A.M.

the batteries are 2012.

Critter

It sounds like you are state side, and are not using the car. Take both batteries out of the car and take them to autozone or similar place and they will charge and load test for you, free, only 2 years old seems kind of early unless the battery has been drained flat for a long time. If both are 2012 then obviously the load test will prove them good and you can go from there.

E2233

I have 2009 E550 purchased new in 2008 with about 70,000 miles. The last time I took the vehicle in for service the dealer June 2014. The dealer recommended replacing the battery. I have had any problems starting or with any of the equipment in the vehicle.

I took the vehicle in to a local shop for some repair a few days ago and they recommended replacing of the battery. The first shop wanted $350 to the second shop wanted $450.

One shop said the battery did not past their test.

Any recommendations?

Critter

@E2233, your present battery has given you piece of mind for 6 years and 70000miles now, 2 different places have recommended you change the battery. You can ignore their recommendations and run the battery to failure at which time you will be inconvenienced whether it is waiting for a boost or replacing a dead alternator trying to keep the giant resistor up in charge.
Look at Interstate AGM batteries, replace and forget for another 6 years.
If you plan on selling the car then disregard.
Some people are lucky to get more years out of their batteries but batteries will usually fail on the hottest days and obviously the coldest days and always at the wrong time
250-300 max, shop around

E2233

Thank you for your fast reply.

There are plenty of accessories that are draining battery in these later model vehicles.

I called another dealer that I buy parts from sometimes. I got a quote of $271.00. They dealer called me back and match the price with an installation charge of $90.00. I agreed my car was in the shop for some warranty work and I am using a loaner. I am always concern when changing the battery with the radio code and other electrical equipment that uses the battery. If there are any problems the dealer will be able to fix it before releasing the vehicle.

cetialpha5

Depends how dead the battery was. Mercedes uses a pretty big battery, I think stock is 85 amp hours. So if it was really dead, 2 amps would take 45 hours. Probably longer because you have line losses so you don't get the full 2 amps. Could also be slightly dead.

As for the Aux battery, not sure how it's wired, but you could also just take it out and charge it separately. I've also read that the aux battery only gets charged for a short period after you turn the car on and then it gets shut off until you restart so you're just better off taking it out and putting it on the charger.

Also E2233, if the first shop quoted $350, was that installed? Because $271+90 is now $361. Anyway, I would have just gotten the battery at Advance Auto, it's an AGM battery at $189 with a $50 discount code that can be found online brings it down to $139 installed. They don't call them stealerships for nothing.

E2233

Just returned from dealer total cost installed with taxes $394.00. The first shop may have included the installation that was June last year. Both dealers had additional recommendations based on time and mileage.

I am always concern about losing the radio code when the battery is changed.

I will keep your recommendations in mind for my wife's 2000 E320. I replaced the battery about 8 years ago and in the future with my E550.

My daughter's Chevrolet SUV battery had to replaced a couple of months ago the dealer wanted about $350.00. I called a dealer where my family has bought 4 Chevrolet from them. They parts department wanted $350.00. I called the guy we purchased the vehicles from he called service. The battery $140.00 installation $40.00. The service rep was a little bent out of shape.

ibeforreal

I have an S Class and the most I have ever paid for a battery is $150 and it weighs about 40 pounds.

StarvingArtist

You can connect your car to another battery with jumper cables while you switch to avoid power interruption.

wjcandee

HECK YES!

Take it to Advance Auto Parts and have them test it with their Midtronics tester. Tell them that you know the battery is old, but it seems to work fine, so you just thought you should check it out. That tester is the only one that will reliably tell you what's up with an AGM battery, and it's the one the dealer uses. Advance is generally very, very honest about this stuff, and you can see the reading yourself.

If you have some more life in the battery, keep using it. When it goes, it will likely REALLY go, like all sorts of weird electrical gremlins and flashing lights and stuff, unless it dies in its sleep overnight in the garage. More likely the former than the latter. Or you will get a red battery message in the cluster.

Then you have some choices. Advance has a very nice Autocraft Platinum AGM battery, and most will put it in free for you. About $188, but if you order online for pick up (or installation) in store, there is always a coupon on the web site good for 15% off at least, plus usally some money on a gift card (like $20). That makes that battery a very good deal.

If you're up to installing it yourself (easy and plenty of youtube videos on how), you can order from Rural King, probably the least-expensive AGM battery out there in our size, and it's really like a repackaged Exide Edge, a very good battery. This private label Exide L5/H8/Group 49 AGM battery is back in stock and available every day for $139. Through August 2015, comes with a $20 rebate from its manufacturer, Exide. And a 36-month free-replacement warranty PLUS a 7-year prorated warranty. Probably the best consistent buy out there. http://www.ruralking.com/automotive/...k-agml5-49.htm

E2233

Thank you for the information. I had the battery replaced during servicing at the second dealer. I had the same opinion as you did. I checked some other posts on the board that indicated the battery may have reached it ends.

I remember on my E320 2000. The battery failed without any notice. I did learn the best places to purchase a battery. I did over pay for the battery and the installation at the dealer. I was worried about losing the radio codes or other problems. I did end having a problem with the key less entry after the installation of the battery. The trunk does not open now without opening one of the doors. The dealer told me that my car did not have that feature. I purchased the car new with factory delivery in Germany. The feature all worked until the battery was changed. I will have to take it back to the dealer for a second time to fix the trunk lock now when I have time.