How Do AGM Batteries Perform in Cold Weather?

For much of the country, winter weather is on the way. As the temperatures plunge, the likelihood of your auto battery dying on you increases significantly. Learn how cold weather impacts your vehicle battery and why you might want to invest in an AGM replacement.

How Does Cold Weather Affect a Car Battery?

Winter weather puts an enormous strain on your vehicle’s battery. The cold causes it to discharge more quickly, reducing the amount of power it has available to turn over your engine. At the same time, these low temperatures are also slowing down the chemical reactions that take place inside your battery and thickening the oil in your engine. That means your battery has to work much harder to turn over your engine and has less energy than normal to do so.

What are Cold Cranking Amps?

Cold cranking amps (CCAs) measure the amount of electrical current a battery can discharge and sustain for at least 30 seconds at 0°F while maintaining the terminal battery voltage of 1.2 volts of current per cell. So, what exactly does that mean? Basically, CCAs help you determine how well your battery will perform in a cold environment. The higher number of CCAs your battery has, the more power it can deliver in order to compensate for the impact of the cold.

What is an AGM Battery and How is It Different from a Lead Acid Battery?

Most cars come with a 12 volt flooded lead acid battery, but as technology moves forward, more and more models are relying on AGM batteries. A lead acid battery is divided into six separate cells. In each cell, positively and negatively charged plates are stacked in an alternating pattern with a plastic separator between them. Within each cell, these plates are immersed in a liquid acid solution called an electrolyte, which creates a path for electricity to flow.

AGM (short for Absorbed Glass Mat) batteries are constructed a bit differently. They’re still divided into individual cells, each of which contains alternating positive and negative plates. In an AGM battery, however, the separator is a non-woven microglass-mat material that absorbs the electrolyte and keeps it suspended in place. The mat contains enough electrolyte for the battery to deliver its full capacity and also allows it to be mounted in a variety of positions without fear of spilling.

Are AGM Batteries Good in Cold Weather?

AGM batteries perform much better in low temperature environments than flooded lead acid batteries do. For starters, AGM batteries typically have higher CCA ratings than a flooded lead acid battery. They also have a slower discharge rate than lead acid options, meaning they do a better job of holding a charge. AGM batteries also recharge faster and are more resistant to cold weather damage. Since the electrolyte is held in the glass mat separators, it won’t expand when frozen like it will in a flooded battery. This helps prevent the plates from cracking.

Will a Dead AGM Battery Freeze?

Yes, even though they perform better than flooded lead acid options, an AGM battery can still freeze. The best way to prevent this is by keeping it fully charged. In a discharged battery, when the voltage decreases, the electrolyte inside it begins to change from acid to water. The more watery the electrolyte becomes, the easier it is for it to freeze.

If you drive your vehicle at highway speeds on a regular basis, you don’t have much to worry about. Your alternator will charge your battery after about 30 minutes of driving. If you only use your car for short driving trips or leave it sitting for long periods of time though, you might want to invest in a charger.

What is the Best Charger for an AGM Battery?

When shopping for any type of battery charger, be sure to select a model that matches the voltage and chemistry of your battery. The X2Power 7.5 Amp Charger is compatible with both 12V and 24V batteries and has different charging settings for flooded, gel, lithium and AGM batteries. Even better, it will automatically shut off once your battery is fully charged, to prevent it from overcharging.

Batteries Plus Has Everything You Need to Care for Your Car

Before the temperature drops, it’s a good idea to have your battery checked to make sure it’s healthy enough to withstand another winter. Stop into one of our 700+ locations and have it tested for free. Shopping for a new battery? Read about our Top 4 Best Replacement Car Batteries, then check out our selection of truck and auto batteries online. We also offer free installation on most makes and models at most of our locations.

Looking for answers to your additional automotive questions? Our blog has plenty of useful information. Learn “What Should Be In My Vehicle Emergency Kit” or read about the “6 Easy Steps To Jump Start Your Car.”