Most people don’t realize how much energy is wasted during braking. Moving vehicles generate a significant amount of kinetic energy. In traditional braking systems, friction is used to convert this kinetic energy into heat, thereby slowing the vehicle. Unfortunately, the heat dissipates, meaning a large portion of the energy produced is no longer usable. This is where the concept of regenerative braking comes in.

The car concept dates back to 1967 when the American Motor Car Company (AMC) developed a braking system capable of regenerating electrical energy. Today, many electric vehicles (EV) and hybrids (HEV) produced are equipped with this innovative braking technology. The system increases the vehicle’s efficiency by using the kinetic energy produced during braking to recharge the electric car’s battery. This energy recovery mechanism not only extends the car’s range but simultaneously reduces the mechanical wear of the brakes.

HOW DOES THE SYSTEM WORK?

In a conventional hydraulic braking system, friction components such as brake pads and discs do most of the work to slow the vehicle. When using regenerative brakes, however, the electric motor is the main component of the system. When the electric car’s brakes are activated or the driver lifts their foot off the accelerator pedal, the motor operates in reverse, causing it to turn backward and apply resistance to the wheels. In doing so, it acts as an electric generator, generating electricity that is then stored in the batteries.

For the majority of electric and hybrid vehicles, this energy recovery mechanism is used in combination with your standard hydraulic braking system. This means that when the regenerative braking system (RBS) does not provide enough torque to stop the vehicle, hydraulic torque is applied. A regenerative brake controller manages this switching process between the systems, while also helping to determine the duration and speed of brake application. Some systems allow for what is called “one-pedal driving,” meaning the RBS is capable of completely stopping the vehicle when the driver releases the accelerator pedal without using the brake pedal.

THE BENEFITS AND LIMITATIONS OF REGENERATIVE BRAKING

FREQUENTLY ASKED QUESTIONS (FAQ)

Electric cars are becoming increasingly common on roads worldwide. They offer several advantages over vehicles using internal combustion engines: they are significantly quieter, as they don’t require multiple explosions to provide torque; they are cleaner, as they don’t burn fuel and produce no exhaust released into the atmosphere; and they are incredibly efficient. Their main drawbacks have been the flaws in their technology, which are slowly being resolved, and the general lack of infrastructure to charge the batteries that serve as the EV equivalent of a gasoline tank. The ever-growing number of charging stations, along with ways to charge an electric car at home, are making this less and less of an obstacle to seamless electric vehicle driving.

WHAT IS A CHARGING STATION?

A more technical term for charging stations is “Electric Vehicle Supply Equipment” (EVSE). This can refer to any number of devices useful for recharging electric vehicles, whether in public or private. The European Automobile Manufacturers Association (ACEA) provides the following definitions for parts of EVSE: an outlet that supplies power, a plug that fits into that outlet, a cable made of insulated conductive material, a connector at the other end, and a vehicle inlet that accepts this connector and powers the electric car. We will focus on EVSE integrated into people’s private residences.

CHARGING AN ELECTRIC CAR AT HOME

Cars of any type spend a good portion of their time parked near their owners’ homes. Since this usually means they’re not going anywhere overnight, it would be the ideal time to recharge an electric vehicle or refuel its gasoline tank equivalent. And fortunately, the answer to whether you can charge an electric car at home is a resounding “yes”! There are two basic options to properly accomplish this feat:

Mains connection. Electric cars come with the necessary equipment to plug them into a standard outlet connected to the electrical grid. The advantage is the flexibility offered by being able to recharge the car almost anywhere. However, there is a huge drawback: charging a car this way is incredibly inefficient and can take more than a day under the worst circumstances. This method is best suited for emergencies or if the electric car is used infrequently.

Wallbox Chargers. These devices are integrated into the home electrical grid but have various features that enhance charging. Most are fast chargers that take much less time than the equipment provided with the car. Additionally, there are programmable variants that allow for customized charging times. This helps reduce the load on the electric car’s battery or enables charging during times of the day when electricity prices are lower, if applicable.

THE ADVANTAGES OF CHARGING A CAR AT HOME

The costs to properly charge an electric car in 2021 at public stations can vary significantly. Many charging stations cost £1.50 per hour, but faster chargers may require up to £3 for 45 minutes, not including an additional price per kWh consumed by the car.

Opting to install a home charging station can significantly reduce these costs, as now only the price of electricity determines the cost of charging an electric car (once the purchase and installation cost of the unit is deducted, of course).

HOW TO INSTALL AN EV CHARGER AT HOME

Consumers face the agony of choice when it comes to installing a home charging station for their electric car. Regardless of the system chosen, the home installation of an electric car charger should always be done by an expert with the necessary qualifications. There are dozens of options, but here are the different electric car chargers by type:

Fast or slow charging. Most wallboxes will provide AC electricity up to 7.4 kW. This is more than double that of a standard three-pin socket but only about a third of what faster 22 kW chargers can provide. DC and rapid charging devices are generally not available for home charging.

Smart charging. Additional features, such as programmable hours, help differentiate home charging stations from one another. Less complicated versions are cheaper but are at best less efficient and at worst risk long-term damage to the electric car’s systems.

The device can be installed almost anywhere on the premises of a private home but must naturally be near off-street parking. Wallbox providers typically handle the installation themselves, usually at no extra cost. The choice ultimately depends on how much one is willing to spend and the time it takes to charge the electric vehicle. Hybrids usually charge faster than fully electric vehicles.

THE BEST ELECTRIC CAR HOME CHARGER FOR YOU

This of course depends on your wants and needs as well as your electric vehicle’s specifications. As mentioned above, hybrids generally don’t require as much juice to operate as fully electric cars, meaning that lower-end devices may suit them perfectly for a full overnight charge. Check your car’s battery capacity and compare it to the different charging rates of the available wallbox types to determine how long it would take to fully recharge your vehicle. Also consider how often you drive your vehicle: the more you’re on the move, the more the battery capacity will be depleted, and the less time you’ll have to recharge the vehicle. A fast charger is more suitable in these cases. If you only drive rarely, a slower charger will suffice.

Although on average, electric vehicle (EV) batteries take about 8 hours to recharge from empty to full, the number can vary significantly, ranging from 30 minutes to 12 hours. This depends on the charging speed allowed by your electric vehicle, the power of your charger, and other factors.

There are a number of things you need to know about charging electric vehicles to properly and efficiently recharge your baby, whether at home or at a public charging station. Continue reading to discover the basics of electric vehicle charging and the most common reasons that could slow down your vehicle’s home charging speed.

AC Charging vs DC Charging: The Basics

Before starting, it is essential that you understand the two types of electrical power or “fuels” that electric cars consume, as they enable two types of charging with different charging speeds: alternating current (AC) and direct current (DC). While the energy from the grid is always alternating current, batteries like those in your smartphone or electric vehicle only store energy as direct current.

This means that your electric vehicle, as well as most electronic devices, have a built-in converter in the plug to convert the grid’s alternating current into direct current, which the batteries can store. With EV charging, the difference between AC charging and DC charging is whether the AC power is converted inside the car or outside.

