Was reading your thread about Mercedes Auxiliary relay issues a customer was having. I'm having similar issues and
![w211 e320 cdi 2004 battery visit workshop brake light on | Electronics and Audio | MBClub UK - Bringing together Mercedes Enthusiasts w211 e320 cdi 2004 battery visit workshop brake light on | Electronics and Audio | MBClub UK - Bringing together Mercedes Enthusiasts](https://forums.mbclub.co.uk/data/attachments/47/47604-c7ac36ec2e3bf24bb08bde44b1c4996b.jpg)
w211 e320 cdi 2004 battery visit workshop brake light on | Electronics and Audio | MBClub UK - Bringing together Mercedes Enthusiasts
![E55.........just a flat battery? | Electronics and Audio | MBClub UK - Bringing together Mercedes Enthusiasts E55.........just a flat battery? | Electronics and Audio | MBClub UK - Bringing together Mercedes Enthusiasts](https://forums.mbclub.co.uk/data/attachments/55/55857-342dbd7c74842e578ed4c68cd49179f6.jpg)
E55.........just a flat battery? | Electronics and Audio | MBClub UK - Bringing together Mercedes Enthusiasts
![Mercedes W211. Battery was discharged after a month of downtime in the cold / Dead battery W211 - YouTube Mercedes W211. Battery was discharged after a month of downtime in the cold / Dead battery W211 - YouTube](https://i.ytimg.com/vi/BBzK35KDh8Q/mqdefault.jpg)
Mercedes W211. Battery was discharged after a month of downtime in the cold / Dead battery W211 - YouTube
![Mercedes-Benz W211 Auxiliary Battery Replacement (2003-2009) E320, E500, E55 | Pelican Parts DIY Maintenance Article Mercedes-Benz W211 Auxiliary Battery Replacement (2003-2009) E320, E500, E55 | Pelican Parts DIY Maintenance Article](https://cdn4.pelicanparts.com/techarticles/Mercedes-W211/71-BASICS-Auxiliary_Battery_Replacement/images_large/pic01.jpg)
Mercedes-Benz W211 Auxiliary Battery Replacement (2003-2009) E320, E500, E55 | Pelican Parts DIY Maintenance Article
![How to test an additional battery SBC Systems for Mercedes W211, W219 / Battery charge test W211 - YouTube How to test an additional battery SBC Systems for Mercedes W211, W219 / Battery charge test W211 - YouTube](https://i.ytimg.com/vi/NKuolRBQNlw/sddefault.jpg)
How to test an additional battery SBC Systems for Mercedes W211, W219 / Battery charge test W211 - YouTube
![Causes of errors Service brake! Visit workshop! & Reduced braking power! Start engine! on W211, W219 - YouTube Causes of errors Service brake! Visit workshop! & Reduced braking power! Start engine! on W211, W219 - YouTube](https://i.ytimg.com/vi/gvRTw4Ar0dM/mqdefault.jpg)