Car Battery Died with Interlock: What Should I Do?

Car Battery Died with Interlock

Having a car interlock installed is for your safety and that of others (other drivers and pedestrians). It also helps to reduce the number of intoxicated drivers and accidents.

Interlocks are an electronic device that needs an electrical power source to operate, the power needed is usually drawn from the car battery.

As low as ¼ amp is drawn per time compared to other accessories in the car, this amount is not enough to drain a car’s battery except under certain conditions. An interlock can cause a car battery to die if the car has been idling for a long time, or the battery is in a bad condition, etc.

In the event that your battery died because of an interlock, you may want to recharge to see how it performs and rule out some assumptions. Or you seek the help of a professional if you can’t seem to find a solution.

What is a Car Interlock?

A car interlock is also known as ‘Ignition Interlock Device’ or ‘blow and go’. It is a device installed in the car that ensures a breath alcohol test is taken before the car can start.

The device has a pre-set limit which determines if the vehicle will start or not, the car won’t start if the driver’s breath test is above the pre-set limit but will start if it’s below the limit set.

The test is usually carried out by blowing air into the mouthpiece on the device and the device, in turn, analyzes the breath for alcohol.

Depending on the laws of the state you are resident, you will have to service the car interlock every 30, 60, or 90 days. Also depending on the state, your interlock may have a camera or not.

The device is designed in a way that allows you to be prompted to take another test after you must have started the car. This is to ensure you haven’t taken any alcohol after starting the car and it is usually done by pulling over on a side of the road.

Can a Car Battery Die with Interlock?

No, a car battery cannot die with a car interlock but not impossible. The car interlock like all other accessories in the car draws power and electricity from the battery, but unlike other accessories, the electricity drawn by the interlock is very minimal and the impact may hardly be felt on the battery.

If by chance your car battery dies while the interlock is installed or in use, it may have absolutely nothing to do with the interlock.

What Happens if a Car Battery Died with Interlock?

In the event that a car battery died with interlock, it may not be as a result of the amount of electricity drawn by the interlock and it can as well be related to it.

A bad car interlock may use up more than the required power over time, interlock whether taking a breath test or not draws power from the battery but the amount drawn while the car is idling is usually less than when it is running. When you have a bad or faulty interlock, the chances of it draining out your battery over time is high.

A battery can die with an interlock if the battery itself is not in good condition. Batteries with use over time tend to wear out resulting in reduced performance.

When the battery is not in good condition you may experience a problem when you try starting the car after you must have taken a breath of alcohol concentration.

If you have not been in tune with the condition of your car battery before then, you are likely to think the interlock is the reason why the battery went out.

Idling for a long period has a negative effect on a battery, when a car is idling, the interlock and other accessories draw minimal power from the battery.

This constant drain on the battery without charging will also prevent the car from starting. It is advisable that you take the car out once in a while even when idling, this way the battery gets some charge time often.

Before the installation of a car interlock, you should check and be sure the car battery is in good condition and also able to handle the addition of an interlock.

What to do if a Car Battery Dies with Interlock

If a car battery dies with an interlock then you should find out why it happened. Interlock usually does not drain a car’s battery to the point of dying, so if it happens there will be a reason.

  • First, you should recharge the battery and see if the problem persists. If it doesn’t then the battery was probably low before you used the interlock and the interlock just used the last of its power.
  • If the car battery dies after you must have recharged then the battery has a problem and should be checked out.
  • You should check the battery and interlock to know if they are both in good condition or if it needs replacing or repair.

Be sure you don’t leave the car idling for too long without charging the battery or leave the car running when you are not inside. All these and more may cause a car to die when you use the interlock. The battery may not charge itself while idling.

Disadvantages of Car Battery Dying with Interlock

Although it has been established that the chances of an interlock damaging your car are low but also possible, there are some disadvantages to having your car battery die as a result of an interlock. They are:

  • You Could be Penalized: After a breath test must have been taken by the driver before starting the car, drivers are in some cases required to re-take a test while driving. This won’t be possible if the car dies and may be recorded as non-compliance. The driver may be faced with a penalty for non-compliance by law.
  • Get Stranded: The car battery may start and run for some miles before going off. It will be a very bad situation if the battery dies in a deserted place or an area where it will be hard to get help thereby leaving you stranded.


It is important to note that an interlock can damage your car if it wasn’t installed well, therefore it is better to employ the service of an installer that knows what they are doing.

Do not miss appointments to get the car interlock calibrated or serviced, by doing this you save yourself from costly damages that may be done to the car.