Electrical
What is a Car Battery?
Stores the electricity that starts your car and powers it when off.
Simplified animation — not to scale.
In plain English
Most cars use a 12-volt lead-acid battery. It provides a big burst of power to crank the starter motor and keeps the lights, alarm, and clock running when the engine is off.
A simple analogy
"A big rechargeable AA battery for your car — only it weighs 15 kilos."
How it works
Chemical reactions between lead plates and acid create electrical energy. The alternator reverses the reaction while the engine runs, recharging it.
Signs of trouble
- ⚠Slow or no crank when starting
- ⚠Dashboard lights dim when turning the key
- ⚠Battery is more than 4–5 years old
- ⚠Swollen battery case
Rough UK cost
£90 – £220 fitted
Always get a written quote. Prices vary by car, region, and parts brand.
Heads up: Carautonomy is for general guidance only. If your car is showing warning lights or behaving oddly, get it looked at by a qualified mechanic.