All newer cars have way too many unnecessary computers. Unless the manufacturer specifies differently, the industry standard is 35 milliamps is the maximum current drain to keep the memories alive in those computers that have them. Mainly that's the Engine, Transmission, and Body Computers as well as the radio. At 35 ma, a good battery will still start the engine after sitting for three weeks. Chrysler, for example, guarantees that but in actual practice you may find the battery will last twice that long. A few models allow up to 50 ma. Current drain.
As the battery ages, some of the lead flakes off the plates and the reserve capacity goes down so you may find the engine only starts after sitting for two weeks.
All cars have a means of disconnecting non-essential functions for shipping from the manufacturing plant to their storage facilities. On older cars that was often a bullet connector in a smaller positive battery cable. Later models used a fuse under the hood. You may also find one or two fuses inside the car. They commonly have pull handles to facilitate removal when the car will be stored.
Sunday, April 15th, 2012 AT 10:34 PM