Work carried out incorrectly on the battery can, for example, lead to a short circuit. This can restrict functions relevant for safety systems and impair the operating safety of your vehicle.
when braking
in the event of abrupt steering manoeuvres and/or when the vehicle's speed is not adapted to the road conditions
For safety reasons, Mercedes-Benz recommends that you only use batteries which have been tested and approved for your vehicle by Mercedes-Benz.
Electrostatic charge can ignite the highly explosive gas mixture in the battery.
The highly flammable gas mixture is created while the battery is charging and during starting assistance.
Battery acid is caustic.
Batteries contain pollutants. It is illegal to dispose of them with the household rubbish.
Dispose of batteries in an environmentally responsible manner. Take discharged batteries to a qualified specialist workshop or to a collection point for used batteries. If you have to disconnect the 12 V battery, contact a qualified specialist workshop.
Comply with safety notes and take protective measures when handling batteries.
Risk of explosion. 
Fire, naked flames and smoking are prohibited when handling the battery. Avoid creating sparks. 
Electrolyte or battery acid is corrosive. Avoid contact with the skin, eyes or clothing. Wear suitable protective clothing, in particular gloves, an apron and a face mask. Immediately rinse electrolyte or acid splashes off with clean water. Consult a doctor if necessary. 
Wear safety glasses. 
Keep children away. 
Observe this Owner's Manual.
Activate standby mode.
Alternatively: connect the battery to a battery charger approved by Mercedes-Benz or consult a qualified specialist workshop to disconnect the battery.