Batteries and Winter Driving

February 9th, 2017

One crisp, cold morning you go out to start your car and it turns over slowly…then slower…then slower…and then you hear that dispiriting “click…click…click” noise that means you’re not going anywhere. 

Why is cold weather so much harder on an automotive battery?Car Battery in Montgomery AL

Automotive batteries haven’t changed much in 80 years. They’re comprised of several cells wired together in series; with six cells producing 2.1 volts, it adds up to 12.6 volts at full charge. Each cell contains lead plates acting as a cathode, sulfuric acid as an electrolyte solution, and lead dioxide plates to act as an anode. When the battery discharges, the acid in the electrolyte reacts with the lead plates and changes their surfaces to lead sulfate. As the battery charges again, the chemical reaction reverses and lead sulfate returns to a lead dioxide material.

Any battery that can be recharged, whether it’s in your car, phone or laptop, can only stand so many charge/discharge cycles before it starts to weaken and can’t hold or deliver a charge as well anymore. Along with that fact, the chemical reaction in an automotive battery slows down considerably as the temperatures drop; at 35 degrees, your battery can only hold and deliver half the cranking amps it can at 70 degrees.

Now, consider your motor oil for a moment.

Conventional motor oil formulations tend to thin out in hot weather and thicken and become more viscous at cold temperatures. This is bad for the engine, as oil needs to quickly circulate to the camshafts, bearings and valvetrain components at startup. It’s also making your battery’s job and your starter’s job a lot harder in trying to crank the engine.

Before the snow starts flying, it’s a really good idea to have your battery checked thoroughly. That means:

  • Checking the alternator and drive belt for proper tension or excessive wear
  • Cleaning the battery terminals, posts and cable clamps of corrosion
  • Checking the battery’s cold cranking amp capacity, both under a load test and with a meter

You don’t want to get stranded this winter…so if your battery’s already starting to weaken, you might be better off just buying a new battery. Make an appointment with us at Don Duncan’s All American Auto & Tire Centers – we’ve got top brand batteries at great prices! 

  Posted in: Auto Repair 101