The battery in my 2011 Ford Fusion has been randomly dying. I recently replaced it, but the problem didn’t go away. It takes a long time for the battery to completely die, so I'm not sure what is causing the problem. The car has less than 50,000 miles on it, so it’s not like everything is falling apart. What could be causing my battery to die?
Nothing is quite as frustrating as stepping out to start the day, putting your key in the ignition and… silence. In many cases, the solution is as simple as replacing the battery. As you have discovered though, sometimes your dead battery is only a symptom of a larger problem. In most modern vehicles, the Fusion included, systems in the vehicle are routed through a body control module (BCM) or in your case, a smart junction box (SJB). These components typically utilize a timer that prevents accessories from staying on and draining the battery. However, in some circumstances, lights or modules can remain active or “awake”, killing the battery in a relatively short period of time. Now that battery number two has not solved your issue, I would advise you have a qualified technician examine the starting/charging system to ensure you do not have a defective battery. Once the integrity of the battery has been confirmed, the technician should conduct a battery draw test. Basically, the technician will eliminate circuits one by one while watching an ammeter connected to the battery. When the excessive current draw has been eliminated, the suspect circuit can be more easily identified. Electrical problems such as this have too many variables to provide an accurate estimate of the cost to repair here. However, a competent technician can typically identify the issue within one to two hours, provided the issue can be duplicated at the time of inspection.
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