Cold, Wet Winters and Flat Batteries on the Limestone Coast

This guide is for anyone around Mount Gambier, Millicent and Penola whose car, ute or farm vehicle seems to find winter harder than the rest of the year. It explains why cold, damp weather is tough on batteries and charging systems, how to tell a weak battery from a different fault, and what to check before the worst of winter arrives.

How can we help?

Need it fixed?

Get a quote from a local Cold, Wet Winters and Flat Batteries on the Limestone Coast auto electrician, for anything from a flat battery to a full fit-out.

Get a quote

Buying parts?

Quality auto electrical parts from Ozautoelectrics, an established Australian supplier since 2010, dispatched through a nationwide network. For retail and trade buyers.

Shop parts

Doing it yourself?

Free step-by-step guides written for South Australia conditions, with the parts you’ll need listed for each job.

Browse DIY guides

Auto electrician in Cold, Wet Winters and Flat Batteries on the Limestone Coast?

Are you an auto electrical business? List your business on this site.

List your business on this site

What a Mount Gambier winter does to a battery

Mount Gambier's winters are cool and wet. The Bureau of Meteorology's long-term averages for Mount Gambier Aero show a mean July minimum of about 5°C, and around 119 days a year with at least 1 mm of rain. The wettest months are in winter. Overnight, cars parked outside sit in that cold and damp until someone tries to start them.

A lead-acid battery makes power through a chemical reaction, and that reaction slows down as the battery gets colder. At the same time, cold engine oil is thicker, so the starter motor needs more current to turn the engine over. Less supply and more demand is why a battery that seemed fine in March can fail on a frosty June morning. The battery was already worn. Winter simply found the weakness.

Winter loads add up

Think about a typical winter drive across Mount Gambier. The headlights are on because it's dark or foggy. The heater fan runs on high, the rear demister is on, the wipers are going and the seat heaters may be on too. All of that draws on the electrical system before the battery has had a chance to recover from the start.

On a long drive the alternator can keep up. The trouble is that most trips around town are short. Five or ten minutes is often not enough to replace the energy used to start a cold engine, especially with every winter load switched on. Do that twice a day for weeks and the battery slowly runs down, until one morning it can't crank the engine at all.

• Switch off the rear demister once the glass is clear. It is one of the bigger loads in many cars.
• Turn the heater fan down once the cabin is warm.
• Make one longer drive each week, such as a trip out to Millicent or Penola, to give the battery a proper charge.
• If the car mostly does short trips, use a smart charger overnight every week or two.

Damp gets into connections

Cold is only half the story. Long periods of rain and damp mean moisture finds its way into plugs, earth points and battery terminals. Corrosion builds up slowly and adds resistance, so less current reaches the starter and less charge gets back into the battery. A clean battery with a corroded earth strap can behave just like a flat one.

Look at the battery terminals for white or green crust, and follow the main earth cable from the battery to the body and engine. If any of these look tired, clean them back to bright metal and protect them. Tail lights and number plate lights also take in water during long wet spells. If a lens has condensation inside, the seal has failed and the globe holder will corrode.

Battery, starter or alternator?

When a car won't start on a cold morning, the battery gets the blame first. Often that's right, but not always. A slow, laboured crank points to a weak battery or poor connections. A single click with no crank can mean a flat battery, a bad connection or a starter fault. A car that starts after a jump but is flat again the next morning may have a charging fault or something draining the battery overnight.

Before you buy a new battery, get the old one tested properly. A voltage reading alone doesn't show how well a battery copes under load. Our guide how to test a car battery explains the difference between a simple voltage check and a load test. If the battery tests healthy, the next step is to check the alternator's output and look for any drain with the car switched off.

Choosing a battery for a cold climate

When you replace a battery, the cold cranking amps (CCA) figure matters more here than in a warm city. It tells you how much current the battery can deliver in cold conditions. Use at least the rating your vehicle maker specifies, and check the battery's physical size, terminal layout and type match too.

Many newer cars with stop-start systems need an AGM or EFB battery, and fitting a standard flooded battery in their place can shorten its life and upset the charging system. Some vehicles also need the new battery registered with the car's computer. Our guide car battery types explained covers the main types and where each one is used.

Farm and spare vehicles in winter

Around Millicent and Penola, plenty of properties have a second ute, an old tractor or a farm bike that gets used now and then. In winter these vehicles sit in cold, damp sheds for weeks. Their batteries discharge on their own, and a battery left flat in the cold can be permanently damaged.

A battery maintainer connected to a properly installed shed outlet is the simplest fix. If there's no power, disconnect the negative terminal while the vehicle is parked, and recharge it before use. Any new fixed 240V wiring in the shed is a job for a licensed electrician.

Jump starting safely in the cold and wet

If you do need a jump start on a wet morning, take your time. Make sure both vehicles are off before you connect the leads, keep the clamps from touching each other, and connect the final negative lead to a solid earth point on the engine block or body away from the battery. Never try to jump a battery that is cracked, leaking or frozen. Our guide how to jump-start a car safely covers the full sequence.

A jump start gets you going, but it doesn't fix the cause. If you needed one, have the battery and charging system checked soon after.

Your pre-winter checklist

Autumn is the time to do this, while the days are still dry and mild. If you find a problem, auto electricians around Mount Gambier and Millicent can test the battery and charging system and track down any drain.

• Have the battery load tested, especially if it is more than three or four years old.
• Clean and protect the battery terminals and the main earth strap.
• Check every exterior light, and look for water inside the lenses.
• Make sure the rear demister, wipers and heater fan all work on every setting.
• Fit a battery maintainer to any vehicle that will sit for the winter.

Parts for this job

Order quality parts online from Ozautoelectrics, dispatched Australia-wide.

Get it done: get a quoteDo it yourself: shop car batteries

Get it done: get a quoteDo it yourself: shop battery maintainers

Get it done: get a quoteDo it yourself: shop battery terminals

Get it done: get a quoteDo it yourself: shop jumper leads

Questions Mount Gambier drivers ask

How long should a car battery last in Mount Gambier?

It depends on the battery type, the vehicle and how it is driven, so there is no single answer. Batteries in cars that mostly do short trips around town tend to wear faster than those that do regular long drives. Instead of going by age alone, have the battery tested each autumn and replace it when the test shows it is weakening.

Why does my car only struggle to start after rain?

Moisture may be getting into a connection. A corroded earth strap, a damp starter motor connection or a cracked battery cable can work fine when dry and fail when wet. Look for corrosion at the battery, the main earth and the starter. If it keeps happening, an auto electrician can test voltage drop across each connection to find the weak point.

Should I leave my car's battery on a charger all winter?

Use a smart charger or battery maintainer designed to be left connected, not an old manual charger. A maintainer watches the battery's voltage and only charges when needed, so it won't overcharge. Make sure the charger suits your battery type, especially for AGM or lithium batteries, and plug it into a properly installed outlet.

Need an auto electrician in Mount Gambier?

Find local auto electricians and mobile services in the Mount Gambier directory, or start with your area: Mount Gambier.

Run an auto electrical business in Cold, Wet Winters and Flat Batteries on the Limestone Coast?

• New to Ozautoelectrics? Apply for trade pricing on quality auto electrical parts.
• Already a trade customer? Log in and order parts at your trade price.
• Want more local customers? List your business on this site so drivers in Cold, Wet Winters and Flat Batteries on the Limestone Coast can find you.

Not confident doing this yourself?

There’s no shame in handing it over. A local auto electrician can diagnose the fault properly and get it done safely, especially for anything involving brakes, airbags, hybrid systems or air-con gas.

Get a quote from a local auto electrician Or shop the parts and do it yourself