2008 Mercedes SL-Class Owner's Manual - Page 428

Practical hints Batteries Batteries For more information on batteries, see "Battery" ( page 290). Your vehicle is equipped with two batteries: The starter battery The battery for electrical consumers (consumer battery), located in the trunk The starter battery is located on the right-hand side of the engine compartment. ! The starter battery, its filler caps, and the ventilation hose must always be securely installed when the vehicle is in operation. The consumer battery is located on the right-hand side of the trunk. ! The consumer battery located in the trunk is a valve-regulated lead acid (VRLA) battery, also referred to as "fleece" battery. Such batteries do not require topping-up of the electrolyte level. VRLA batteries therefore do not have cell caps and the battery cover is non-removable. Do not attempt to open the consumer battery as otherwise the battery will be damaged. Even though VRLA batteries do not require topping-up of the electrolyte level and cannot be opened to check the electrolyte level, the battery condition must be checked periodically by performing a battery conductance test. Refer to Maintenance Booklet for battery condition testing intervals. As with any other battery, disconnect the consumer battery if you do not intend to operate your vehicle for an extended period of time to prevent battery discharge or connect an accessory battery charge unit expressly approved by Mercedes-Benz for your vehicle model to maintain the battery charge. Contact an authorized Mercedes-Benz Center for further information. 4 Positive terminal 5 Negative terminal 1 Positive terminal 2 Negative terminal 3 Battery ventilation 427