AC Charging: AC charging is the standard and still the most common charging method for electric vehicles. All electric vehicles have a built-in converter inside, called an onboard charger, to convert alternating current to direct current and then feed it into the car’s battery. The conversion occurs inside the car with AC charging.

DC Charging: Unlike AC charging, the conversion of AC power from the grid to DC power occurs inside the DC charger, thanks to the converter built into the charger itself. This means there is no need for the car’s onboard converter, since the DC charger can convert AC power to DC and directly supply the car’s battery with DC current.

DC chargers available at public charging stations are an exciting breakthrough with a much faster charging speed. They are larger and enable a faster charging experience. This type of charger typically takes about 20 minutes to charge your battery to 50% and about 75 minutes to restore it to full charge.

Home EV Charging

You can charge your EV at home, at the office, or on the go while traveling using domestic outlets in your home or CEE outlets.

Domestic Outlets: All electric vehicles come with a charging cable that allows you to plug into any 120-volt domestic wall outlet you find inside your home. The charging cable and plug for charging with a standard wall outlet are often provided by the car manufacturer for emergency charging on the go. Domestic outlets can also sometimes be found at public charging stations.

With the appropriate fuse, you can plug your EV into a domestic outlet to achieve a charging speed of up to 3.7 kW (230 V, 16 A). This is called Level 1 charging. If you plug into a domestic outlet at an unknown location and therefore haven’t been able to check it beforehand, a maximum charging power of only 2.3 kW (230 V, 10 A) is highly recommended to avoid electrical problems.

CEE Outlets: The more advanced version of Level 1 home charging is a charging cable with a connector for different industrial CEE outlets for higher charging speeds. The CEE plug is available in single-phase and three-phase variants:

• A single-phase CEE plug is also called a camping plug and is blue in color, with a charging power of up to 3.7 kW (230 V, 16 A)
• A three-phase CEE plug is red in color and is intended for industrial outlets:
  • large industrial CEE 32 outlets with a maximum charging speed of 22 kW (400 V, 32 A)
  • small industrial CEE 16 outlets with a maximum charging speed of 11 kW (400 V, 26 A)

Level 2 Home Charging Station: For some electric vehicles, you can install a Level 2 charging station in your own garage for convenient home charging, but this will require professional installation and wiring. It is generally not a DIY project. Level 2 home chargers are often available for all-electric cars.

Level 2 charging stations offer a charging speed several times faster than Level 1 charging, at 240 volts AC. For any purely electric vehicle like the Nissan Leaf, having a home charging station is essential for overnight charging.

Slow Home Charging Speed: Reasons

If you find Level 1 charging too slow, opt for Level 2 for more efficient and faster charging. But note that when you recharge your EV at Level 2, the electrical flows between the grid and your vehicle can be hindered by some potential bottlenecks, as follows:

Mismatch Between the Charger’s Rated Current and the Electric Vehicle’s Maximum Charging Rate

The term “Level 2 residential charging stations” or “Level 2 chargers” may not have as much consistency as you think. Level 2 chargers for recharging your EV at home are typically rated in amperes, which specify the amount of current a given charger provides at 240 volts. And Level chargers can have varying amperages: 12, 16, 20, 24, 32, 40, 48, 64, or 80 amperes.

The maximum recharge rate of an electric vehicle is expressed in kilowatts. This metric concerns the vehicle’s onboard charger module, which converts alternating current to direct current. The more power the car can accept, the faster it can recharge.

To enable the most efficient and therefore fastest charging, your charger must match your electric vehicle’s charging rate. How can you tell when they are in different measurements? Simply multiply 240 volts by the amperes the charger is designed for and you get watts, which can be converted to kilowatts.

For example, if you have a Level 2 charger rated at 20 amperes, then 240 times 20 equals 4,800 watts or 4.8 kW. This is a good charger for the best-selling Nissan Leaf, which has a maximum charging rate of 3.3 kW. In short, the amount of current provided by a charger at 240 volts, when converted to kilowatts, must be greater than your electric vehicle’s maximum charging rate.

Nowadays, around 7.2 kW is more common for pure all-electric vehicles, and newer models even offer 10 kW and more, such as the Ford Mustang Mach-E with 10.5 kW and the Volkswagen ID.4 with 11 kW.

You Don’t Have a 240-Volt Circuit Capable of Harnessing Your Electric Vehicle’s Full Charging Capacity

For more efficient charging and shorter charging time, you need a dedicated circuit that can fully utilize the maximum charging capacity of your electric vehicle and your charger. Every 240-volt circuit has a current limit, which is determined by the diameter of its wires and the distance those wires have to run between the fuse box and the location where you charge your electric vehicle.

Longer cords have more resistance, which slows down the charging speed. To meet the current demand for Level 2 EV charging, you need sufficiently robust wiring, which in turn will require a larger conduit.

The circuit breaker should always provide about a 25% margin. For example, a Level 2 charger rated at 32 amperes will require a 40-ampere circuit breaker. A 40-ampere Level 2 charger will require a 50-ampere circuit breaker.

While there are countless benefits to driving an electric or hybrid car, a major concern for most prospective buyers is the cost of replacing EV batteries. The cost of Chevrolet Bolt EV batteries would be around $15,000. So, how long do electric car batteries last?

Although the typical cost of replacing electric vehicle batteries is not as high as for the Chevrolet, it still amounts to a few thousand dollars. While most EV batteries come with an eight-year warranty, you might worry that the lifespan of electric car batteries is not that long.

So, if you’re considering buying an electric or hybrid car, read on to find out how long electric car batteries last in order to factor the battery replacement cost into your decision.

How much does EV battery replacement cost?

Battery replacement is a must on the electric car maintenance checklist.

It is generally accepted that the cost of replacing EV batteries ranges between $1,000 and $6,000. This is a significant expense, but prices seem to be slightly decreasing over time in recent years.

EV Battery Basics

The batteries used for electric vehicles are lithium-ion batteries, the same type as those used for your mobile phones and laptops.

Compared to ordinary batteries, they are much lighter. They also have a much higher energy density, meaning they can extract a greater amount of energy from a small battery. They are also less likely to lose their charge when not in use.

The capacity of an EV battery is measured in kilowatt-hours or kWh. The higher the power rating of a battery pack, the longer you can drive before needing to recharge the battery. This capacity is also referred to as the battery’s “range.”

How long do electric car batteries last?

Many factors affect the lifespan of EV batteries. In general, you can expect most electric vehicle batteries on the market to last at least 8 years or about 100,000 miles. Most batteries of electric cars sold in the United States also come with a warranty of at least 8 years or 100,000 miles.

Another statistic for your peace of mind from Consumer Reports, an independent nonprofit research organization. It estimates that a typical EV battery would last about 200,000 miles, or nearly 17 years of use if driven 12,000 miles per year. That’s double the average warranty for most electric car batteries sold in the U.S.

