2001 Mercedes SLK-Class Owner's Manual - Page 214

Therefore, we strongly recommend that you have the battery charge checked frequently, and corrected if necessary, especially if you use the vehicle less than approximately 200 miles (300 km) per month, mostly for short distance trips, or if it is not used for long periods of time. Only charge a battery with a battery charger after the battery has been disconnected from the vehicle's electrical circuit. Always disconnect the battery negative lead first and connect last. When removing and connecting the battery, always make sure that all electrical consumers are off and the key is in steering lock position 0. The battery must always be securely installed when the vehicle is in operation. During removal and installation always protect the disconnected battery positive (+) terminal with the cover attached to the battery. While the engine is running the battery terminal clamps must not be loosened or detached, otherwise the generator and other electronic components will be damaged. Battery recycling Batteries contain materials that can harm the environment with improper disposal. Large 12 Volt storage batteries contain lead. Recycling of batteries is the preferred method of disposal. Many states require sellers of batteries to accept old batteries for recycling. Battery Instruments and controls Operation Driving 211 Instrument cluster display Practical hints Car care Technical data Index