Presented by Dan Ritchie:
A vehicle owner who discovers a dead battery will generally that the battery or the alternator needs replacing. While these suspects often turn out to be true culprits, there may be other gremlins at work. Modern automobiles are outfitted with all manner of gadgets and electronic processors that draw energy from the battery that draw energy from the battery when the vehicle is turned off. This bye of “parasitic loss” is exemplified by such electronic accessories as car radios. Which need electricity to retain information about preselected stations. Usually, collective parasitic losses do not amount to enough lost power to fully drain a battery, even over several weeks. However, if a stuck relay leads to unacceptable losses, it must be diagnosed and repaired.
At Express Auto Service, we recommend regular maintenance inspections to help identify and perform needed services. If you have a question or concern about your vehicle, please stop in for a free visual inspection or brief road test.
HINT: One method auto technicians use to identify batter drain when a car is not turned on is to measure for parasitic current draw about 50mA