested it three times, and returned the car to me saying it was fine.

A month later, the battery went back to 'marginally weak' again, caused all the electronic hiccups again, and eventually the engine failed to start and caused me late to another business appointment (not good, again.)

I brought the car back to the dealer, they put a new battery in, and all was fine since (they should have done it the first time.)

I am biting my tougue to say this... but now whenever I purchase a new Mercedes, in every two years when I do the Service B, I just ask my dealer to install a new car battery at my cost. And now with my new E350 that has Keyless Go, I would also replace the car key batteries every year during Service A, as a precaution as well. I know, I know... but it is from my hard lesson learned.

Just want to share my experience.

With best regards,

ImInPA

Believe it or not, the battery charge range is very very narrow. I think a battery is considered dead if it drops much below 11 volts. I just replaced the battery on my bike and have been doing some research. Go the the TruGel or Battery Tender battery site and they have lots of explanation. A car and bike is not like an iPod where you can do a "quick" charge to reboot it. Cars need strong, well charged batteries.

PHML

I wonder why my battery is already dead? Its a 2010 vehicle. Most batteries I know last 3 -4 yrs. With all the extra electronics, do you think its draining the battery quicker? Or maybe my alternator is dead?

petee1997

Most probably a defective battery and should be replaced on warranty.

ImInPA

I would think warranty would cover this. It is certainly not normal wear and tear. But, I think you should just replace the battery regardless of it being covered by warranty.

PHML

UPDATE: I got a MB Roadside Asst to give me a jump this morning. My car battery was STILL not charged up enough to start the vehicle (2 amp slow charge for 36 hours = still weak battery).

After a couple attempts to start the car with Keyless GO....no luck. No sound at all.

The tech ask me to remove the Keyless Go button and stick the Smartkey in the ignition...I did that and it started up without hesitation....wow!!

WTF?!?!? Keyless GO is a NO GO!!

Also, my remotes still have issues....before and after replacing both remotes with new CR2025 batteries.....1 still does not work, and the other partially works. I drove straight to my the MB dealership after the car started. I checked it at Servicing and told them everything that happened since Sunday night.....dead battery, charging at 2 amp since Sunday evening, both remotes not working properly even after battery swap, unable to start w/ Keyless GO, etc...

The MB service rep says he just did a quick look...he claims everything seemed fine. I asked for a new battery, and I dont want to be stuck somewhere. He claims the battery seems fine, but they will check it out.

Right now...im waiting for their call when its ready for pickup. I sure hope they find out WTF is wrong with my car....ARGHHH!!!!

ghstudio

Gosh!!! where did I see that suggestion

PHML

More updates...MB dealership charged my battery all day...tested it and it failed their test....now getting a new car battery. Let's hope my remotes and Keyless GO also works properly.

hyperion667

sounds very annoying/frustrating.....
you just got your car no?
an experience like this could really ruin the love for the car....
but I hope that doesn't happen.....

good luck, hopefully this battery business will be the end of your troubles you know?

PHML

Thanks bro...love the car, but my experience with the battery is water under the bridge...time to enjoy the car.

DanielDuc

Sorry for bringing up old thread,

but did replacing the battery of the car fixed the keyless go key problem?
I'm experience same problem.

I'm sure hes not on here anymore but was wondering any other members experience this problem

hyperion667

car sounds nice! throw some pix up!

mrchrisbarbour

Yes, same issue here on a 2011 e550 coupe, charged for 24 hours on AGM setting, car and everything else works perfectly EXCEPT KEYLESS GO. I have an appoinyment on Wed at the dealership. What a pain for something so small.

El Cid

The battery in my 2010 died at 48.5 months (2 weeks after warranty expired) and had to replace it. Got it from the Roadside Assistance person and then found out the $300+ MB battery is only warranted for two years. MBUSA confirmed the very short warranty on a very expensive battery.

OAG

E350 MY 2010. Had battery problems last 2 months. Had to get RA jumps twice. After second one took car in. Dealer replaced the cooling fan (one in front of radiator) said it was drawing too much power. They also replaced a wiring harness that was unrelated to the battery problem. Also replaced the Battery with a new one. All work took about 4 hours an was all covered by warranty (no cost to me - this was in the 46th month of the initial 48 month warranty). Car now covered by MB ELW for another 36 months beginning 3/1/2014.

Arrie

There is something here to understand. As long as the simple part of the car, like the battery, is not covered under warranty DO NOT GET IT FROM THE DEALER! They charge 3-4 times for the part that they do not make and is nothng special. You can get a battery from an AutoZone or NAPA or anybody with more than twice the warranty with less than half the cost.

A car battery is made to give 12 volts and enough cranking Amps to start the car. You think the U.S. made big V8 engines take less amps to start so the batteries made and sold here are not good for a German car?!?

After warranty get the battery (or brake components) from third party suppliers. They are as good and in most cases better parts than the OEM parts for much less cost.

Any high quality or luxury car dealer pricing is based on the fact that most of the people buying their cars don't know what a spark plug is. And they don't need to either...

douwe22

had a problem with my c63 key fob , was able to unlock car and trunk but not able to lock the car, replaced the key fob battery with new one and still had the same problem then I decided too hold in the key fob unlock button for like 30 sec while sitting in car, now everything works, go figure! maybe this will work for some of you! goodluck..

jhodies

I know this is an old thread, but does anybody know if there is a battery voltage reading in the dashboard computer? If so how do we get to it? I read somewhere on another thread that a dealer salesman showed him how to do it. Basically I need to check the battery voltage just to confirm that I need to buy new ones.

screw991le

Had the same issue. Replaced it with a AGM battery, just to be even more cautious.