Hi. My car is a 2003 E320 with 60,000 miles. The visit workshop message comes up with a red battery icon.
Lately, when I have the lights on, the lights go off and come back on right away and the clock turns around and stops where it was originally. I had it checked at a local gas station and they said it was the auxillary battery that needs replacing. Also the main battery needs charging. I didn't get the service that time because I did not have time. The Mercedes dealer told me over the phone that it was probably the battery, which would cost around 600 to replace. The local gas station said 315 for the auxillary battery and they are the only ones who looked at the car so far. The car runs fine.. I know it needs attention soon so what are some opinions or experiences that will help me.
The car has been great so far,
thanks

 

Yep,

Looks like the battery. Normal life 4 years.

Your car has two batteries so as to assist in preventing you being stranded with battery trouble.

Your vehicle is actually telling you that the battery (or alternator) needs attention.

When changing the battery cost isn't everything. Differing battery technologies exist and this is usually reflected in the warranty offered usually 3 OR 4 years. 4 years costs more because of the technology.

When changing the battery ensure that the alternator is working correctly otherwise you can wreck the new battery.

Since MB's are so sensitive to battery issues I would fit a battery of the same make/type as OE MB (Bosch, Varta, etc) but not necessarily from an MB dealer who will charge a premium.

600 USD? Sounds a little over the top!!...so does 300 USD for that matter.

Stuart

 

Agree with the cost. Cant speak for the secondary backup battery and have no clue as to it's location or complexity of replacement.
The "under the seat" battery is easy to access and can be bought rather cheaply. I had to replace mine a month ago. Went to Interstate, and asked for a "blem".
They are either disfigured or casing damaged. Not generally a functional issue and never a leakage issue that I have seen, and if they are defective they come with a warrantee. In the 25 years of buying them, I have only had one that has been defective, and I run 3 cars at a time, with all of my cars being older.
Since the battery is under the back seat, there is not a cosmetic component to this. I also opted for a few more cranking amps for this northern Chicago climate, where this week it will be Zero Degrees or below, every morning this week. If it slightly shortens starter life. So Be It! Rather that than stranded in the cold. It cranks over quickly in even the worst temperatures.

Cost for an installed blem was under $40.oo. Installation is free. I can buy a lot of blems for $300 to $600 bucks.

Don't get hosed by a dealer or shop, friend.

Aardvark.

 

I got the heads up on replacement batteries from a MB workshop manager. He said that a lot of people are going back to lead-acid, not just for cost, but also for serviceability. My 03 E500 has very low miles 30k, and it was lack of use that caused the problem.

The small battery is under the Hepper air filter on the passenger side. Very easy to get at.

I changed the big one for a pattern part. $75 and it was exactly the right shape with pipe point ready to drain. 2 year warranty .

But the red warning came back.

The small one was as dry as a bone. Looked like the plates were bulging out of the layers. I'm getting interstate to look for one for me, if no luck I'll use a motorcycle battery! The max amps could be important however. One of the jobs this little'un has to do is take over the brake duties if the rear one gets smashed in a rear-ender for instance. I can see that this might take a good few burst of high current. I would have thought that a 4 cylinder 1000cc bike would take some cranking, and I know they will stand many tries to start from quite a small battery. Mine is 5.5" by 3.5" and fairly tall say about 6". This is bigger than a lot of big bike batteries.

My car looks like new, and I don't want to be too cheap about it, but $600 !!! where are they coming from? Sheesh...you could get an aircraft battery for that.

 

I'm trying to find out if this is pretty well what was the original.


http://www.yuasa.com.au/asp/index.as...=135&type=1208


I've had them side by side, and they look the same, but who knows. $85 instead of $208 or $150 from a small dedicated MB service center.

CAUTION There are two types listed for one year. One is like the above and a smaller one that's white.

 

there are software flashes to update your battery control module.....also there is an auxillary battery relay that do commonly go bad that couples both of the batteries together. that can cause the same battery light your getting. if you go to benz they can run a test to see if there are codes for this relay. its under the passenger side windshield under the hood under the water catcher/cowl.. you can actually see it when you replace the small auxillary battery. has 3 wires going to it i think maybe 2.

 

Any idea what this is?

On mine, the wire going to the axillary battery has an electrical socket tapped into it, with a little module plugged in. It's black and about an inch and a half long. The 2 connecting pins are very small and non reversible.

 

thats called a fusible link. but this part is under the cowl...black plastic cover under the wiper its about 4 or 5 inches long and mounted on the firewall area but up under the cowl...youll have to put your face close to the battery to actually see it.. maybe im wrong and maybe your car doesnt have one.. ill try to get you a pic.

 

Thanks for your help.

Okay, I can just see the relay under the plastic where it curves down. That curve provides a water shield of sorts. The fusible link takes power to an unknown place. I have a feeling that it was installed after the car was made, as there is some PVC tape at the interception. I bought the car at 25k so am not sure if any other kit was retrofitted...can't see anything. Mind you, it would make sense for an alarm to be powered by the standby battery. Less lightly to be found by a thief with a trailer - someone that would disconnect the main battery and haul the car away.

As for the replacement battery. Well, I'm really a bid disapointed. The Yuasa battery - that seemed to exceed the FIAMM original spec - doesn't weigh as much. About 7 lbs instead of 9. You get what you pay for I guess. However, I'd sooner have a new battery, and one that will crank a big motorcycle, rather than a tired old one of a supposedly higher spec.

It's in, and all warnings have vanished. The computer will retain the details I'm told.

I phoned FIAMM (the makers of the MB labeled original ) in the US and the lady said that they don't to ANY automotive batteries here. All come from Europe. It seems that they specialize in Axillary / Standby batteries, yet leave out one vital group. Odd that, I would have thought that could have been an ongoing market.

 

If you get this lite, is there any way to know which of the two batteries is the problem or is it hit and miss?