How Parasitic Drain Affects Your Car Battery

If your car’s turned off, you might assume your battery’s off as well. That’s not the case. The battery is affected by a parasitic drain, in which small amounts of current are used.

What causes parasitic drain?

In nature, a parasite is an organism that gets its food from or at the expense of its host. In your car, any number of systems could be “feeding” off of your battery.

Today’s cars feature hundreds of electronic systems, a number of which require a constant supply of milliamps of current.

Your vehicle’s memory seats, internal clock, GPS system, 12V outlet, mirrors, alarm system, engine computer, radio, and lights could all be drawing from your battery.

In newer vehicles, a parasitic drain of 50-milliamps to 85-milliamps is considered typical. For older vehicles with fewer electronics, a drain of less than 50-milliamps is normal.

What’s the Danger of Parasitic Drain?

If a battery goes long periods without being recharged by the alternator, those tiny milliamps drawn by parasitic devices will kill it.

Even normal parasitic drain, also known as “key-off drain,” puts wear and tear on a battery. If a battery drops below 12.4 volts, sulfation begins to set in. 

Sulfation is a buildup of lead sulfate crystals. This occurs when a battery is deprived of a full charge (also called “killing the battery” or “draining the battery”). Sulfate materials crystallize on the discharged portions of the battery plates, damaging the battery.

All lead-acid batteries accumulate sulfation over the course of their lifetime, as a part of the natural chemical process. The problems occur when sulfation builds up.

Allowing a battery to go dead for long periods of time will cause sulfation. 

CTEK chargers help preserve your battery

Maintaining your battery helps maximize its life. A CTEK battery charger does just that. Through the application of a series of 4 to 8 patented charging and maintenance stages using unique microprocessor-controlled charging processes. 

When required, the CTEK charger automatically takes appropriate action based on your battery’s needs: reviving, charging, conditioning, desulfation, and maintaining your battery. 

CTEK chargers will constantly monitor the condition of your battery and act as needed to keep it at peak capacity. CTEK Chargers regulate the charge voltage to protect sensitive and expensive vehicle electronics. 

Certain CTEK chargers have a special reconditioning or RECOND mode that helps to revive batteries that have been sitting unattended for long periods and are deeply discharged. 

Once the charger is connected, you can forget about how long the battery needs to be charged or whether it is sulfated or not. Our chargers take care of everything automatically so that you can enjoy the work or pleasure that your battery was destined to provide. We call it ”Connect and Forget.”

Check out our complete line of smarter battery chargers. To find out which CTEK charger is right for your vehicle, use our Charger Selection Tool.