You can look for electric cars with batteries that have a longer-than-average warranty. To name just a few, Kia offers a 10-year warranty for all its electric car batteries. Hyundai goes even further by offering lifetime coverage for its EV batteries.

10 years is longer than the warranties on any other component of a car. In fact, 10 years is longer than the period most car owners would keep a car.

Notes on EV Battery Warranty

When purchasing an electric vehicle, make sure to carefully check the warranty details.

Typically, many manufacturers offer warranties for EV batteries if, during the warranty period, the battery’s ability to hold a charge deteriorates to a certain level, which is usually 60% to 70%. Brands like Nissan, Volkswagen, BMW, Chevrolet, and some Tesla models and a few others offer this type of warranty.

However, be aware that some electric vehicle manufacturers may only offer a warranty if the battery completely loses its ability to hold a charge, meaning if its charging capacity deteriorates to 0%. This is extremely rare, so you would not prefer this type of strict warranty.

So, you might wonder, what would cause EV batteries to completely lose their charging capacity? Or what factors would affect the lifespan of EV batteries?

What affects the lifespan of electric car batteries?

Charging and Discharging

Over its lifespan, an EV battery will degrade slightly with each charge and discharge. However, such loss is gradual and minor, and the depletion rate tends to decrease over time.

The Battery’s Operating Range

That said, it’s worth noting that older batteries generally have a shorter operating range, meaning they would discharge more quickly and thus require more frequent charging. The more frequent the discharging and charging, the faster the battery will lose its charging capacity and the shorter its lifespan will be.

Where You Drive

For gasoline-engine vehicles, city driving with a lot of traffic, i.e., slower speed with many stops, consumes more fuel than driving on highways at a consistently high speed without frequent stops.

In contrast, electric vehicles tend to consume more energy when driven on highways at a constant high speed, while they consume less energy when driving in the city.

Hot Climate

All batteries will achieve a maximum lifespan if used consistently in environments at 20°C (68°F) or slightly below.

Extremely hot weather is not the ideal environment for EV batteries to “stay healthy.” In general, it is reported that electric cars driven in hotter climates tend to suffer from faster battery depletion and thus a shorter lifespan.

This is because heat damages the lithium-ion chemistry or the chemical reaction occurring inside the battery. To counter this issue, you may want to look for a liquid-cooled battery.

Ultimately, you can expect your EV batteries to last at least 8 years or 100,000 miles, or even longer if you take proper care of them.

Knowing how long electric car batteries last may not seem important to potential buyers at first glance. However, if you’re considering buying a durable electric car model that will last a long time and you plan to stick with it long-term, the lifespan of EV batteries will significantly affect the cost of owning an EV.

Have you ever thought about taking your Tesla to an automatic car wash to discover the car wash mode? However, do you know how to put Tesla in car wash mode and use it correctly? If so, you are in the right place, as there will be a lot to cover on this topic.

We will discover the Tesla car wash mode and how you can use it. Then we will go through the advantages and disadvantages of using this mode. We will also find out how much this service costs or whether you should wash your Tesla at home. So, if you want to learn more, stay tuned.

The Basics of Tesla Car Wash Mode

Before we dive into how to put Tesla in car wash mode, we will first discover the basics of this specified mode. Knowing this will help you understand and fully grasp its operation and purpose on a Tesla car.

So, what is the Tesla car wash mode? Well, it’s a special mode that has been installed on modern Teslas. This mode is specifically designed if you want to wash the electric car and go through an automatic car wash system.

It is essential to avoid damaging the car during a wash service. As during the wash time, the entire Tesla should be neutral, not operating in electric mode. Additionally, the Tesla car wash mode locks all doors, closes open windows, and disables certain features such as automatic wipers, sentry mode, and the parking sensor chime.

Imagine you have unfortunately forgotten to close one of the windows. The car will get wet if you are not careful. Or perhaps you forgot to activate the automatic wipers. In that case, the wipers could be severely damaged (impaired) and destroyed.

So, ultimately, always be cautious when using electrical items, big or small, because you won’t know how and when you might destroy them on a beautiful Sunday morning.

Which Tesla Models Support the Car Wash Mode Feature?

Ultimately, you are better off activating the wash mode whenever you use an automatic car wash type. However, did you know that not all Tesla models have this mode? Did your Tesla model even support this car wash function in the first place?

Standardly equipped in the newest Teslas like the Model 3 and Model Y, you can be assured that any new Tesla you buy today will include this mode.

On older models like the Model X and Model S, this feature comes with the newer lines, specifically the April 2021 updates. However, this function did not have an update on the early models of the X and S, as their old hardware may not be updated to support features like this.

Furthermore, you should check the menu and learn about the available updates. Because who knows, you might be eligible for this update on your Tesla vehicle. Just browse through the dashboard screen menu and see if the Tesla car wash mode is available.

How to Put Tesla in Car Wash Mode

Many owners, even if they have a Tesla, have never tried the car wash mode and do not know how to activate or use it in the first place. That said, we will now explain in detail how to properly put Tesla in car wash mode.

Overall, grasping the head-to-toe using the instructions in this mode is very simple. However, you can learn a proper method to speed up the process. Otherwise, you will be stuck with the flashing screen for more than half an hour trying to figure out how you can do it.

The steps are not too complicated because the process of setting up the Tesla Model Y car wash mode is the same as in Tesla Model X, Model S, and Model 3.

Step 1: Put Your Tesla in Park Mode

Before putting your car in Tesla car wash mode, you must first put the car in park (P) mode. Your vehicle should also not be actively charging.

Step 2: Select Car Wash Mode in the Touchscreen Control Panel

Go to the settings panel > select Service > look for and select Car Wash Mode.

Step 3: Select Enter Car Wash Mode in the Warning Window

After selecting the car wash mode, a warning window will appear. There, you need to select Enter Car Wash Mode.

Once activated, the Tesla Car Wash Mode prepares for a car wash by automatically closing, locking, disabling, and turning off various features.

• The windows, front trunk, and rear trunk will be closed to prevent water from entering inside.
• The charge port door will be locked to avoid damaging the port and charge door.
• The wipers will be disabled to prevent them from being activated and destroyed during the car wash.
• The parking sensor chime will be muted to avoid unnecessary beeping.
• Walk-away door locking and sentry mode will be disabled.

Step 4: Manually Manage Some Features If Necessary

The Car Wash Mode also provides the live status of all car wash-related features on the touchscreen. It displays a list of features, each with a status light and its state in text, serving as a checklist for car washes.

The status light will turn green if the necessary actions have been performed. It will turn red to alert when you need to manage a feature manually, as for a few Tesla lines, some existing modes are not equipped automatically.

For example, for the pre-2020 Tesla Model 3 car wash mode, if the trunk is not closed, its status light will turn red. The state in the menu will then be Trunk – Open. You can also manually control the climate system and other functions and set them to cyclic or off.

Step 5: Select the Foldable Mirrors

The Tesla Car Wash Mode also provides a Mirror Fold button. It is necessary to choose the type of foldable mirror so that the mirror is not affected by any force during the car wash.

