A local mechanic is warning people against jump-starting a dead car battery during a cold snap.
Tony Zobott, owner of Auto Authority, 765 Duffy Drive, Crystal Lake, said car batteries are complex devices that often struggle to perform in below-freezing temperatures. He said jump-starting them in the bitter cold carries the risk of explosion.
“If someone tries to jump-start a frozen battery, it can explode on them, shooting acid or sharp metal,” Zobott said, adding that he’s been inundated with requests for help this week from residents. “If your battery’s dead, it’s frozen. Don’t try to jump-start it. ... Take it into the house to thaw and charge it before you put it back in.”
He also recommended against repeatedly starting a vehicle throughout the day and night. By constantly starting a car, Zobott said, drivers are inadvertently depleting the car battery of valuable cold cranking amps.
A discharged battery is highly susceptible to freezing, he said, and alternators do not replenish batteries while sitting idle. Alternators also can overheat, he cautioned.
“We see a lot of bad advice on the internet about starting your car every couple hours,” he said. “It actually works against you. ... When you start your car, you deplete your cold cranking amps. Idling the car or doing a short trip is not sufficient to recharge the battery.”
Before starting a vehicle, Zobott said to turn on the headlights for about 15 to 30 seconds.
He said this allows a weak current to flow through the battery, which causes a chemical reaction that will warm the battery and temporarily raise cold cranking amps. However, moderation is key. If the lights are on for too long, the battery will weaken.
Zobott also recommends drivers closely monitor tire pressure because the cold can affect tire pressure.
“As we get colder, tire pressure lowers,” Zobott said. “As they lose air, you get less tire contact with the road. ... Rubber isn’t made for this cold.”
It’s also crucial to keep a full tank of gas, Zobott said, because it prevents condensation from building up in the tank and helps stabilize the vehicle.
“A full tank of gas covers a lot of things,” he said. “You don’t want there to be any space in that fuel tank for any moisture to freeze. Having a full tank eliminates the space for condensation.”