Modern cars are full of electronics. When a particular system malfunctions, it can create a small but constant electrical drain on the battery. For a technician, these problems can be some of the most difficult and exasperating to solve. Fortunately, they are relatively rare.
Sensitive electronics control almost everything in your car. Engine management and interior amenities such as the touchscreen and digital gauges are run via computer modules, as are all interior lights, windows and locks. When all of these are working properly, the car and battery are performing as intended. When something isn’t, it can mean trouble, and corroded or damaged switches can make things worse. These problems can cause what’s called a parasitic draw, which happens when something causes electrical current to flow through the circuit, either constantly or intermittently. An electrical contact that has developed corrosion can cause this, as can a malfunction in a circuit board or microprocessor. Also, the drain rate can vary, resulting in a dead battery that occurs after weeks or hours.
If the charging system and battery are checked, you need to make sure nothing is turned on, such as an interior light that stays on overnight. If that doesn’t reveal the problem, you’ll need to have your car looked at by a qualified technician. Unfortunately, this can be time-consuming and expensive, although if you’re lucky, a simple computer scan can show the error right away.
