Reasons Why Your Car Charger Port Is Not Working
If your 12-volt car charger port or cigarette lighter isn’t working, don’t panic! Here are some common causes and fixes for you to try.
Many drivers rely on the 12-volt car charging port to keep devices ready to go. So, what do you do when the car charging port or cigarette lighter is not working? After all, you don’t want to end up at your next destination with a dead phone.
In this guide, I look closer at all of the possible problems. I walk you through how to fix each complaint, so that the 12-volt power outlet works once again. I also take a minute to examine how wireless charging occurs in cars. At the end of the article, I will answer your top charging port questions.
Reasons Car Charging Port Not Working
The most common reasons why a car charger port is not working are due to contamination, the wrong cord, a blown fuse, a defective socket, or damaged wiring. Once you know what’s wrong, you can repair it and get your phone charging once again.
Here is some more detailed information on why your car charging port is not working:
Contamination
The first thing to look at is the cord and power outlet itself. If either of them has become dirty, it could be difficult to get the right connection for charging to occur.
Because the cord and port both sit in your car, dust and dirt can accumulate over time. Thankfully, this is one of the easiest problems to resolve. Plus, you can prevent this issue from occurring in the first place by regularly cleaning out the car to keep dust and dirt to a minimum.
Wrong Cord
To get your phone or tablet charging, you need to plug it into the port with a cord. You can use the cord that came with your device or you can purchase an aftermarket cord.
Either way, there are different types of data cords, so it’s possible you are using the wrong one. There’s also the chance that the cord has become damaged from wear. If you aren’t easy on the cord, the wires inside could have broken.
Blown Fuse
Everything electrical in the car runs through fuses. These fuses ensure that there’s never an overload that could cause a bigger problem.
Sometimes, the fuse can blow, rendering the electrical device unusable. When a fuse blows, other accessories may also stop working, depending on what that fuse is responsible for.
Defective Socket
The charging port is a socket that’s installed into the vehicle. Because it is a car part, it can fail at any time – especially if contamination has been allowed to infiltrate it.
If the charging port or cigarette lighter port fails, you won’t be able to charge your devices anymore. This can’t be determined until you’ve checked on the fuse first, because a blown fuse will also prevent power from getting to the port.
Damaged Wiring
Because both of these ports are electrical in nature, there will be wiring running to them. While these wires are designed to be durable and hold up under abuse, there’s still a chance that they can fail.
If the wiring gets caught on something, it could get bent or damaged. There’s also a chance that the wiring has ripped, especially if you have put the car in storage where rodents might have gotten to it. To determine what wiring needs to be looked at, you might want to search out a schematic in the service manual.
How to Fix a Car Charging Port That’s Not Working
Clean Connection
The easiest fix when a car charging port is not working – and the first place to start – is by looking at the connection itself. If you notice any dirt or debris, you can blow it off with compressed air and try again.
Your next step is to look in the charging port. With a small cotton swab, you can swipe out the inside of the port to clean it out. It’s best to avoid using any liquids, such as alcohol or water, in these ports.
Get a New Cord
Take your cord inside the house and try it with a port. If the phone charges inside, there’s nothing wrong with the cord. However, if it doesn’t work, you need to replace the cord. Research what type of cord is needed. There are different types, and you don’t want to purchase the wrong one.
Here are the four main types of cords that are used.
- USB-A to Lightning (older iPhone models)
- USB-A to Micro-USB (older Android models)
- USB-C to USB-C (newer Android models)
- Wireless charging car charger (A few Android models and iPhone 8-series or newer)
However, all four of these cords can be purchased individually online for around 5 to 10 each. Because it’s not much of an investment, it’s often wise to keep a few spare cords on hand for when one becomes damaged.
Replace The Fuse
The next step is to check the fuse. This is one of the easiest electrical problems to deal with. Find a diagram of the fuses for your car in the service or repair manual.
Once you’ve identified the fuse that runs these charging ports, you can carefully pull the fuse out and check it. If the filament inside the fuse is broken, it’s time to replace it. Make sure you replace the fuse with the same rated one as what was in there. This fix should only cost you a few dollars.
