Simple Steps to Reduce Battery Drain from an Interlock Breathalyzer

While ignition interlock devices are designed to use very little power, battery issues can still happen. Here’s how to reduce car battery problems.

Car breathalyzers, also known as ignition interlock devices (IIDs), are often required after you get a DUI conviction. IID users usually have a ton of questions about these devices, especially about how they work with your car’s battery.

This example from Reddit is just one example:

“Should u get a new car battery before getting an IID installed just to be safe? Should you get a trickler battery charger also? Just trying to prepare my car since I know an IID is in my future.”

While Reddit can certainly be valuable to crowdsource information, we thought we’d bust some myths about interlock battery drain and provide some useful tips to extend the life of your device.

While the information presented here isn’t legal or technical advice, we do have Intoxalock ignition interlock specialists who can answer any of your IID or battery questions at any time. Just reach out to our team at (888) 283-5899 for guidance.

How Ignition Interlock Devices Are Installed in Your Car

Breathalyzers installed in vehicles work by connecting to your car’s electrical system, usually through the ignition. When you blow into the device, it uses a fuel cell sensor to measure your breath alcohol content and decides if your car can start. While the IID draws power to stay ready for use, the amount is minimal.

With more than 5,200 locations, Intoxalock has the largest nationwide IID installation network in the market. That means we can answer any question. If you need your battery replaced, contact Intoxalock customer service at (888) 283-5899 to ask if there are state requirements such as reporting or documenting your vehicle’s battery service while an IID is installed.

How Ignition Interlocks Use Your Car Battery

IIDs are designed to use very little power, much less than your car’s stereo or even the clock on your dashboard. An interlock device draws this small amount of power even when you’re not driving, and that load can grow when the device’s heater runs. If you park outside overnight in freezing conditions, the heater may cycle on and off more than usual.

Most of the time, if you have battery trouble, it’s not the IID that’s to blame but an old battery or a faulty alternator.

Do Interlock Devices Cause Battery Drain Issues?

Even when your car is off, several things draw small amounts of power: the clock, radio presets, security systems, and yes, the IID. But the biggest battery problems usually come from:

• Not driving your car often enough
• Leaving lights or other electronics on
• An aging or weak battery
• Problems with your car’s alternator

Your ignition interlock device relies on your car’s electrical system to stay ready for tests. A small amount of current runs the device’s clock and memory, however that draw is usually too low to cause trouble for a healthy battery.

If you have an issue with your ignition interlock, our team of IID specialists is ready to help you troubleshoot any problems and get you back on the road safely.

Does Climate Play a Factor in Interlock Battery Drain?

If you rarely drive or live in a cold climate, a steady draw of power (however small) may contribute to car battery problems. An older battery is especially prone to losing voltage overnight.

Some devices used to keep the IID heater on standby in cold climates by cycling it several times a day. That process could accelerate power drain if the battery was already weak. Frequent short trips might not recharge the battery enough, leading to ignition interlock dead battery issues.

Four Simple Ways to Reduce Battery Drain

You don’t have to be a mechanic or comb through hundreds of Reddit threads to keep your battery healthy while using a car breathalyzer device.

Staying proactive goes a long way toward preventing car battery problems. Here are three strategies you can use right away:

1. Drive Your Vehicle Regularly

Each time you run the engine, your alternator recharges the battery. Letting your car sit for days in freezing temperatures can drain voltage. Regular trips keep the electrical system in good shape.

2. Use Sleep or Power-Save Mode

Many IID devices have a sleep or power-save mode that reduces how much power they use when your car is off. If your device has this feature, activate it whenever you park for more than a day. Check your device manual or ask an Intoxalock specialist how to use this mode.

3. Schedule Your Calibration Appointments on Time

Calibration sessions give Intoxalock a chance to update your IID’s software and perform checks. Skipping an appointment could mean missing out on the latest improvements, including any weather-related product updates. Timely interlock calibrations also help you spot possible battery issues sooner.

4. Keep Your Battery in Good Health

Make sure the battery is less than four years old and that the alternator is working well. If you notice slow starts or dim lights, have your battery and alternator tested. An older battery can lose its charge faster, especially when temperatures drop. Cleaning battery terminals and testing voltage can prevent surprises. If your battery shows signs of struggle, consider replacing it before seasonal changes.

Should You Use a Trickle Battery Charger?

A trickle charger slowly recharges your car battery and keeps it topped off, which can help prevent battery drain when your car sits unused for days at a time. This is especially helpful if you:

• Don’t drive regularly
• Live in a cold climate
• Have an older battery

Many interlock users report using trickle chargers overnight or during cold spells with good results. Nonetheless, Intoxalock recommends opting into power save mode to have the best battery results.

How Intoxalock Helps Fight Cold Weather Battery Drain

Intoxalock is actively responding to interlock device draining car battery concerns. The goal is to conserve power in cold weather for drivers who leave their cars outside overnight or in windy, low-temperature environments.

The device detects when outdoor temperatures fall below 40 degrees F. When you switch on the ignition, it runs a quick warm-up cycle before taking a breath sample. That single cycle replaces multiple short heating periods over the course of a day.

The screen will display a “WAIT” or “WARMING UP” message. After that short pause, the IID prompts you for a breath sample. You can start the engine once you pass the test. Power usage is minimal while the car is parked. The device doesn’t activate the heater in repeated intervals, so your battery preserves energy.

The next time you take your IID device in for a service or calibration, you should begin seeing the positive effects from this proactive approach.

Understanding Battery-Related Messages on Your Intoxalock Device

Our goal is to help you identify any potential issues before they become real problems. That’s why your IID displays messages when battery voltage drops. These messages let you know the battery is weak or needs attention. More details can be found in our article, Intoxalock LED Messages.

Let's look at some common alerts:

Repeated low-voltage messages often point to a battery that’s not recovering between drives. You may need to run your car more often or inspect the battery for corrosion or damage. Our article on common ignition interlock problems covers more about voltage warnings and how to manage them.

What If My Car Battery Dies?

A dead car battery can occur if cold weather, infrequent driving, damage, or an aging battery cause a full discharge. Jump-starting is usually safe with an interlock device. Best practice is to report any vehicle maintenance on your Intoxalock account before getting a battery replaced.

Remember that disconnecting your battery to do repairs or replacements isn’t considered tampering. However, a lengthy disconnection can trigger a lockout if the IID loses power for too long, so it’s a good idea to plan a quick battery swap. Longer downtime could require a service visit to reset the device.

Bonus Tips: Keep Your Ignition Interlock Battery Healthy

If you know an IID is in your future, or you already have one installed, it’s a good idea to brush up on the maintenance and service requirements for your device. Regular driving, timely calibrations, and checking for loose connections all contribute to fewer issues.

And while we understand avoiding extreme temperatures isn’t an easy solution for everyone, we’re taking proactive measures providing an additional warm-up feature for another layer of protection for cold-weather drivers.

By following these easy steps, you’ll keep your car’s battery healthy and avoid unnecessary headaches during your IID program. If you need more advice, you can learn more about how to care for your IID in cold temperatures.

Still having battery trouble? Call Intoxalock at (888) 283-5899, open the Intoxalock Mobile App for 24/7 support, or contact us.