How to Disable Tesla Car Wash Mode

There are two ways to disable the car wash mode on your Tesla:

• Press the “Exit Car Wash” button and your car will automatically exit the wash mode.
• Drive as you always do and the wash mode will be disabled when the speed exceeds 10 mph.

Is Tesla Car Wash Mode Useful?

Having a dedicated mode to perform all these changes in one batch by pressing a button every time you wash your Tesla saves a lot of time. Having a checklist right on your screen is also a reminder of what you need to do (or not do) when it’s time to wash your car.

You might say it’s a small thing, but if you own a Tesla and wash your car regularly, this feature will save you time and effort. There is nothing new with this feature since you can perform each of these changes yourself. But the difference lies in the number of clicks and the screens you need to access.

Using an Automatic Car Wash on Your Tesla

As you probably know, everything has its pros and cons. Car washing too. So, what are the advantages and disadvantages of using a car wash mode on an automatic car wash service?

Advantages of Using an Automatic Car Wash for Tesla

The biggest advantage of using an automatic car wash is convenience. This type of wash is easy to run. Everything is done by the machine. This means you have nothing to do that makes you sweat and tire you out. When your car is thoroughly washed, it dries completely by itself. Go in, then come out. As simple as that.

And frankly, it’s one of the best ideas that has come to life because, since its creation, it has saved billions of hours of manual labor. And that’s a lot of time, to be honest. Another advantage of using an automatic car wash is the low cost. If you already know, car washes are affordable. It won’t make a difference if you take your car to the car wash once or twice a month.

That’s why we recommend washing your Tesla automatically. But not everything is sunshine and roses. There might be something not optimal with this service, so you need to be cautious and well-prepared all the time.

Disadvantages of Using the Automatic Car Wash for Tesla

We have learned how to put Tesla in car wash mode and covered all the advantages of using automated services. But what are the disadvantages?

One of the biggest disadvantages of using an automated car wash is the problem of damaging your car. Another disadvantage is paint damage caused by the machine. The machine’s brush can create swirls in the car’s paint, and after a few washes, they can worsen.

Overall, the disadvantages do not outweigh the advantages. So you can take your car to the automatic wash, but make sure to activate the Tesla car wash mode. You’ll be ready to go.

How Much Does a Tesla Car Wash Cost?

We have discovered the Tesla car wash and how it works, and we think it’s time to learn more about the amount you can expect to pay at an automated car wash.

On average, an automatic Tesla wash costs about $10 to $20. It depends on where you take your car. But that doesn’t mean it’s worth it. In some places, prices are higher because there simply are no automatic car washes in the area. Some owners might be charged even $50 in some cases.

Although we recommend looking for reputable and reliable car wash locations in your area, you will find one that can do the job for cheap with high quality.

Remember that whenever you take your car, always activate the Tesla wash mode and ensure everything is closed or turned off properly. Additionally, being cautious with this function will ensure that your car’s sensors do not vibrate in danger when the car is in the automatic soap wash.

How to Wash Your Tesla Yourself

If you are sure about using a hand Tesla car wash at home, you can refer to the following steps to make the process easier.

• Step 1: Pre-wash the Tesla car with water to remove dirt from the body.
• Step 2: Use the 2-bucket method to clean Tesla from top to bottom. Fill one bucket with a car wash soap solution and the other bucket to collect dirty water and rinse your car wash gloves. First, dip your gloves in the soapy solution. Clean your car, then dip them in the second bucket to rinse or wring them out. Divide your car into different parts and clean them one by one so you don’t miss any spot.
• Step 3: Once you are satisfied with the results, the next process is to dry your car. We recommend using a microfiber towel to dry your car. Microfiber towels can absorb large amounts of water and are not abrasive. Once the drying process is complete, check the car once more to ensure you have covered all spots.

Waterless Car Wash Method

A waterless car wash, as the name suggests, uses no or very little water. All you need is a waterless car wash method and microfiber towels for a perfect car wash. Here’s how you can wash your car with the waterless car wash method:

• Divide your car into different parts.
• Spray the waterless car wash solution on the body and let it sit.
• After a while, wipe it off with a microfiber towel. While wiping, remember not to press too hard or go in circles. Wipe in one direction only.
• Use different microfiber towels for the car parts.

Touchless Car Wash Service

If you don’t have time to wash your car using the above methods, you can turn to a touchless car wash service. The instruction manual of some Teslas warns against going to an automatic car wash and only to a touchless car wash. In a touchless car wash, no device or tool comes into direct contact with your vehicle. Therefore, there is no possibility of causing scratches.

Conclusion

We have just gone through a few announcements on how to put Tesla in car wash mode. I hope you can gain a deeper insight into this issue and prepare yourself with basic knowledge so that all future projects go smoothly.

Having a weak battery when you’re in a hurry is frustrating, and worse, it could leave you stranded. Although there are many reasons why your battery may keep dying without warning, you can do certain things to get the juice back into your vehicle, depending on how “dead” your battery is.

It’s one of the basic skills of car maintenance to know when a dead battery is actually the cause of starting problems, how to check if your battery is dead and how dead it is, and whether you can recharge a completely dead car battery. In this article, you’ll learn the signs of a dead battery and how to revive it, as well as understand what happens inside a battery when it’s dead, when a battery can no longer be revived, and tips to avoid completely draining your precious battery.

When is a Battery “Dead”?

“A dead battery” can be a confusing description. Usually, it’s a battery that is depleted or discharged to such a low level that it won’t provide enough power to effectively start the engine, so you’ll have difficulty starting your car, or your car might not start at all.

However, there are different “levels” of battery “death.” A battery can be dead, but almost, which is when it’s depleted or discharged to a dangerous level but can be recharged again. A battery can die like this and be revived a number of times during its life, but after a certain point, it will truly die and can no longer be revived. The only option then is to replace your battery.

It’s important to know how dead your car’s battery is before deciding how to recharge it. For this, you’ll need a multimeter or a voltmeter, both are cheap and handy devices for diagnosing battery problems. A healthy battery will show 12.4 to 12.7 volts at both terminals.

If the voltmeter shows less than 12.4 volts, you’ll likely encounter problems when trying to start your vehicle. The lower amount will determine the method you need to use to charge the battery after starting your vehicle, and below a certain point, your battery will be truly “dead,” meaning it cannot be revived in any way and must be replaced.

If you experience one or more of the following symptoms, a dead battery is most likely the culprit. Some of these telltale signs can also be caused by other underlying issues elsewhere, so it’s important that you test your battery’s voltage with the appropriate tool after encountering these problems to check its condition.

The Engine Doesn’t Start

Your car relies on your battery to start and run the engine. So, when your car’s battery is dead, the most obvious sign is that the engine doesn’t start when you turn the ignition key. That said, there are many possible reasons for a hard starting problem. To narrow down the culprit, you’ll need to listen carefully when turning the key.