Replace Socket
If the problem isn’t your charging port or cord, and the fuse has been ruled out, you have to dive deeper into diagnostics. The socket itself could be defective, which would require a replacement. With a cigarette lighter, you can push in the end to see if the port works normally. Otherwise, you will need a test light to see if there’s power running to the outlet.
Don’t replace the port unless you have experience. The old port needs to be pulled out with pliers, and the new one can be inserted in its place. The cost for parts should be only 10 to 25. If you need further help from a mechanic, you might be charged for a half an hour to an hour of labor.
Repair Wiring
The worst-case scenario is that some of the wiring in the system has become damaged. Under normal usage, this won’t usually happen. It’s most frequently seen when cars are in storage and rodents can get into the systems. At the same time, there could be damage to other wires running to additional systems, leading to unrelated problems.
To find the damage, you will need to get an eye on all of the wiring to the ports. Once you find the wire that’s damaged, you need to replace it.
Best Car Battery Chargers
How We Tested
The car battery chargers in this article went through two rounds of reviews. We started by searching retailers like Amazon, RealTruck, and Advance Auto Parts for top products, looking at factors such as battery type, voltage, customer ratings, and prices.
Our product testing team then ordered the car battery chargers that best met these standards. A team member tested each product on a 2004 Subaru Forester, taking note of how quickly the car battery charger could charge a car battery, versatility, ease of use, and value. Each car battery charger was given a rating out of 5 stars based on these criteria.
Best Car Battery Chargers Testing Process
To test each car battery, we unpackaged it and attached it to a 12.0-V wet cell battery. We started the battery charger according to the instructions and measured the voltage using a multimeter.
During testing, our review team recorded careful notes about each feature of every battery. Evaluation across our review categories is based on our in-person experience and online customer reviews.
Charging Speed
By considering a battery charger’s voltage and amp hours, you can determine the approximate charging speed. Batteries that charge a car faster received a higher rating in this category.
Most car batteries are 12.0-volt. A higher voltage will charge a battery more quickly, but too many volts can damage your battery. A few volts above a battery’s rating are acceptable and even desirable, but a car battery charger must produce at least 12.0 volts to charge a 12.0-volt battery. Maintaining a consistent voltage is also important for charging speed and battery protection.
Versatility
Not all car battery chargers will work with every type of battery. While most cars use a wet cell battery, some may use an AGM, gel, or lithium-ion battery. Chargers compatible with the most types of batteries scored best in this category.
Additionally, some car battery chargers have features such as overcharge protection and trickle charging options. Such features also contribute to a battery’s versatility rating.
Ease Of Use
An easy-to-use automotive battery charger has long clamp cables and durable alligator clamps. Battery chargers are also easy to use if they have long outlet cords and straightforward interfaces and instructions.
Value
Our value score is based on the relationship between a battery’s rating in all other categories compared to the price.
Why You Can Trust Us
Each year, we test over 350 auto products on vehicles and in our testing lab. Our team of product testers thoroughly researches top products, unboxes and puts our hands on each component, and tests the items on real vehicles before making recommendations to readers.
We publish hundreds of product and service reviews to bring car enthusiasts detailed guides on automotive tools, detailing kits, car seats, pet products, and much more. For more information on our testing methodology and how we evaluate every product, check out our methodology page here.
Best Overall: Schumacher SC1280
The Schumacher SC1280 is a quick battery charger putting out 13.0 volts at a 15.0 amp current. It can fully charge a 105.0-Ah battery in 16 hours (this is relatively fast). The SC1280 is lightweight, portable, and easy to set up and use. It can automatically detect the battery voltage and adjust between 6.0-volt and 12.0-volt modes. While most cars use a 12.0-volt battery, 6.0-volt batteries are common in motorcycles. This charger includes a two-year warranty, trickle charging, and desulfation mode. It also has an automatic shutoff feature to help prevent overcharging. However, several reports say this automatic charging feature can malfunction.
Key Features
- Cost: About 50
- Battery type(s): Standard (wet cell), absorbed glass mat (AGM), and gel
- Amperage: 15.0 and 3.0 amp modes
- Voltage: 13.0 volts
- Weight: 3.0 pounds (lbs.)
- Warranty: 2 years
What’s In The Box?
There’s nothing included with the Schumacher SC1280 other than an instruction manual. The clamps are permanently attached to the device, which is designed such that the clamps are easily wrapped and stored.
