If your car struggled to start Tuesday morning amid Pittsburgh's bitter temperatures, you're not alone. AAA says dead batteries are the number one reason drivers are calling for help during this cold snap. 

"On days like today, calls to AAA go through the roof and largely, if not primarily, for dead batteries," said Jim Garrity with AAA.

AAA says extreme cold can cut a battery's power in half while the engine needs even more energy to start, leading to a surge in roadside assistance on days like Tuesday.

Jim Garrity with AAA says the cold slows the chemical reaction inside the battery, cutting the power it can deliver.

"It's actually the heat during the summer that disrupts those internal components of the batteries and it's mornings like this morning that are just too much for the battery to bear," Garrity said. "The heat does the damage and the cold mornings, it's the battery finally giving up." 

AAA says that's when calls spike as batteries fail at the exact moment cars need the most power. That combination is why dead batteries are the number one reason drivers call for help during winter cold snaps, with January consistently one of the busiest months.

"When it comes to dead batteries, it is something that you should expect when you have a vehicle, especially if that battery is two or three years old," Garrity said. "Cause if you're expecting it, that means you're going to actually get it tested. It should be a routine annual thing you do."

When calls surge like they did on Tuesday morning, Garrity says drivers may be waiting longer for help, so having a few basics in your car can make a big difference. Garrity suggests things like blankets, a flashlight, snacks and water, a phone charger, a portable jump-starter and your medications, just in case you're waiting longer than anticipated.

"If all of us were in this car and we were sitting here for a while, what would we need to keep ourselves safe and what would we need to keep ourselves comfortable?" Garrity said. 

AAA says slow starts or dim lights are warning signs your battery may be failing, and replacing it before the next deep freeze could save you from being stranded.