If you hear and feel nothing at all when turning the key, it means the starter isn’t getting power. The starter is responsible for turning the engine over when you turn the ignition to initiate the engine’s operation by its own power.

When in addition to this symptom, you also experience one or more of the issues below, it’s highly likely you’re dealing with a dead or depleted battery. Otherwise, there are other underlying causes, including a faulty ignition switch or a blown fuse.

The Engine Doesn’t Start but the Starter Cranks

Another possibility is that when you turn the ignition key, the engine doesn’t start but you hear the starter. The starter always makes a distinct sound when it engages with the engine via a flexible toothed plate or flywheel and physically turns it over. You should be quite familiar with the sound your car makes when you turn the key.

If one day it sounds different or you don’t hear it at all (as in the symptom above), there’s a problem with the starter itself or the battery or other parts. How the sound changes can help you identify the culprit.

If the starter cranks at a normal speed, then you have a fuel problem or a faulty spark. If the starter cranks several times then stops completely, or cranks very slowly and seems labored, you’re dealing with a dead battery or a faulty starter.

The most common cause is that the battery doesn’t have enough charge or voltage to operate the starter properly. So, the starter may be able to turn the engine over, but doesn’t provide enough power for the engine to start and run on its own. In some cases, a faulty starter may try to draw more amperage or current than the battery can supply.

To identify the culprit, you need to perform a battery test using a multimeter or voltmeter to check if the battery has sufficient voltage and if all battery terminals are tight and clean (without corrosion). If the battery is intact and not dead, you can suspect a faulty starter. You should use an ammeter to check that a faulty starter is indeed drawing too much amperage from the battery before proceeding with starter replacement.

The Car Needs a Jump Start in the Morning

If you can’t start your car one morning without a jump start, but have no problems later in the day, two things may have happened and the battery isn’t actually the underlying cause but only related. First, there’s a parasitic drain on the battery overnight that drained its juice. In this case, your battery may be revived or it may die completely and need to be replaced. In any case, you need to locate the source of the parasitic drain and try to avoid it.

There are a number of electrical accessories in your car, including the stereo system, interior lights, door lights, dashboard, and more. Most of these features typically don’t drain your car’s battery when the engine is off, but small electrical incidents can still occur and drain your battery’s charge overnight. Interior lights (including door lights) and bad fuses are the most problematic sources of potential parasitic leaks. To avoid such electrical incidents, you should make it a habit to turn off all lights and ensure all doors are completely closed and locked before leaving the car, including your trunk and glove box.

The second underlying cause is extreme cold. It’s quite common to encounter hard starting or a no-start problem on particularly cold mornings. Very cold weather can freeze a battery, short-circuit the plates and the battery will no longer charge, or decrease the battery’s ability to provide current on demand to the starter. Lead-acid and lithium-ion batteries are particularly weak in extremely cold weather.

While younger batteries under 3 years old have higher resistance to extreme cold, a battery loses strength with age. So, if you live in a place that frequently drops below freezing in winter and your battery died one morning, you’ll likely need to replace it very soon, even if you might be able to get a few more trips out of it after one of the methods we’ll discuss later. And you’ll want to get a new battery with a higher cold cranking amperage to better withstand extreme cold.

Some Electrical Accessories/Functions Don’t Work

If one day you notice that many electrical accessories or features aren’t working properly or not at all at the same time, it’s usually a red flag that the battery is dead and can’t provide power to operate these accessories.

For example, dashboard lights and headlights may be dimmer than usual or not come on at all, or if you insert your keys while the door is still open but don’t hear the familiar chime, or your dome light doesn’t come on.

Note that if something isn’t working but others still are, the battery probably isn’t dead. For example, if your door chime isn’t working, but other electrical accessories such as dashboard lights, headlights, and radio are working, the culprit is likely a faulty door switch or a blown fuse. Or if it’s only the headlights and radio that won’t turn on, the problem could be a blown main fuse or wiring issues.

What Really Happens Chemically in a Dead Battery?

As mentioned above, whether a depleted battery can be recharged or revived by other methods depends on how “dead” it is. This will decide the best way to revive the problematic battery, or if the battery is truly dead and therefore must be replaced.

Mishandling a depleted and deteriorated battery will only send it to the end of its lifespan much faster and can also put excessive strain on or damage other components of your car. Therefore, before moving on to discussing safe and appropriate ways to recharge or revive a completely dead battery in the next section, you must first understand what happens chemically inside a dead battery.

A car battery is made up of alternating plates of lead (Pb) and lead oxide (PbO2), and these plates are suspended in an electrolyte solution of water and sulfuric acid (H2SO4). When the battery discharges, the battery acid solution facilitates the flow of electrons from the lead plate to the lead oxide plate. This generates an electrical current, which is used to power the engine or operate other electrical accessories.

Due to this chemical reaction, sulfur is extracted from the battery acid and the lead plates of the discharged battery are now coated with lead sulfate (PbSO4). This “sulfation” process occurs virtually every time you discharge the battery and that’s where the potential problem lies.

If the battery is immediately recharged after being discharged, which usually happens, the reverse chemical reaction will occur immediately and reverse the previous sulfation process.

When the engine is running, the alternator charges the battery, or when you connect the battery to a dedicated battery charger, most of the lead sulfate coating on the lead plates returns to the battery acid. At the same time, hydrogen is also released. That’s why it’s possible to charge and discharge a lead-acid battery over and over again.

So, if the battery remains charged, the sulfation process is reversible, which is called “soft” sulfation. However, “hard” sulfation can occur if the car battery is left discharged for an extended period, which refers to the formation of lead sulfate crystals on the battery plates. These crystals gradually reduce the surface area of the plates available for the chemical reaction, thus decreasing the battery’s charge and discharge capacity.

Over time, this will worsen and lead to cracks and short circuits in the battery, and the battery will need to be removed for good.

In other words, while the sulfation process occurring on the battery plates is reversible, not all types of batteries can withstand only a limited number of charge and discharge cycles. Moreover, every time a battery is completely discharged, it suffers irreversible damage. So, a battery can only “die” completely and be recharged a limited number of times before it dies for real and needs to be replaced.

This means, therefore, that although in many cases, as mentioned above, the underlying cause of a hard starting problem is not a dead battery itself and so you just need to fix it and fully charge your battery to bring the battery back to life, a battery that has been jump-started or charged a number of times will need to be replaced anyway.

Can a Completely Dead Battery Be Recharged?

Unfortunately, it’s impossible to reverse hard sulfation. Still, if you have a dead car battery, you can try several things to get back on the road. That said, what you can do depends on the condition of the battery.

If the Battery is Almost Depleted

Driving: As we said, a healthy battery should have at least 12.4 volts of charge. Generally, if the battery still has barely enough charge, meaning if a multimeter test returns a reading between 12 volts and 12.4 volts, you can safely recharge it with your vehicle’s alternator. This means you only have to take your car for a drive to allow the alternator to charge the battery, but you must use as little electricity as possible to ensure nothing is unnecessarily consuming power and the alternator is sending as much power into the battery as possible. It’s best to go for a drive when it’s bright outside and turn off all lights and other electrical systems and accessories. The general consensus is that you should drive the car for at least 30 minutes to give the battery a significant charge and bring it back to a safe level for your next start.

