Ask The Beaverton Car Guy: Maintaining Your Car’s Battery During Cold Weather

By Larry “The Car Guy“ Ferguson


Hello Beaverton Readers,

Over the last week or so with the weather getting colder, a few of our residents have emailed about having a dead or low battery in their cars. Here is some useful information about auto batteries.

Freezing temperatures can affect your car battery.

Dead or dying batteries are always the biggest reasons for roadside assistance calls during a cold snap. One of the main culprits are the “always-on” electronic devices plugged into the vehicle’s cigarette lighter socket. The Auto Club warns “In frigid weather, weak car batteries are the first to go, so it’s worth having your battery checked.” At 0°F, a car’s battery loses about 60 percent of its strength and at 32°F it loses 35 percent. During cold temperatures starting an engine can take up to twice as much current as needed under normal conditions. It is advisable to have your battery tested, as well as your starting and charging systems prior to the deep cold of winter.

Replace an old battery

“The life span of an automotive battery has historically been defined as 3-5 years. However, with the increase in electronics within vehicles, the full life is moving a lot closer to 3 years. “Surprisingly, although heat causes more damage to batteries than cold weather, starting a vehicle in cold weather puts more strain on it. The cumulative impact of various factors over time allows cold weather to ultimately end the useful life of a battery.”

Warning signs that you are at risk for a battery related breakdown include:

  • You hear a grinding or clicking sound when you turn on the ignition,
  • Your vehicle cranks slowly when attempting to start.
  • Your headlights dim when idling but brighten when the engine is revved.
  • Your battery is more than three years old.

Battery basics

Car batteries are an electro-chemical process so they have inherent limitations and are impacted by endless variables impacting their performance. For example, the life of a battery depends on the climate you live in, length of time electronic accessories are plugged into your vehicle, and how far and often you drive your vehicle.

While three to five years is a typical life span, various internal and environmental conditions impact a battery’s long term health. Periodic inspection, testing, and cleaning are suggested and monitoring the use of accessories and electronic devices when your car is not running can help maximize its longevity. When your car is not running, the battery continues to supply power to the clock, the anti-theft system, and the other conveniences in modern cars. Accessories, like smartphones and tablets, can add to the drain.

“Unplug mobile phones, tablets, chargers and other electronic devices when you don’t need them, especially when the car is turned off,” says Reynolds. “While the car battery does not ‘run down’ immediately if a device is being charged while the engine is not running, it’s capacity over time can decrease from the cumulative effect of multiple devices drawing current from it.”

Why do car batteries die?

It is a fact of life: cold weather is a battery killer. Make sure the battery terminals and cables are securely attached and free of corrosion. A load test performed by a qualified technician will help determine if a car’s battery is strong enough for cold weather starts.

A very special thanks to all of you who reached out to me. If you have a question or need automotive advice please contact me.

Larry’s specialty is locating cars, even hard to find cars, for everyday folk. He has been in the automotive industry for over 35 years and has several degrees in automotive technology. Email him at or call 503-930-1493