novae500

Its very easy and less than 10min to do. Just make sure you get a motorcycle bs14 battery that you do not need to fill the acid into the battery. Just get the one thats already to go. Power Magna is the one i got from advance auto for $93 online (coupon codes you can use and pickup in store)

keksixsigma

welp here we go again. I replaced the aux batter with magna power, 30 secs and light came back on after starting. Put a charge on battery just in case, started it up in morning same thing. Getting towed to MB dealer now.
Anyone want to buy a stage 3, 550 whp, 10K miles on motor, complete rebuild by Ted MPower Houston, TTM 82mm, 550 cc inj, TTM fuel rail, Kleemans, 180 asp, Eurochaged ECU, TCU, tank resvivior pump, new starter, rear bat, HRE wheels for what I owe on the car get all the rest for free, I'm done with this car

jcjmw

Frustrating, I know. But, the dealer should be able to diagnose the problem, replace the part and you are back on the road.

moosejaw

Guys with the AUX battery I recall you have to precharge it before you install it.
I also recall not precharging before installing and noticed the light still came on.
Maybe this is why you still have the light

keksixsigma

I did charge it. Hope you are right and just needs to reset. I'll keep you informed of the outcome. Thanks guys.

gaspam

haha i am pretty much in same boat with my car... ready to sell it!

mine problem ended up being the alternator and is fixed now and want to sell it and just not deal with it anymore....

boschk

Buy a multi-meter. Otherwise you can't test what you need. The batteries should be putting out 12v without the motor running. Then, when you start the car, the batteries should be putting out at least 14v, telling you the alternator is charging.

My aux battery is putting out around 6.7v without the motor running, so it's toast.

The typical AGM battery comes charged from the factory, but 2 seconds with a multimeter and you know before you waste your time. A decent meter is $20-50 from most auto stores. It's a great investment for any electrical troubleshooting.

I have this one:

boschk

Alternators don't last forever and they are not hard to test for failure nor hard to install. You can get a bosch unit off fleabay for around 300 bucks and install in less than an hour with basic tools.

I'll buy that bucket of bolts! 15k considering all the trouble it is.

novae500

i was ready to sell my car too...but still have the urge to go out and drive it and see what it does to other cars....yes very frustrating when things go wrong, but smiles when its running without issues....

Which code are you guys still getting? Low convenience?? or Red Battery code...

boschk

https://mbworld.org/forums/mercedes-...-tutorial.html

gaspam

yeah alternators are super easy to change out, but not when you are 200 miles out of the city on your way to atlanta and you need one right then

i didnt want to sit on the side of the road for 3 days while i waited for an ebay one to be delivered to me

i am thinking in the low to mid 20k range price-wise on a sale since everything on this car is fricken new now including the airmatic lol

boschk

You don't keep a spare handy?

Yeah, you get too far out of town and you'll hear, "I never worked on one of doze befur." Run!

gaspam

lol no i figured most shops would have them in stock, but i was wrong

at least by using the dealer i got a complimentary tow and ride back home lol

still would of rather had it just not start up in my garage so i could of ordered one and saved $700 by installing it myself... oh well 996 porshce TT is looking a lot more attractive these days

selen1um

Guys I have same problem. Red light battery icon visit workshop, also headlt. cornering message, my engine light is on when car is started. I replaced the AUX battery from the dealer for $180 and light is still on. Here is youtube video of exactly what happens when I turn the car on.

https://www.youtube.com/watch?v=NbBD...er_detailpage2

Please help. Thanks!

meridien

car has been stoped for one year do to trunk not opening cant boost battery found a way to open truck. nowtry boosting battery no start message in cluster workshop with picture of battery .does anyone know how tooclear mess ,now try to charge battery thanks

selen1um

Bad battery or your alternator not charging it. Bad voltage regulator? Check those 3 battery, voltage regulator and alternator at the end. I had same problem, i ended up having bad alternator. Don't get one from dealer!

I Like Soup

I got a Bosch alternator from Amazon for around $260.

You really shouldn't be paying more than around $75-80 for the accessory battery or around $110ish for the main battery.

Good luck. I absolutely hate this error on our cars. Makes me think twice about another Benz purchase.

E55Dimon

Anyone selling an alternator? Lol

sufyaanahmed

Had the same issue red battery light on my dash while driving the cars electronics first cut off then would not accelerate at all and it would start accelerating again then the worst part the brakes stopped working I was in traffic when all this happen very dangerous my battery was drained and my alternator had this weird burning smell I changed the battery first too see if that solved the issue it did not replaced the alternator and car drives 10 times better. Very scary situation when the electronic brakes failed.