If the Battery is Totally Depleted

A car battery is considered completely dead when the voltage drops below 12 volts. In this case, you cannot and should not try to charge the battery using your alternator as above, because the alternator was never designed to charge a completely dead battery.

Driving your vehicle to have the alternator restore such a completely dead battery means the alternator is forced to overwork to revive the dead battery as well as power other crucial components. This will damage the alternator, and moreover, the alternator cannot provide sufficient power to recharge a completely dead battery, so it only undercharges the battery. Undercharging will shorten the battery’s lifespan, while it won’t be able to effectively maintain the charge provided by the alternator.

Although using the alternator to recharge a completely dead battery is both inefficient and harmful to both parties, you can try the three methods below to safely extract juice from your dead battery:

Use a Dedicated Jump Starter/Battery Charger: The safest way to revive a seriously depleted battery is to connect it to a jump starter or a dedicated battery charger before or immediately after a jump start. Both are special charging devices designed to safely restore a dead battery to full charge. Most of the time, you won’t have to remove the battery to revive it.

Note: Do not turn off the engine, as the dead battery won’t accept a charge. Also, in the case where the battery is frozen, do not attempt to jump-start it because the battery case will swell and may explode. Thaw it first.

Distilled Water: If the battery’s acid or electrolyte level is low, a common trick is to add distilled water to fully submerge the plates again, which will allow a bit more space for the chemical reaction to occur. Adding distilled water may be enough to give the engine a few more turns.

Epsom Salt: This may seem surprising, but it’s basic chemistry. Epsom salt is something widely sold in grocery stores and commonly used to relieve muscle pain and constipation. It’s magnesium sulfate or MgSO4 and it’s a strong acid. When the battery’s acid level is low, you can add this strong acid with distilled water to the electrolyte mixture to tip the chemical balance, which might provide enough charge to give the engine a few more turns. Dissolve the Epsom salt with warm distilled water in a 1:3 ratio, then add to each cell until ¼” to ½” of the plates are submerged.

When a Dead Battery Can No Longer Be Revived

Even when you can get your car back on the road after a jump start or after recharging your dead battery with a dedicated charger, the buildup of hard sulfation is irreversible and will lead to the battery’s ultimate death, when its ability to hold a charge is zero.

Moreover, when a battery is left dead for an extended period, lead sulfate forms a buildup of hardened crystals that cannot be broken by the alternator, a jump starter, or a dedicated battery charger. The only option then is to completely replace the battery.

A battery meets its ultimate death when the multimeter or voltmeter returns a reading of about 10.5 volts or less. At this point, the lead plates are almost entirely coated with lead sulfate. There’s almost nothing left for chemical reactions to occur, so it may no longer be possible to restore the battery to full charge, or if it is possible, a full charge won’t last long, or the readings may show a full charge but in reality the battery can no longer reach its full charge.

Prevention is Key: Don’t Let Your Battery Die Completely

To avoid hard sulfation, hard starting problems, and premature battery replacement, you need to choose the right battery and take appropriate preventive measures.

Use a Float/Maintenance Charger When Your Car is Stored

As above, a dead battery must be recharged immediately, and leaving a dead or depleted battery for a long time will kill it completely prematurely. This means if you need to store your vehicle or leave it idle for an extended period, you’ll need to maintain the battery’s charge during that time.

To do this, you’ll need to purchase a float charger, also known as maintenance chargers, storage chargers, or trickle chargers. This type of charger prevents the battery from a natural process called self-discharge, where internal chemical reactions reduce the battery’s stored charge without any connection between the electrodes or any external circuit. A float charger will provide a charging rate equal to the battery’s self-discharge rate, thus keeping your battery at full charge.

Most maintenance chargers have built-in circuits to prevent overcharging so you can leave the charger on for the entire storage season. That said, some models don’t and can damage a battery by overcharging it, and no matter how high-tech your float charger is, you should still check periodically to ensure everything is still in good working order.

Without a healthy battery, your car isn’t going anywhere. Just like your complex body, your vehicle is a sophisticated universe of parts and mechanisms, and there are many reasons why your battery can discharge.

Although jumper cables can be a quick fix, a dead or unhealthy car battery is annoying and leads to inconvenient and costly repair or replacement. But it can also be avoided, with good maintenance and given that you know why your car battery keeps dying.

What happens if you have a weak battery?

The battery is an essential component. To maximize its lifespan and functionality and to ensure a hassle-free driving experience, you need to make sure your car battery is properly charged. When you have a weak battery, the charging system (i.e., the alternator) and the starter will draw excessive voltage to compensate for the battery’s lack of power, so they will be overworked and over time can malfunction.

Therefore, you should inspect and test your batteries as soon as there is the first sign of trouble, charging or replacing them in time. Otherwise, you might find yourself replacing expensive electrical parts, usually without warning.

Main reasons why your car battery keeps dying

Loose or corroded battery terminals

Your car battery can only function properly if the connections to the terminals are intact. All terminals must be free of contaminants and well tightened so that you cannot wiggle them by hand (you must be careful with side terminals, as you can strip the wires and penetrate the casing, causing an electrolyte leak).

Over time, battery cables and terminals are prone to corrosion. Additionally, the terminal connection can become loose. These will hinder the alternator’s ability to charge the battery and power the car, so you might have difficulty starting the vehicle. You could even stall while driving or damage the vehicle’s electronic components.

But don’t worry. Corrosion is an inevitable problem with all types of batteries. Corroded and loose terminals are not a serious problem and can be prevented through regular maintenance. Clean your car battery terminals with a commercial solution and a soft-bristled brush (remember to wear gloves and safety glasses), and a simple but effective trick to protect against corrosion is to add a little petroleum jelly to the terminals. Another simple solution is to apply liquid electrical tape to create a tight seal, but before removing the battery cable, you will need to cut it.

Your battery is just old and needs to be removed

Nothing lasts forever, including your car battery. Depending on how you drive and the climate of your place of residence, car batteries can typically last between three and five years. Once your battery reaches the three-year mark, it’s time to keep a close eye on it.

A number of factors can negatively influence your battery’s lifespan, including extreme temperatures and frequent short trips. If your car battery discharges quickly, even after a jump start, it’s a sign that your batteries are quite old and need to be replaced.

To track your battery’s health and know when it’s time to replace one, you will need a multimeter or a voltmeter, both of which measure the voltage stored in the battery at a given time. The energy to run the car is stored in the battery and is measured in voltage, and the voltage level in a battery is essentially its state of health.

A battery is fully charged when it contains 12.6 volts or more. When a battery drops to 12.2, it is only 50% charged and when it is below 12 volts, the battery is “dead” and must be replaced.

