2009 Cadillac DTS Owner's Manual - Page 341

Vehicle Storage { CAUTION: Batteries have acid that can burn you and gas that can explode. You can be badly hurt if you are not careful. See Jump Starting on page 5-38 for tips on working around a battery without getting hurt. Infrequent Usage: If the vehicle is driven infrequently, remove the black, negative (−) cable from the battery. This helps keep the battery from running down. Extended Storage: For extended storage of the vehicle, remove the black, negative (−) cable from the battery or use a battery trickle charger. This helps maintain the charge of the battery over an extended period of time. To be sure the vent hose (A) is properly attached, the vent hose connectors (B) must be securely reattached to the vent outlets (C) on each side of the battery and the vent assembly grommet (D) must be secured to the floor pan (E). 5-37