As a car owner, you will (all too frequently) have to put your hand in your pocket and shell out considerable amounts of your hard earned cash to keep the thing running. Cars need routine servicing, parts wear out and things break.  All of these things can be expensive and inconvenient but having some basic parts knowledge could potentially reduce some of that cost and keep you on the road for longer.

A basic understanding of how some of the key components of your car work, what the signs of wear are and how they are maintained can be invaluable. As the saying goes –  Knowledge is power! In This article, we’re going to take a look at batteries, alternators and spark plugs.


The battery supplies power to all the electrical components in your car such as lights, radio and the car’s ‘brain’ – the ECU. It also delivers the power that ‘ignites’ your car’s engine The battery is recharged by the alternator.

A major weakness with modern lead-acid batteries is that they can’t handle being completely drained, for example, if the car’s lights are accidentally left on. When it’s fully drained, a battery’s electrodes get covered with sulfate deposits, which can kill its lifespan by a third or more. So make sure your lights are turned off before you walk away from your car and that any accessories such as dash cams are unplugged from the 12v socket

A car mechanic replaces a battery. Car Parts For Beginners

The price of batteries can vary a lot depending on the car and the brand of battery. Small, basic petrol engined cars tend to have pretty cheap batteries roughly €/£50-70 and larger diesel engined cars or cars with stop/start technology can use much more expensive batteries, well into the 100’s of €/£. Thankfully they’re extremely simple to change and it shouldn’t take much more than 10 minutes to do so the labor charge shouldn’t be too big.

How do I know if my battery needs to be replaced?

Is your engine slow to crank? You may notice that your engine is slow/sluggish to start taking longer than usual. This will be more noticeable in cold weather as batteries are affected by temperature

Is there a check engine light on your dash? Some cars show a warning light when the battery power is weak.

Is your battery fluid low? There is always an area on your battery that allows you to check if your fluid is at the correct level. If this fluid is low, than it is time to get your battery and charging system tested.

Does your battery look swollen or bloated? If your battery does look deformed it’s probably due to the battery overheating. This can be extremely dangerous and you should bring your car to a mechanic as soon as possible

Is your battery leaking? Battery acid is very corrosive and if it is leaking it can cause a build-up of gunk around your batteries poles.

How old is your battery? Batteries don’t last forever and will eventually need replacing.  As a rule of thumb, more expensive, branded batteries tend to last longer than the cheap and cheerful, non recognisable brands.

It’s looking a bit dated now but a few years ago we made this handy video showing you how to change you battery – Check it out!


Your alternator allows your car battery to charge while the engine is running. The alternator keeps modern car amenities running, including our cars’ powerful headlights, windshield wipers, heated rear windows, and more. This alternator is connected to many internal systems, so problems with other parts of the car can affect the alternator’s functioning.

Car Parts For Beginners

What are the warning signs that my alternator needs replacing?

Is there any warning light on your dash? Most modern cars have a dashboard warning light that alerts you when the alternator is on the fritz. Usually, the light will be shaped like a battery, though, some might say ALT (for alternator) or GEN (for generator). This light may only trigger if you are using multiple electrical components. It is generally contingent on how much life your vehicle’s alternator has left and how much electricity your vehicle is using.

battery-warning-light-large Car Parts For Beginners

Is your battery weak or dead? The alternator’s job is to keep your battery charged, however it can only do so much.  if your battery is goosed the alternator will not be able to bring it back to life. A dead battery won’t hold the charge that alternator is feeding it. A handy way of testing your alternator is to fully charge your battery and restart your car. If the battery is dead the car will still run but the lights will become dim. If the car struggles to start again your need to refer to your local mechanic to test your charging system further.

Is your alternator belt ok? The alternator in your car is belt driven. Is this belt is disconnected or slipping? If so the alternator cannot charge properly.

Are your lights becoming dim? If your alternator is failing you will notice a reduction in power in both your headlights and dash lights. This usually happens moments before you run out of power completely and the engine shuts off! So if you start to see your lights fade, get off the road quickly and get to a safe place.


Spark Plugs

The job of a spark plug is to create the spark required to ignite the fuel and air in a petrol engine, causing the combustion that makes the engineCar Parts For Beginners spark-plugs turn over. Spark plugs are often replaced as part of a ‘standard’ service on most petrol cars.  Long life spark plugs are becoming more common in new cars. Despite the initial cost of these plugs being quite high, you can save money in the long run by using them. Standard copper spark plugs tend to last between 10,000-20,000 miles where as long life plugs can last up to 60,000 miles saving you money on labor.

Click here to view spark plugs for your car

How do I know if I need to replace my spark plugs?

Is your car having problems starting? Often when people are having problems starting their car they put it down to a bad battery or a fuel problem, however, this could be a spark plug failing to supply the spark needed to ignite the engine – this would be extremely common.

Is your car idling roughly? Most cars idle smoothly at just under 1000RPM however if a spark plug is failing then it will cause a misfire resulting in the car running roughly and unevenly – it may seem like it wants to stall.

Are you lacking acceleration? If one of your spark plugs is failing then your engine will not fire on all cylinders, this will result in the engine being sluggish and will use more fuel.

Generally speaking, spark plugs are a simple DIY part that you can change yourself with only some basic tools. Check out our video to see how it’s done:

  • CarLover

    Its really excellent info.Thanks for very informative post you provided us which gave us a lot of information.

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  • Graeme Harding

    As a car owner, we should have some knowledge regarding car repair and maintenance. Apart from that, we may also aware about different car parts. So that whenever require we can easily deal with problems. For a beginner, this article provides some essential ingredients about car parts and car service. I would like to thanks for such a wonderful article with useful information for the beginners, it is definitely helpful for the vehicle owners.