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Main Street Mechanic, Established 2005

Dead Car Batteries in Winter - How They Work, How To Prevent Them, and What To Do

Since the beginning of (car) time, cold weather and car batteries have had a complicated relationship. The main job of a car battery is to start the engine. Once the engine is started, the alternator takes over to run the vehicle’s electrical systems. Once the car is turned off, the battery gives power to the car and can come discharged quite quickly.

So what happens to a car battery in cold weather? The battery in your car has positive and negative electrodes. There are several thin plates inside each cell that work together to create 12 volts, the result of a chemical reaction happening inside each cell. Cold temperatures slow down the chemical reaction, causing vehicles to use up to twice the current as normal to start the engine. This can shorten the battery life and make it more difficult for your vehicle to start.

How To Optimize Car Battery Life in Winter

There are some simple things you can do to minimize the risk of experiencing a dead battery in winter. To start, purchase a battery designed to function in colder temperatures. The label should list a high number of cold-cranking amps. These types of batteries are readily available online and in car stores.

Make sure to check the voltage on your car battery once temperatures start to drop. Especially if the battery is three or more years old, it’s important to have the voltage inspected. A fully charged battery won’t start freezing until more than -40 degrees, but an older, weakened battery can start freezing at 32 degree Fahrenheit.

If having your car be dependable and operational at all costs, it’s recommended that you replace your battery every few years as a preventive measure. Replacing the battery is a relatively inexpensive way to ensure the vehicle will turn on and work reliably no matter what.

What To Do If Your Car Battery Won’t Start

Once temperatures start to drop, it’s a safe bet that there will be many car batteries that won’t start. Being stuck in cold temperatures with wind chills, unable to get to where you need to go, is one of the worst feelings that can happen. Make sure to do all preventive car and inspection beforehand to avoid this uncomfortable and irritating experience. However, if you find yourself stuck with a dead battery, make sure to prepare ahead of time by having blankets, water, food, and jumper cables in the car. If possible and easily accessible, first try jumping your car. Park the running car as closely to yours as possibly, preferably head-to-head, and switch off the ignition. Connect the positive jumper cable to the positive terminal and the good battery  and then the positive terminal on the dead battery, followed by the negative connection.

Once connected, with the other car on, try to start your car. If the car doesn’t start after several tries, it’s time to call a tow truck. Main Street Mechanic provides a tow service, as well as a free customer shuttle to get you where ever you need to go.

Keep in mind that freezing weather drains your car battery power by 30-60% by slowing down the electrochemical reaction. If your car battery is over 3-4 years old, replacing it sooner rather than later can help prevent these annoying (and sometimes dangerous) inconveniences.

Furthermore, it’s important to remember that summer can also damage your battery, leaving it more susceptible to the damages of cold weather. Hot temperatures and summer heat can cause internal battery corrosion and evaporate the electrolytes that your battery relies in. As the weather becomes colder, your battery doesn’t have the structural integrity to manage the additional stress of cold temperatures.

You can be prepared by addressing corrosion and having a technician clean or replace your corroded terminal ends. Keep up with oil changes and maintenance on the recommended schedule. Park your car in your garage and cover your car overnight to lock on some of the heat and protect your vehicle from ice.

Minimize battery usage by turning off your car lights when not in use and unplug any chargers to minimize battery depletion. Give your battery more time to recharge by taking your car for a longer drive every once in a while.

Take advantage of our $9.99 Winter Inspection Special valid from now until November 15 to ensure there are no unexpected problems that arise this winter and get ahead of any minor inconveniences and major repairs down the road. Whether you need help dealing with battery corrosion, replacing your car battery, or getting a tow and ride if your vehicle dies, Main Street Mechanic is here for you and happy to help! We proudly offer transparent pricing and coupons to make our vehicles services as reliable as possible. Make your appointment online or give us a call to get started today!

Box CarMain Street Mechanic




7:30 AM - 6 PM


337 West Main Street
American Fork, UT 84003