Our Experience
The alligator clamps are a good size with long cables and therefore easy to use. The power cord is also fairly long, making it easy to set up to SC1280. The device’s computer automatically detects the proper voltage, so all you need to do is attach the SC1280 and press the start button to enter charging mode.
The voltage was tested at 13.0 amps while the battery charger was in use, which is in the ideal range for a 12.0-volt car battery. This voltage stayed consistent throughout. Perhaps our favorite feature is the LCD display, which can even provide an estimate of your vehicle’s battery charge.
What Customers Are Saying
Amazon Review Score : 4.6 out of 5 based on over 10,000 ratings
Many users are impressed with the charging speed of the SC1280 and appreciate that it can automatically detect battery voltage and adjust accordingly. Several reviewers note that this battery charger restored otherwise dead batteries after other chargers failed to do the same. Many say this is the best battery charger they’ve ever used with several others mentioning how helpful the LCD screen is.
The most concerning negative reviews are from customers who say the automatic shutoff feature failed to work. This can result in overcharging, which can permanently damage your car battery. While this doesn’t appear to be a common issue, it’s a concerning malfunction. Make sure the automatic shutoff works properly before leaving any charger on your battery unattended.
Most Rugged Design: NOCO Genius PRO50
Pros Includes 24-, 12-, and 6-volt charging modes High-quality components and clamps Very fast charging speeds
We recommend several NOCO battery chargers because all are built with reliable quality and backed by top-notch customer service. The Genius PRO50 is NOCO’s most powerful and versatile battery charger. In addition to offering many voltage and charging modes, this car battery charger features braided cable sleeves and the strongest alligator clamps of any battery charger that we’ve tested. Compatible with both gas- and diesel-powered vehicles, the Genius PRO50 is suitable for just about any battery you’d need to charge, even lithium-ion batteries. This charger is expensive and relatively heavy, so it’s not the best choice for those who only need a casual-use battery charger. For those with a fleet of batteries to maintain, the Genius PRO50 is a good item to keep in your garage.
Key Features
- Cost: About 740
- Battery type(s) : Standard, AGM, SLA, VRLA, and lithium-ion
- Amperage : 25.0 and 50.0 amp modes
- Voltage : 24.0-, 12.0-, and 6.0-volt modes
- Weight : 17.7 lbs.
- Warranty : 3 years
What’s In The Box?
The Genius PRO50 includes a solid EVA carrying case as well as several different power cords (for North America, European Union, United Kingdom, and Australia outlet types).
Our Experience
The first thing that stood out to us about the Genius PRO50 was the quality of the alligator cables. While many of our other recommendations (including other NOCO products) have well-made alligator clips, the Genius PRO50 has thick, braided cord sleeves that provide extra protection and longevity.
This car battery charger is a little heavier than a portable battery charger, but still smaller than stationary units like the Schumacher SC1309. We do note the lack of a display screen to provide battery data. While this isn’t a necessity for a battery charger, it’s a modern feature that would be nice to include on a unit this expensive.
What Customers Are Saying
Amazon Review Score : 4.4 out of 5 based on over 250 ratings
Most reviewers rave about the charging speed of the Genius PRO50 battery charger. Those looking to top up batteries for large engines like this charger. They claim it’s capable of bringing dead batteries back to life in fairly short order.
A few reviewers are upset that there is no display screen. There are indicators for the voltage, battery type, and charging mode, but no screen to show battery status. Another complaint some have is that some units arrive damaged because of poor packaging. However, NOCO does include a three-year warranty and customer reviews speak highly of the company’s customer service.
Trouble Free Ownership (Mostly)
Over the three years of ownership, we had a mostly trouble free experience. The Volt had to visit the shop four times: three were warranty/recall repairs and one was a self-induced tire repair.
The three warranty and recall repairs were covered 100% by Chevy. Only one repair required a couple of days, which prompted Chevy to give us a loaner while our Volt was being repaired.
Besides those repairs, maintenance has been incredibly minimal. I replaced the cabin air filter once, Chevy replaced the oil filter and did an oil change (covered by a free 24 month maintenance plan at purchase), and tire rotations every 7,500 miles (free at local tire shop).
All of this maintenance cost us a total of 14. Nice.