To use a multimeter to test a battery:

• Before using a multimeter to test a car battery, it is important to let the car sit for at least one hour or overnight. This is because the alternator produces electricity and charges the battery, and if the car has been running, the charge from the powered alternator will produce a misleadingly higher number on the multimeter.
• Locate the battery, which is often housed in the engine compartment under the hood, on one side of the engine. Set your multimeter to 20 DC volts by turning the dial to 20 on the “VDC” (Direct Current Voltage) range, which will allow you to accurately measure a battery storing between 0 and 20 volts (you must set the multimeter to a specific voltage range whenever you use it to test something). The multimeter should read 0.00.
• Connect the multimeter’s red (positive, marked “+”) test probe to the red (positive) battery terminal and the black (negative, marked “–”) test probe to the black (negative) battery terminal.

Tip – Knowing your battery’s age: Just like how your car tire deteriorates with age, even when stored safely, your batteries also lose their strength with age, even without much use and proper care. Therefore, when buying batteries, you should always buy a new one that was manufactured within the last 6 months.

To find out your battery’s age, you can check the four or five-digit date code on your battery case cover. You only need the first part of the code, which consists of a letter and a number, for example A20.

The letter is assigned to each month: A for January, B for February, and so on. The number that follows indicates the year: for example, 9 for 2009, 12 for 2012, 20 for 2020, etc. So, “A20” means the battery was shipped from the factory to local battery wholesalers in January 2020.

The alternator is not charging the battery properly

Your car depends on your battery to start and run the engine. But when your vehicle is running, your battery depends on the alternator to help it stay charged. The alternator produces electrical energy from the car’s mechanical energy and uses this electricity to charge the battery as well as to power various electrical accessories such as lights, radio, and air conditioner.

If the alternator does its job correctly, i.e., if it ensures optional charging of the battery, the battery’s lifespan will be maximized. But overcharging or undercharging will shorten the battery’s lifespan. Furthermore, if your alternator is not working properly, it is not charging your battery efficiently, so you might have trouble starting your car.

If the battery is in good condition and if the slow starting problem occurs when the car has been running, i.e., when the engine is warm, the alternator could be the culprit.

Like your battery, you should also test your alternator regularly or whenever you experience a hard starting or no-start problem. They must go hand in hand.

Note that you must always test the battery before you can test the alternator. This is because the battery starts the engine, and once the engine is running, it spins the alternator and this spinning keeps the battery charged. If the battery is too weak, the car won’t run and therefore the alternator cannot be tested. You need to perform two tests on the alternator to check if it is working correctly at idle without draining electrical accessories as well as at a higher speed under heavy use.

• To test an alternator’s no-load voltage: let the engine idle, turn off all electrical accessories that might consume electricity, including lights, dashboard, and stereo. Repeat the battery test above using the multimeter. A good alternator should produce a reading between 13.1 V and 14.6 V when the engine is idling normally. Anything outside this range means your alternator is undercharging or overcharging your battery, which will shorten the battery’s life.
• To test the alternator’s charging voltage to see if it will function correctly under heavy use: Have your assistant rev the engine to 2,000 RPM. Turn on all electrical accessories and reconnect the multimeter. A healthy, robust alternator should read 13.0 volts and above. Anything below 13.0 volts signals a weak alternator that needs to be checked by a professional.

A parasitic draw on the battery

While your engine is running, the alternator is powered and recharges the battery. However, when your car is off, the alternator cannot recharge the battery, while your battery still powers various accessories, including interior lights, clock, and radio.

Most of these usually don’t drain your car battery, but small electrical incidents can still occur and drain your battery. Interior lighting (including door lights) and faulty fuses can be potential sources of extra stress. To avoid such mishaps, often called parasitic drain on the battery, you should make it a habit to turn off all lights and ensure all doors are properly closed and locked before leaving the car, including your trunk and glove box.

Extreme weather conditions

Your vehicle’s battery is also sensitive to extreme temperatures, which is why drivers more often encounter hard starting problems on icy winter mornings and very hot summer days. “Young” batteries with fewer years on them can better withstand cold or intense heat, but older batteries are weaker with age and therefore have less resistance to extreme temperatures, and can even die completely.

According to AAA’s Automotive Research Center, a car’s battery is weakened by about 60% at 0°F and at 32°F, it loses 35% of its strength. Extreme temperatures can cause irreversible damage to your battery and what follows would be a costly replacement.

First, extreme heat can evaporate vital fluids from your battery, thus weakening its charge. It can also accelerate the corrosion process, which will damage the battery’s internal structure and shorten its lifespan.

Meanwhile, extreme cold can freeze a battery. This will cause the sides of the case to swell, short-circuit the plates, and the battery will no longer charge. Lead-acid batteries and lithium-ion batteries are particularly weak in extremely cold weather.

A battery has adequate resistance to cold temperatures when 100% charged, but as it wears out, this resistance weakens. At 50% charge, your battery can freeze overnight at -10°F. During the winter months, starting an engine will consume more current than is needed in normal weather, up to twice as much. This is why you are more likely to have a hard starting problem on icy winter mornings.

Since temperature has a significant impact on your car battery, you should choose a battery suitable for local weather conditions. It is best to consult your owner’s manual as well as a certified mechanic. Batteries specially designed to withstand extreme heat are often labeled “S” or “South,” while cold-weather batteries are often labeled “N” or “North.” In some cases, if you live in hot climates, you can replace your AGM battery with a traditional flooded battery to maximize its lifespan.

Frequent short trips with an old battery

You might know that the more constant-speed highway driving is better for your car in general, whereas a lot of stop-and-go driving in traffic jams would cause premature wear on many car parts. This is also true with your car batteries.

What happens when you frequently take short trips is that when starting the engine consumes a huge amount of power from your battery, the alternator may not have enough time to properly recharge your battery between drives. Over time, this significantly weakens the battery and shortens its lifespan, especially if your battery is already old.

Tips: how to ensure your battery’s good health

Choose the right type of battery for your vehicle

First, to ensure optimal performance and lifespan, you need to get the battery that fits your car. Each vehicle needs a different amount of power and a different size battery, so each vehicle requires a specific battery type. So, you should consult your owner’s manual to find out what type of battery is suitable for your car, or ask a mechanic what is best for your car.

For example, if you often take your vehicle off-road, you need a battery capable of withstanding constant vibrations on rough terrain. Many cars are equipped with AGM to support a growing range of electrical components, and the charging system can be configured specifically for an AGM battery. And in some cases, you can replace your AGM battery with a traditional flooded battery to increase longevity in hot climates (although the flooded type requires more maintenance as below).

Choose a battery with easier maintenance

Car batteries require regular maintenance to stay healthy. One way to save time and better ensure your battery is healthy even if you are not a DIYer is to buy a maintenance-free battery in the first place. If allowed, get a gel or AGM type battery. Thanks to advanced technology, these are sealed and do not require any special attention like flooded lead-acid batteries.

