Skip the auto shop - Our mechanics make house calls

What Is Key-Off Battery Drain?

key off battery drain

Many things in your car continue to work even after your vehicle is turned off – radio presets, security alarms, emissions computers and clocks are just a few. They continue to draw power from your car battery, and the cumulative load that these devices produce is called key-off car battery drain, or parasitic drain. Some drain is perfectly normal, but if the load goes above 150 milliamps, that’s about twice what it should be, and you could end up with a dead battery. Loads below 75 milliamps are normal.

What causes excessive parasitic drain?

If you find your battery dead in the morning, chances are it’s because something has been left on. Common offenders include under hood lights, glove compartment lights, or trunk lights that fail to turn off. Other problems, like shorted alternator diodes, can also cause excessive key off car battery drain. And of course if you forget to turn off your headlights, your battery can discharge in a matter of a few hours.

Whether the problem is key off drain, or a faulty battery, the last thing you want is to discover that your car won’t start, especially on a cold winter morning. If it does happen, though, our mobile mechanics can help. We come to you, so you don’t have to worry about having your vehicle towed. We can diagnose your car battery problem, and determine if the problem is key-off battery drain or something else within your vehicle’s charging system.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...


Related questions

Q: Battery & airbag lights come on and SUV won't start

If you said the Check Engine Light came on, I would recommend starting there. Have a qualified mechanic pull the codes from your Chevrolet Tracker using an OBD2 scanner. Any codes found will lead the mechanic in the right direction...

Q: Replaced the battery after it died. The new battery died and acts funny. All warning lights appeared on the dash; battery, brake, etc.

Hello. This sounds like an alternator problem. If the alternator is not charging the battery when the engine is running then this will occur. I usually charge the battery and start the engine. While it is running I check the...

Q: What does the Replace Battery in Remote Key message mean?

The Replace Battery in Remote Key message appears on your driver information center (DIC) when the batter in the remote keyless entry (RKE) transmitter needs to be replaced. When a new battery is added to the RKE, the DIC alert...