The Cold Hard Truth About Winter Batteries
There's nothing worse than turning the key on a cold winter morning and hearing that dreaded slow crank... or worse, nothing at all. If you've ever been stranded with a dead battery, you know the frustration. But why does this happen so often in winter?
The Science: Cold Kills Battery Power
Car batteries are electrochemical devices. The chemical reactions that produce electricity slow down dramatically in cold temperatures.
- **At 0°C:** A fully charged battery loses about **35%** of its cranking power.
- **At -18°C:** It can lose up to **60%** of its power.
- **Meanwhile:** Your engine needs **more** power to start when cold because the oil is thicker.
It's a double whammy—less power available, more power needed.
Why Batteries Die in Winter (Not Summer)
Here's the thing: heat actually damages batteries more than cold. Summer heat accelerates internal corrosion and evaporates electrolyte fluid. But you don't notice because warm engines start easily.
Come winter, that weakened battery can't deliver the goods. The cold exposes the damage that summer caused.
Warning Signs Your Battery is Dying
Don't wait for a no-start. Watch for these symptoms:
- 1.**Slow cranking:** The engine turns over sluggishly, especially on the first start of the day.
- 2.**Dim lights:** Headlights or interior lights seem weaker than usual.
- 3.**Dashboard warnings:** Battery or charging system light illuminates.
- 4.**Age:** Most batteries last 3-5 years. If yours is older, it's living on borrowed time.
- 5.**Corrosion:** White or greenish buildup on the battery terminals.
Prevention Tips for Auckland Winters
1. Get Your Battery Tested A simple load test tells you exactly how much life is left. We can do this at your home or workplace in minutes.
2. Clean the Terminals Corrosion creates resistance. Clean terminals with a wire brush and apply dielectric grease to prevent future buildup.
3. Limit Short Trips Short trips don't give the alternator enough time to fully recharge the battery. If you only drive short distances, consider a trickle charger.
4. Turn Off Accessories Before Starting Heated seats, radio, lights—turn them all off before you start the car. Let all available power go to the starter motor.
5. Park Undercover A garage or carport keeps your car a few degrees warmer, which can make all the difference.
When to Replace
If your battery is over 4 years old and showing any warning signs, replace it before winter hits. A new battery costs far less than a tow truck and the stress of being stranded.
Mobile Battery Replacement
At Mobile Autoworks NZ, we come to you with a range of quality batteries. We'll test your old one, fit the new one, and dispose of the old battery responsibly—all in your driveway.
Don't get caught out this winter. Book a battery check today.