how your car battery works and signs it needs replacing

2018-04-15 22:18:56
maintenance

When you drive your car, you don't think about how it works. You just drive, expecting that everything will continue to operate as it should. However, car problems do transpire. Turn the key and wait... nothing happens. No cranking, not a click, not even a light flickering. Your battery is stone dead.

It's one of the most common car problems you can have. It's so common that many motorists carry jumper cables in the boot for just that situation. In some cases, lights were left on or the key was left on too long. Other times, the battery is toast and needs to be replaced.

Do you know when your car battery has given up the ghost? Here are signs your battery needs replacing.

How Your Car Battery Works

First, there's a quick chemistry lesson to learn. Your car battery is fairly simple in design, and understanding its composition might just help you know how to deal with a dead battery.

A car's electrical system is known as a 12-volt system. Your engine won't start with much less than that. So, a car battery is built to store 12 volts. It's separated into 6 cells that make 2.1 volts each. In each cell, there are two plates - a lead plate and a lead dioxide plate. Then, the works is submerged in a sulphuric acid solution, and a chemical reaction takes place.

But there's no electricity yet. The ions react with the lead plate, which produces hydrogen and lead sulphate. In all the split-second fury, electrons are released from their chemical bonds inside the battery.

Charged electrons race around inside the battery, which is how electricity is formed. All that electric energy is pent up until your car demands electricity to one of its systems.

Another important note: your car's electrical system will not operate if one of the battery cables is disconnected. Both the positive and negative leads must be in place for your car battery to do any good whatsoever. It forms a complete circuit - a loop, if you will - between the power and ground.

With that understanding, let's explore signs that your car battery needs to be changed.

Your Motor Turns Over Slowly

In the early stages of battery failure, your car might seem to be running right as rain. The only catch is when you attempt to start your car, it turns over extremely slow. You might feel alarmed at times, wondering if you're going to need to get the jumper cables from the boot. But just as you're about to, the engine fires up.

This is typically an old age issue with car batteries. What can happen after years of use is sulphation inside the battery. When a battery isn't charged fully, sulphate crystals can form on the negative plates inside the battery. It reduces the battery's capacity to recharge and the result is less electrical power delivered to the car.

Sometimes, a good battery charger can desulphate the battery. But in most situations, it's easiest and best to replace the car battery altogether.

Lights Flicker While the Motor is Running

A common sign that a battery is near the end of its useful life is when you start seeing electrical system failing during use. Headlights are the most common to notice as their usually bright light can be seen flickering against the night backdrop. You can notice it among other lighting systems like dash lights or interior lamps also, or with power windows that roll up slowly.

When you notice your car lights flickering, there are a few things to check. It could be a loose ground cable on the battery, or corrosion buildup on the battery terminals. That can explain the weak power being delivered. Your generator (or alternator) may not be producing the necessary output to recharge the battery.

But more often than not, it's a sign that there's an internal issue in the battery.

Your Battery Needs a Boost Often

You might need a boost because you've left your headlights on or listened to the radio with the engine turned off for too long. But it shouldn't be a daily occurrence.

Do you keep your jumper cables on the passenger seat because you use them so often? You're not alone. Batteries typically have an average lifespan of three to five years. If you're stretching that time frame, you could get quite comfortable jumping your battery.

Between sulphates, diminishing fluid levels inside the battery, and thousands of hours of use, batteries will eventually get too weak to hold a full charge. If you're boosting your battery as part of your morning routine, get it changed out.

The Battery Case is Bulged or Leaking

A car battery is heavy, but it's not as sturdy as you might be led to believe. In fact, in cold weather, it's actually somewhat delicate. In freezing temperatures, your car battery must have a full charge to keep its electrons moving and preventing the sulphuric acid from freezing. It must also be secured well in the battery cradle to prevent movement that could damage the case.

If the battery has frozen and the sides of the case are bulged out, it's doomed. The battery will need to be changed out because the fluid has frozen inside at some point. You can be assured that the plates inside have been damaged. And if there is ever fluid leaking from the battery, it needs to be replaced. The fluid is acidic, so don't get it on your skin, clothes, car paint - don't get it on anything, really.

Check Engine Light is On

Sometimes, you'll get an early warning from your car that the battery is on its last leg. Your Check Engine light may come on for dozens of reasons, one of which is low voltage. The common diagnostic trouble code, or DTC, for low voltage is P0562.

Low voltage can be attributed to the charging system, but it can also be due to a failing battery. If the Check Engine light illuminates and the DTC is P0562, there's a fair chance your battery needs to be changed.