Flooded lead-acid batteries require more maintenance. They lose water during the charging cycle, so they must be topped up with distilled water only every 2 to 4 weeks, as needed, to function properly and stay healthy. Additionally, they must be equalized from time to time to ensure that each cell is equally charged. You can do this by applying a controlled overcharge once every 30 to 90 days.

Perform a load test regularly

While almost all car batteries today are supposed to be maintenance-free, regular inspection and maintenance are still crucial for any machine. It is recommended to test your battery with your alternator (no-load and load tests), preferably at least once a year as soon as it is 3 years old in a mild or cold climate, or once it is 2 years old if you live in a hot climate. This tests the battery’s ability to maintain voltage during use, and the results will tell you when it’s time to replace it.

Useful accessory: float/maintenance charger

All types of batteries are prone to a problem called natural discharge or self-discharge. This is an inevitable process, in which internal chemical reactions reduce the battery’s stored charge without any connection between the electrodes or any external circuit. Therefore, if you need to store your vehicle during the winter or in other circumstances where it will be inactive for a long period, you should invest in a float charger to maintain your battery’s full charge.

Also called maintenance chargers, storage chargers, or trickle chargers, these float chargers prevent excessive self-discharge when your battery is not used for an extended period. To prevent this, the charging rate of a maintenance charge is equal to the battery’s natural self-discharge rate.

Most maintenance chargers have built-in circuits to prevent overcharging so you can leave the charger on 24/7 without worrying about overcharging the battery, although some models do not and can damage a battery by overcharging it. Even though a float charger automatically monitors and charges the battery, it is still recommended to check periodically to ensure everything is still in good working order.

While you’re at it, it’s best to also get a portable battery starter and store it in your vehicle at all times as an emergency tool. These increasingly compact accessories allow you to easily start your vehicle without having to depend on another car.

The battery is an essential component that powers your car. Its health affects whether your vehicle can function properly or not at all. Therefore, to reduce your risk of breakdown, it is important to test a car battery with a multimeter regularly, at least twice a year. Don’t wait until the car starts showing signs of weakness.

If you’re having trouble starting your car or experiencing other telltale signs, there’s a good chance your battery is failing. Ensuring your battery is in good condition before a long trip can save you a lot of hassle. Testing the battery also helps you quickly determine if slow starting is the result of a failing battery or problems elsewhere. Here is a step-by-step guide on how to test a car battery with a multimeter, a cheap and handy tool for easy car maintenance at home.

How to Know When Your Car Battery is Faulty

The most common signs indicating that your car battery needs to be recharged or replaced:

• One of the most obvious signs is the battery warning light1. illuminated on the dashboard.
• The headlights are dim. When the battery is weak, it doesn’t have enough power to run your car’s electrical components.
• You hear a click, or nothing at all, when you turn the engine over.
• The engine cranks slowly when starting.
• You have to press the accelerator pedal to start.
• No-start: The car simply refuses to start.

What is a Multimeter?

A multimeter measures the voltage that your car battery is currently storing or the amount of energy stored in the battery. Sufficient power ensures your vehicle functions properly, while insufficient power requires immediate charging. It’s a simple tool for testing the condition of your car battery at home and in no time. It’s one of our recommended tips for maintaining your car at home, saving you time and money with mechanics. You can find a multimeter for as little as $8 on Amazon.

How to Test a Car Battery with a Multimeter – Step-by-Step Guide

A very convenient way to know if your battery is sufficiently charged is to use a multimeter. Follow these steps to use a multimeter to test a car battery:

1. Turn Off the Car for at Least One Hour

Due to how the battery discharges, it is important to let the car sit for at least one hour, or overnight, before using the multimeter to test your car battery. If the car is running when the battery is tested with a multimeter, the charge from the powered alternator, which is the component that produces electricity and charges the battery, will affect the “true” reading of the multimeter. If the car has recently been running, the battery is likely to produce a misleadingly higher number on the multimeter, so it is inaccurate.

2. Locate the Battery

The battery is often housed in the engine compartment under the hood, on one side of the engine. On some cars, the battery is located in the trunk for better weight distribution. The battery will often have a plastic cover that can be opened easily, or may require removing a few bolts or screws. After locating the battery, ensure no metal objects are touching the battery terminals. Keep all tools away.

3. Prepare the Multimeter

You need to set the multimeter to a specific range so it can measure within that range whenever you use it to test something. To test a car battery with a multimeter, set your multimeter to 20 DC volts, which will allow you to accurately measure a battery storing between 0 and 20 volts. To do this, turn the dial to 20 on the “DCV” (Direct Current Voltage) range. Sometimes this is indicated by the letter “V” with a solid line above a dashed line to its right. The multimeter should read 0.00.

4. Connect the Multimeter to the Battery

Touch the red probe (positive, marked “+”) of the multimeter to the red (positive) terminal of the battery. Touch the black probe (negative, marked “-“) of the meter to the black (negative) terminal of the battery.

5. Read the Multimeter.

When fully charged, batteries should have 12.6 volts or more. Note that when a battery drops to 12.2, it is only 50% charged. A reading below 12 indicates that the battery is junk and needs to be replaced.

6. Additional Test

Have an assistant start the engine and read the multimeter again. This time, if the revised voltage drops below 5 when the car is running, it must be discarded and replaced immediately. If the reading is below 10, it’s a sign that the battery is not in good enough condition to turn the engine’s starter.

7. Charge Your Car Battery if It’s Not Fully Charged

If you get a reading below 12.6, disconnect the battery by disconnecting the battery cables and unscrewing the hold-down mechanism that keeps the battery in place. Charge it, then test again after it has rested overnight. If the new reading is not higher, replace the battery.

Other Possible Issues with Your Battery

1. Damaged Battery Case and Cables

Damage to the battery case can also be the cause of a faulty battery. Have it replaced if it is damaged in any way. Check the battery cables for worn insulation, cracks, or fraying and have them replaced if necessary. If after inspection this is not the case, try checking the possible issues below.

2. Battery Terminals are Dirty or Corroded

Another common issue is corrosion or dirt buildup at the terminal connectors. You can get rid of corrosion or buildup using sandpaper, or a brush and cleaning solution (warm water and baking soda will work effectively). Remember to wear gloves and safety glasses to protect your eyes.

3. Alternator Test

The alternator produces electricity and charges the battery. If the alternator is working well, your car battery’s lifespan is maximized. If it overcharges or undercharges, the battery’s lifespan will be shortened.

Here’s how to test the alternator with a multimeter. Let the engine run and perform the same battery test as above with the multimeter. A good alternator should produce between 13.8 V and 14.4 V at normal idle. A reading outside this range means your car is undercharging or overcharging, both unhealthy for the battery and your vehicle.

We hope you find our guide on how to test a car battery with a multimeter useful for easy vehicle maintenance in your own home. Ensuring your car battery is properly charged is crucial to maximizing its lifespan and providing you with a pleasant, hassle-free driving experience with your vehicle.

If you are experiencing slow starting or no-start issues and the multimeter test shows the battery is in good condition, it might be your car’s starter.