When looking at the maintenance schedule provided in the owner’s manual, the next 50,000 miles should bring similar low maintenance activity. Low maintenance is one of the many advantages of electric vehicles (EVs).
Gas Stations Become Irregular and Inconvenient
While the Volt is not an all-electric car like the Chevy Bolt (with a B) or Tesla Model 3, it does significantly reduce the need to visit a gas station. Because charging is done mainly at home and because the Volt has 53 miles of electric range, the need to fuel up is very infrequent. Really the only times we had to refuel was during out of town trips.
Other than that, the vast majority of the time we simply plugged in when my wife or I got home and woke up to a 100% charged battery. The battery has enough range to cover just about every regular trip.
During the events when we did need to refuel, finding and fueling at a gas station suddenly became a minor inconvenience. Gas stations are designed to be a dedicated stop where you refuel for 5-10 minutes and then hit the road again.
Charging an EV, however, is not a dedicated stop. While the charge time is longer than the refuel time, you are free to do other tasks such as visit the restroom or grab some food.
Because of this shift, my and wife I became used to not noticing how long our Volt took to charge since it was overnight. Only when we needed to refuel did we realize it was a bit of a detour on our trip.
Oh the Places You’ll Charge
Speaking of charging, and as previously mentioned, charging our Volt mainly took place at our house overnight. At first, we used a regular 120 volt outlet. This charged the Volt in about 12 hours and provided around 4 miles of range per hour.
When we first got the Volt, we were renters. We discussed this with our landlord and agreed to a small flat fee for the additional electricity usage since the landlord paid for electricity. This agreement prevented our landlord from increasing our rent more than a reasonable amount.
There are many other ways to charging an EV as a renter. Check out exactly how to go about this in this article.
A few years later, we purchased a home and got a 240 Volt outlet installed in our garage. To use a 240 Volt outlet with an EV, you’ll need a Level 2 charger. The charger that comes with the car is typically a Level 1 only charger (e.g. only 120 Volts).
The Level 2 charger charged our Volt in about 4 hours and provided around 10 miles of range per hour. Check out this article for Recommended Level 2 Chargers.
Every once in a while we would plug into a public charging station. To find these charging stations, we used the app Plugshare. Check out this article on How to Use Plugshare.
Many of these charging stations are actually free! The ones that did require payment cost the same or less than gas.
And again, while charging, we completed other tasks like shopping at the grocery store or hardware store.
Overall, charging at home (whether Level 1 or Level 2), cost around the third the cost than gas. Lower cost of operation is another advantage of electric cars.
Voltstats!
Voltstats is a website that provides, well, stats for Chevy Volts! By connecting your Volt to the website, you will be able to view daily and cumulative stats such as electric miles versus total miles, MPG versus MPGe, leaderboards, and more.
Per Voltstats, my Volt, has traveled 50,175 miles and 30,329 of which were electric. That equates to 60% electric. In other words, 60% of my miles were done by the battery, and the remaining 40% were by gas.
When looking at the leaderboards, there are a few Volts that have traversed more than 300,000 miles! Of those, around 100,000 miles of the miles were by the battery.
This was something that I was previously concerned about. I was unsure if the battery was capable of lasting over the years.
However, when I did my research, I found many Volts like these that have travelled many miles on their battery alone and even more overall.
The research
As the writer of this guide, I spent 28 hours researching and 85 hours testing EV chargers. I’ve been a science writer for more than nine years, covering a wide variety of topics, from particle physics to satellite remote sensing. Since joining Wirecutter, in 2017, I’ve reported on surge protectors, rechargeable batteries, power banks for phones and tablets, and more.
In preparation to write this guide, I interviewed Paul Vosper (CEO of JuiceBar, a manufacturer of commercial EV charging stations founded in 2009) about the history and current landscape of the EV charging industry. I discussed the ins and outs of installing an EV charger in a private home or an apartment building with Tracy Price (CEO of Qmerit, a network of certified electricians specializing in the installation of EV chargers) and Caradoc Ehrenhalt (CEO of EV Safe Charge, an EV charger installation and consulting firm). To better understand the needs and concerns of EV drivers, I interviewed Joe Flores, deputy director at San José Clean Energy, a nonprofit electricity provider; Suncheth Bhat, director of clean energy transportation for the Pacific Gas and Electric (PGE) utility company; and Aaron August, PGE’s vice president of utility partnerships and innovation.
