Most vehicles are started by a 12-volt battery that turns the engine. While the car is running, the alternator recharges the battery so it can start your car the next time.
But car batteries lose power when temperatures drop below 32°F (0°C) – and even lose half their power when the temperature drops below 0°F (-18°C).
These easy-to-follow diagnostics and maintenance tips can prolong your cold-weather battery life.
How do I know if my car batteries are on the way out?
Oftentimes, it’s easy to tell if a car battery has failed: It won’t start your car. But usually, you can see the signs and replace a dying battery before it leaves you stranded or late to work.
The first step is checking the age of your car battery; you’ll see the manufacturer’s date on the battery. If your starter battery is more than three years old, be sure to have it tested and plan for its eventual replacement.
Other signs that a battery is failing include:
Your car starts slowly.
Your headlights or interior lights are dimmer than usual.
Your car won’t quite start and the engine clicks – and you have to jumpstart it with jumper cables or a portable battery pack.
If jumpstarting a battery doesn’t work, that battery is dead and ready to be replaced.
Testing a car battery
If you are unsure about your car batteries health, or if you perform in-depth maintenance: Test your battery to ensure it’s in proper working order. Flooded lead-acid batteries, which are most common in cars, can be measured accurately for specific gravity and battery voltage:
A hydrometer is required to measure specific gravity.
A digital DC voltmeter will measure voltage. (Your voltmeter should read 12.4 V or higher.)
Many repair shops, battery retailers, and auto parts retailers will also test your batteries for free.
IMPORTANT: Always consult the Safety First manual or follow your car battery manufacturer’s safety and testing procedures.
“How do I get longer life from my batteries in the winter?”
The basics include turning off interior lights and unplugging accessories when not driving. Another easy way to prolong battery lifespan is to take fewer short trips in the winter. (During short drives, the alternator may not be able to charge the battery fully – and partially discharged batteries are more prone to freezing or not having enough power to start the car next time.)
If your car is in storage and you don’t drive it during the winter, be sure to use a trickle charger to keep it charged. (Fully charged batteries can tolerate a greater temperature range than partially discharge batteries.)
Generally fully charged to lead-acid batteries will not freeze until they reach 76°F (60°C). However, the freezing temperature for partially discharge batteries is much higher.
Check your battery connections periodically. They should be in good shape, secured tightly to the hold-down bar, and clean. While wearing personal protective equipment, you can remove corrosion with a stiff wire brush. (Again, see Safety First for step-by-step instructions and safety tips for car battery maintenance.)
Need a new battery?
One of the most important factors to consider is a car battery’s Cold Cranking Amps (CCA). CCA is a measure of how many amps a battery can deliver for 30 seconds at 0°F, while not dropping below 7.2 V. Replacing the battery in your vehicle with the same or higher CCA rating as the original battery is critical for reliable performance.
All Crown Battery automotive starter batteries are at least 500 CCA, to ensure optimal performance during the winter.