Notes on the 12 V battery
WARNING Risk of explosion due to electrostatic charge
Electrostatic charge can ignite the highly explosive gas mixture in the battery.
To discharge any electrostatic charge that may have built up, touch the metal vehicle body before handling the battery.
The highly flammable gas mixture is created while the battery is charging and during starting assistance.
WARNING Danger of chemical burns from the battery acid
Battery acid is caustic.
Avoid contact with the skin, eyes or clothing.
Do not lean over the battery.
Do not inhale battery gases.
Keep children away from the battery.
Immediately rinse battery acid off thoroughly with plenty of clean water and seek medical attention immediately.
ENVIRONMENTAL NOTE Environmental damage due to improper disposal of batteries
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.
If you do not intend to use the vehicle over an extended period of time:
activate standby mode, or
connect the battery to a battery charger approved by Mercedes-Benz, or
consult a qualified specialist workshop to disconnect the battery