Who this is for
If you’re in the process of buying an EV, and you want the fastest possible at-home charge right out of the gate, this is the guide for you. If you already own an EV, and you’re thinking about leveling up (literally) from a sluggish Level 1 charger to a speedier Level 2 charger, this guide is also for you. If you’re just here to learn, welcome! We hope you find what you’re looking for.
Gas-powered vehicles might still rule the road, but global EV sales doubled in 2021, and analysts expect there to be 26 million EVs worldwide by the end of 2022. We can safely assume that these millions of EV drivers, despite having at least one thing in common, have widely varying lifestyles, needs, and priorities: They could be homeowners in single-family houses or renters in multi-unit apartment buildings. Or they might be remote workers who rarely leave the house or ride-share drivers clocking hundreds of miles a day. Maybe they pass dozens of charging stations along their daily route, or perhaps they live 90 miles from the nearest public charger.
Regardless of your situation, though, having the most powerful EV charger possible at home will likely be a worthwhile investment. Per the U.S. Department of Transportation, a Level 1 charger can take days (40 to 50 hours) to charge an EV battery from empty to full, whereas a Level 2 charger can complete the same task in just four to 10 hours. Even if you don’t put many miles on your car, and topping off the battery overnight works for you most of the time, you still might want to have a charger at home that lets you juice up quickly in the event of a wildfire, flash flood, or other unforeseen disaster.
In addition to faster charging times, Level 2 chargers often come with features you might not get from the charger that came with your EV, such as:
- the option to hardwire the charger directly into your home’s electrical grid
- a long cord that can reach across a two-car garage or carport
- a smartphone app that supplements your EV’s app to track battery life, charge times, and more
- a weatherproof enclosure to add protection from elements
As is true of any home-improvement project, upgrading your EV charging setup will come at a cost. In addition to the sticker price of the charger, you’ll likely pay around 400 to 450,200 to have it professionally installed. You can circumvent some of these installation costs by buying a plug-in model, but if you don’t already have a 240 V outlet installed at your parking spot (they’re typically used for RVs or electric stovetops, among other things), you’ll still need to spend at least a few hundred dollars to take advantage of the Level 2 charger’s higher current. The silver lining here is that to help recoup the costs of going electric, many federal, state, and regional programs offer rebates and other incentives, including discounted rates for electricity usage during off-peak hours (which you can manage through your EV’s app or, if it has one, your EV charger’s app).
If you rent your home and you’re unsure whether your rental agreement allows you to install a Level 2 charger, check your state’s “right to charge” laws. Likewise, if you own a home or rental property, the U.S. Department of Energy has a trove of resources explaining the various rules, regulations, and rudiments of installing EV chargers.
How we picked
To find the most well-known and widely available makers of Level 2 EV chargers, we sniffed around the websites of major retailers like Amazon, Best Buy, and Walmart, as well as industry publications such as Car and Driver, CleanTechnica, Electrek, and InsideEVs. From there, we built a list of contenders based on the following features:
- Costs less than 5000,000: Most chargers we considered cost 450,000 or less, but we were open to pricier options that add an extra feature, such as the ability to charge two EVs at once. The annual savings from switching to electric will vary depending on your driving habits, the type of car you drive, fuel costs, and a variety of other factors. But whether you spend 500 or 5000,000, your EV is likely to pay for the cost of your charger in less than a year. In 2022, according to a AAA study, powering the average EV will cost 5000,100 less per year than fueling a traditional car, and that doesn’t even include the reduction in maintenancecosts. (You can see how your car stacks up using an online calculator from the U.S. Department of Energy.)
- Has at least a 32 A maximum current rating: To provide the fastest possible at-home charge, Level 2 chargers run off a 240 V circuit, passing between 16 to 80 A of current to your vehicle. Since most EVs come with a portable Level 1 charger capable of trickle charging up to 32 A from a standard 120 V outlet, we made that our minimum amperage requirement.
