Why Your Car Is Hard to Start — Especially in Cold Weather

It's a winter morning in Melbourne. Coffee in hand, kids in tow, you press the button and... nothing. Or worse, the slow, laboured crank of a battery struggling to find the enthusiasm for another day.

Cold mornings and car batteries have a complicated relationship. The battery was probably fine last summer. It may have been fine last week. But there's something about a cold night that exposes exactly how much battery life you have left.

KEY TAKEAWAY: Batteries don't gradually fade. They often fail suddenly — and cold weather is when they choose to do it.

Why Cold Weather and Batteries Don't Mix

A car battery produces power through a chemical reaction. Cold temperatures slow this reaction dramatically at 0 degrees Celsius, a battery may deliver only 50% of the power it produces at 25 degrees. At the same time, cold engine oil is much thicker and requires more cranking power. More demand, less supply. Winter is where weak batteries get found out.

Battery Ageing

Car batteries have a finite lifespan, typically 3-5 years in Australian conditions. As a battery ages its internal resistance increases and its capacity to hold and deliver charge decreases. A battery at 60% capacity performs fine in summer when the chemical reaction is efficient and the engine is easy to crank. Come winter, that same 60% capacity battery suddenly can't meet the higher demand. It appears to fail overnight, but it was failing for months.

Short Trips Don't Help

If most of your driving is short hops such as school pickup, servo runs, quick commutes, your battery may not be getting a proper recharge cycle. The alternator charges the battery while you drive but short trips often don't provide enough time to fully replace the charge used in starting. Lots of short starts without sufficient driving time slowly depletes the battery.

Other Causes of Hard Starting

Not every hard-start morning is the battery.

Worth checking:

• Alternator: If it's not charging properly, no battery will stay good 
• Starter motor: A single loud click suggests the solenoid
• Fuel system: Cranks normally but doesn't fire
• Corroded battery terminals

At TYREPLUS HTR, we carry a wide range of replacement batteries and we load-test them properly before recommending replacement. 

Come visit us today or call us on  (03) 9560 0442