It's dark, it's cold, and the car just clicks or turns over slowly and dies. Cold mornings are when weak batteries finally show up. Here's what to check, in order, before you spend money.

If the car is parked somewhere unsafe, or you are stuck at the side of a busy road, read car broken down in Glasgow: what to do first. Safety comes before any of this.

Why the cold makes it worse

A car battery works by a chemical reaction, and that reaction slows down when it's cold. At the same time, cold engine oil is thicker, so the starter motor has to work harder to turn the engine. A battery that was just about coping in September can give up on the first frosty morning in November.

Short trips make it worse. A couple of miles with lights, heater and wipers on may not put back the charge used to start the car, so the battery slowly runs down.

Listen to what the car does

What happens when you turn the key or press the start button tells you a lot.

  • Nothing at all, no lights on the dashboard. The battery may be completely flat, or a battery terminal may be loose or corroded.
  • A fast clicking sound. Often a weak battery. There's enough power to work the starter's switch, but not enough to turn the engine.
  • The engine turns over slowly, then stops. Usually a tired battery struggling in the cold.
  • The engine turns over at normal speed but won't fire. The battery is probably fine. The problem is more likely fuel, ignition or a sensor, and that needs a mechanic.
  • The dashboard lights come on but the key won't turn. The steering lock may be on. Turn the steering wheel gently from side to side while you turn the key.

Simple checks you can do on the drive

You don't need tools for these.

1. Turn everything off. Headlights, heater fan, heated screen, radio. Give the battery its best chance. 2. Check the fuel. A gauge just above empty can mislead you. 3. Look at the battery terminals, if you can see them easily. White or green crusty build-up, or a loose clamp, can stop power getting through. Don't poke around a battery with metal tools. 4. Automatic? Check it's in P. Many automatics won't start in drive. Try N if P doesn't work. 5. Keyless car? Try the backup method. If the key fob battery is weak, the car may not detect it. Your handbook will show where to hold the fob, often against the start button. 6. Don't keep cranking. Trying again and again for a long time drains a weak battery further and can overheat the starter. Try a few short attempts with a pause in between, then stop.

Jump starting: when it makes sense

If the signs point to a flat or weak battery, a jump start from another car or a jump pack often gets you going. Follow the steps in your car's handbook, because the connection points differ between models and some cars have a specific place for the earth lead. Make sure the leads are in good condition and the clamps don't touch each other.

Once it starts, it isn't fixed. If you can, take a longer drive afterwards so the alternator can put charge back. If it won't start again the next morning, the battery is probably worn out, or something is draining it overnight.

The Highway Code (opens in a new tab) suggests carrying jump leads in winter, along with a scraper, de-icer, torch, warm clothes and a first aid kit.

When to stop and get help

Some things are not worth trying to fix yourself:

  • A smell of fuel or burning.
  • The battery looks swollen, cracked or is leaking.
  • The engine turns over fine but won't fire after a few tries.
  • Warning lights stay on once the engine is running, especially the red battery light. The Highway Code says that if the charge light comes on while you're driving, the battery may not be charging and should be checked as soon as possible.

If you have breakdown cover, call them. Some people have cover through their insurance or bank account without knowing it.

Battery or something else?

Many tyre and parts shops and garages can test a battery and the charging system. Our garage directory lists repair garages around Glasgow from public data. They're not our partners and we don't rate them, so check before you book. Ask for a price for the battery fitted, as some modern cars need the new battery registered with the car's computer.

If the car is old and this is one more problem on a long list, our guide on whether your car is worth fixing may help. Before paying for big work, look up the car's past MOT results on the free MOT history check.

Where we can help

Still stuck? Tell us what the car is doing. A real person reads it, and we can point you towards sensible next steps: a battery, a mobile mechanic, a local garage to ask, or whether it's time to think about another car. It's free to ask and there's no obligation. We're not a recovery company, so in an emergency call 999 or your breakdown cover first.