Dead Battery/Drain




This winter it would not start after 5 days parked at the airport. Mind you it was cold maybe -15C but my other cars never have a problem starting
Then twice since then it would not start. Today it was completely dead. I had to use the mechanical key to open it. And I drove in 2 hours 3 days ago.
I have read the threads regarding blower motor staying on, one thread claiming a bad battery cable, another with some bad module under the steering wheel.
Any other people with this problem?
Get it diagnosed at your dealership, hope you are still under factory or extended warranty! There's definitely a draw coming from somewhere.
Good luck.
Fast forward a few weeks. This past weekend it was deja vu. Only this time the car hadn't been driven for one week. This time it wouldn't respond to jumper cables or a trickle charger. So, another call to roadside assistance. All they did was jump it with a portable battery but the POS did start.
They also told me that contrary to urban myths on this website, Mercedes roadside assistance WILL NOT replace a battery on an R500. They said to schedule an appointment at a dealer. The dealer said 2 hours to replace a frickin battery! That's ridiculous. Any design that requires a skilled technician to spend 2 hours replacing a battery is a poor design.
So, the dealer will not be replacing the battery. Sears sells an AGM equivalent for $145 (US). Mercedes will however be getting the car back to find the source of the current draw. No car battery less than a year old should lose all of its charge in seven days in 80 deg F weather.




I am appaled generally at the poor troubleshooting skills and tools that the dealer has. They should be able to hookup a current draw sensor to main distribution and let me drive it for a week. Had they not found the problem I would have built on myself!
as for time required to change the battery, well it is under the drivers seat. 2 hours is a bit much, maybe 90 minutes is better. An hour for the junior mechanic that does this once a week... this is not rocket science!
Dealer removes the seat because it's a tight and uncomfortable removing it how the manual directs to do this and the battery is huge and needs to go in and out at an angle. Space is very limited. If I had more time I probably would remove the seat too.
I thought about Interstate, it is still pretty expensive, I think ~$300 + tax and I could only buy it at some mechanic shop in Canada which wants they commission too.
What battery brand and type would be the best replacement for the stock OEM?
Trending Topics
http://www.sears.com/diehard-advance...1&blockType=G1
Not sure this helps Canadians though. Do you have Sears in Canada?
The Best of Mercedes & AMG




Dealer removes the seat because it's a tight and uncomfortable removing it how the manual directs to do this and the battery is huge and needs to go in and out at an angle. Space is very limited. If I had more time I probably would remove the seat too.