- Has at least a 20-foot cord: Longer cords tend to be thicker and more unwieldy than shorter ones, but a lengthy cord is critical for an EV charger to ensure that it can reach the car’s charging port. A typical two-car garage is 20 to 24 feet wide, so we struck any chargers with a cord shorter than 20 feet from our testing pool. We didn’t set an upper limit for cord length, though the National Electrical Code (NEC) set by the National Fire Protection Association (NFPA) caps it at 25 feet, and we didn’t see any that were longer than that.
- Weighs 50 pounds or less: Even though most Level 2 chargers are intended for stationary use, you may occasionally need to lift your charger into a car trunk (to bring it on a road trip, say) or move it on and off a wall mount. As such, we set a weight limit of 50 pounds, since heavier loads have an increased risk of injury.
- Has a NEMA 14-50 plug and/or can be hardwired: Hardwiring is generally preferable to a plug-in installation, since it creates a more seamless (and, therefore, more energy-efficient) connection between your home’s wiring and the charger. Hardwiring also offers better protection against the elements (vital if you’re planning to install your charger outside) and can deliver between 15 A to 60 A to your vehicle, whereas a NEMA 14-50 (plug-in) connection can handle only 15 A to 50 A. On the downside, in order to hardwire your charger, you’ll need to have it installed (ideally by a certified electrician) and, if you ever want to move it, have it uninstalled. Since everyone’s living situations and needs are different, we can’t say that one method or the other is better across the board; in the end, we preferred each model in our testing pool to have at least one of these installation options, and we gave bonus points to those that offered both. We considered additional plug configurations (such as the less-versatile NEMA 6-50 plug, which lacks a neutral wire and is most commonly used for welding equipment) to be nonessential bonuses.
- Certified by a Nationally Recognized Testing Laboratory (NRTL): A seal of approval from Underwriters Laboratories (UL), Intertek’s Electrical Testing Labs (ETL), or any of the other testing facilities recognized by the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) indicates that a product meets rigorous safety and compliance standards. We required that each charger have a certification from one or more of these organizations.
- Has at least a one-year warranty: We think a year is ample time to use your charger on a regular basis and ensure that it’s not a dud. Still, a longer warranty period is nice, since it gives you more wiggle room in case a part breaks or your charger conks out unexpectedly.
- Can be used safely outdoors: If you typically park in a carport or other outdoor parking space, you’ll want to make sure your charger is protected from blowing dust, rain, and other inclement conditions. Even if you plan to keep your charger in an enclosed garage, it’ll still be exposed to the elements to a lesser extent when the door is open. We gave preference to chargers with more robust Ingress Protection (IP) or National Electrical Manufacturers Association (NEMA) ratings (two common grading scales for weatherproofing) and to those rated to withstand more extreme temperatures, so you can juice up in a variety of environments.
- Has a cord organizer: We preferred that each model in our testing pool include some type of cord organization system, whether it be a simple wall-mounted hook or an elaborate retraction system. Not only does this keep your garage looking tidy, but it prevents someone from tripping over the cord or running it over and damaging it.
- Has a history of positive : We ran some of our top contenders through FindOurView, a program that analyzes online user ratings and reviews to highlight common patterns. Although some models had an insufficient number of reviews for the software to analyze, this allowed us to identify a few models with consistently reported problems, which we then cut from our list.
An Easy Solution To Your Battery Charging Problems
A bad battery might be obvious, but determining the root cause of battery failure can be difficult. Your best bet is to get your entire electrical system inspected to be safe.
In this case, find a good automotive technician to deal with your charging issues.
- ASE-certified.
- Use only high-quality replacement parts and tools.
- Offer a service warranty.
And you’re in luck because RepairSmith ticks all those boxes!
RepairSmith is a convenient mobile vehicle repair and maintenance solution.
Here’s why you’ll want to consider them first for your repairs:
- Replacements and fixes can be made right in your driveway
- Online booking is convenient and easy
- Professional, ASE-certified technicians perform the vehicle inspection and servicing
- Competitive and upfront pricing
- Repairs are conducted using high-quality equipment, tools, and replacement parts
- RepairSmith provides a 12-month, 12,000-mile warranty for all repairs
For an accurate estimate of starting and charging repair costs, just fill out this form.
Now that you know what causes charging issues and how to fix them, let’s go over some FAQs.
Car Battery-Related FAQs
Here are the answers to some battery-related questions you may have.
What Happens When The Car Battery Won’t Charge?
If your car battery won’t charge, your car won’t start.
There isn’t enough power supply for the spark plugs and ignition system to engage.
How Does The Car Charge The Battery?
The standard car battery is a 12-volt battery (12V battery) with six cells.
Each battery cell holds 2.1 volts at full charge.
When you turn the key in the ignition, the battery routes the voltage to the starter motor, and the engine starts. The battery also provides the initial spark to the spark plugs in a petrol engine or powers the glow plug heater in a diesel engine (in subzero temperatures).
Once the engine is running, it drives the alternator via the alternator belt, converting mechanical power to electrical power, thus charging the battery.
How Can I Check For A Flat Battery?
If your car won’t start and the headlights are off, turn them on to check for a dead car battery.
Here’s how to tell:
If the headlights provide full brightness, the issue isn’t the battery, it’s likely a bad starter or faulty wiring in the electrical system.
If the headlights don’t turn on or are dimmer than usual, you might have a bad battery.
How Does A Mechanic Check The Battery Charge?
Your mechanic can use a basic voltmeter to check the battery voltage.
- They’ll ensure that the engine is off and set the voltmeter to DC (Direct Current).
- Then, they’ll attach the voltmeter to each battery post (the red lead to the positive terminal and the black lead to the negative terminal).
The reading for a fully charged battery should ideally be 12.6V /- 0.2V.
If it’s at 12.4V, it’s still considered a healthy charge but isn’t functioning optimally.
If it’s 12.39V or less, the battery isn’t fully charged.
If it’s over 12.9V, your battery likely has excessive voltage.
The voltmeter only provides the battery’s ‘state of charge’ — which indicates the level of charge a battery has relative to its capacity. At over 12.4V, a car battery capacity is at 60% or more.
For a more comprehensive view of battery health, they may use a battery tester that has a load tester to monitor battery voltage and current output.
Should I Replace A Battery That Can’t Hold A Proper Charge?
Yes, you should have it replaced with a new battery.
If the battery can’t charge up properly, it’s bound to fail at some point.
It’s better to be proactive and replace it now than to end up with a dead car battery when you least expect it.
How Does A Mechanic Check If The Alternator Is Working?
Your mechanic will use a voltmeter and the process is similar to checking the battery charge. However, this time, the engine will be running.
Your mechanic will connect the voltmeter to the battery. The voltage reading should be 14-15V for most cars. If it’s less, it means the alternator isn’t generating enough power for adequate battery charging.
If The Alternator Is Faulty, Will A Jump Start Work?
Yes, if you have a faulty alternator, a jump start will work (whether from a jump starter or a donor car).
Just make sure the jumper cables are connected correctly.
However, if your alternator is faulty, your battery won’t last long, and your car will eventually stall. You might be able to drive a short distance if all unnecessary electrical systems are off.
That’s why it’s just better to get a mechanic to come over and handle your alternator and battery issues.
What Is A Battery Maintainer?
The battery maintainer (or battery tender) maintains the charge in a good battery. It can act as a float charger to bring voltage levels back to optimal if they drop.
It’s typically left connected to a stationary vehicle that is seldom driven, or used to deliver sufficient battery power for a car parked overnight.
However, it’s important to note that it can’t recharge a dead battery.
Is A Deep Cycle Battery The Same As A Car Battery?
No, these batteries are different.
While they’re both of the lead-acid variety, a car battery is designed to provide a short, high current burst of power to start a car’s engine. Only a small charge is used, which is later replenished by the alternator.
The deep cycle battery is designed to deliver sustained power with a lower current draw over extended periods. It’s typically used in boats and is also called a marine battery.
Final Thoughts
There are a lot of reasons why your car battery won’t charge, and determining the exact cause is your best bet at finding a solution that works.
That’s why, the next time you have battery issues, save yourself the hassle of troubleshooting things yourself. Contact RepairSmith, and ASE-certified technicians will be at your doorstep in no time, ready to do the figuring out for you!
RepairSmith RepairSmith is the easiest way to repair your car. Our ASE-certified technicians deliver quality car repair and maintenance directly to your driveway. We offer upfront pricing, online booking, and a 12-month, 12,000-mile warranty.