For others, its normal to see as low as 13 volts. You can tell if your alternator is overcharging by looking out for its indirect symptoms. Can You Jumpstart A Car With A Bad Alternator? He has owned his own business for seven years, and has for 10 years written on a variety of subjects from politics to the paranormal. 15 volts is generally considered a bit too high, but it really depends on what the manufacturer specified. When the electrolyte drops and can no longer cover the lead plates or lattices, your batterys capacity drops. Here are the common symptoms of alternator overcharging : Car Battery Overheating Battery Gauge Read High Car Battery Liquid Draining Battery Will Be Swollen Battery Electricity Will Be Low 1. Its not the most common symptom these days due to the extra monitoring of the charging system by the ECU, but on older vehicles, it can become a real problem if it is not addressed promptly. An overcharging alternator sends too many volts into the cars electrical system. Best of all, the system needs less tension and even a narrower belt can be used. As the electromagnetic field spins across the stator wiring, it induces a current in each of the three wire coils. What Causes an Alternator To Overcharge? - Rx Mechanic That indicator typically takes the shape of a battery logo. Alternator Overcharging the car battery symptoms. That can be anywhere from 15 to 19 volts. These new pulleys allow the alternator to free-wheel or overrun when the belt suddenly slows down. In that case, I would advise you to look up a vehicle-specific guide as it will show you the optimal way of accessing the alternator. Subaru Forester bad alternator symptoms, how to check voltage . An overcharging alternator can lead to headlights and tail lights prematurely blowing out alone or in tandem. A brand-new voltage regulator for virtually any car thats older than ten years costs between $20 and $50. (adsbygoogle = window.adsbygoogle || []).push({});
. This can cause the battery to be overcharged and/or codes to be set that may cause the charging light on the instrument cluster to illuminate. Fully charged car batteries usually give out approximately 12.6 volts when the engine is off. But itll most likely cost you much more. When checking the voltage output of the alternator you should try to get a reading at the alternator terminals instead of at the battery terminals. Its debatable whether a bad ground will cause the alternator to overcharge. Because of this, it wont function so effectively at producing current. Overcharging from a faulty regulator, dynamo or alternator New batteries that fail quickly, or existing ones that overheat, have physical damage, or have high voltage readings are also clear signs of the same problem. 6 Signs of a Bad Alternator - In The Garage with CarParts.com With these figures and a multimeter, we can easily confirm whether the alternator is overcharging your vehicle. In a way, it powers itself. A bad battery that doesnt hold charge will send a low voltage signal to the voltage regulator and thus increase the alternator output to abnormal levels, in other words, cause it to overcharge. As it reaches the end of its lifespan, the battery will lose its ability to hold an electrical charge. The battery may overheat and catch fire. But more worryingly, all that excess voltage is also going to all the cars electrical systems, which is a huge problem in modern cars with ECUs and multiple control modules. For example, the battery or alternator warning light will illuminate on your dashboard. Some cars even go through their entire life spans without any alternator problems. Not to mention, the car leaves you stranded at least once before that happens. It may have a tiny engine, but in eight years it's never once let him down! This might lead to a battery light on your dashboard, or, sometimes, you wont notice anything until you turn the car off. If your alternator is outputting more than 15 volts, it should be replaced or repaired immediately. The alternator overcharging means the alternator sends more voltage to the battery than it needs and more than its designed to handle. Since it is hard to keep an alternator spinning at a constant RPM as it relies on engine RPM, voltage regulators are used to ironing out any spikes in the system. Have your charging system checked and fixed as soon as you see the error codes or notice any of the overcharging signs and symptoms. The battery may leak acid or gas. In very simplistic terms, the alternator is responsible for charging the cars battery. As a rule, the key-off current drain on most late-model vehicles should be less than 50 milliamps (mA). However, loss of the electrolyte reduces the ability of the battery to discharge and recharge properly. Check out this step-by-step guide on how to test your car battery using a multimeter.. This is usually somewhere between 13 and 15 volts when the engine is running, but it can be higher or lower on some vehicles. In severe cases, the battery housing can become cracked or develop leaks, allowing the liquid electrolyte to leak out. 1. Symptoms of an overcharging alternator often include a battery warning light and/or check engine light coming on in the dash, blown-out fuses and bulbs, and an overheating battery. The problem is more likely to cause the alternator to undercharge, as the power is lost on its way to the battery. They will only notify you if a problem arises. In this video you will learn the common causes, why the battery is overheating and repairs to fix the issue. An overcharging alternator results in a voltage thats too high, so the battery light might not come on. If the ECU detects a problem with the alternator such as overcharging it will record this in memory and take the appropriate action necessary to protect the rest of the charging system and battery. If your alternator is overcharging, it means it's not regulating the voltage correctly and is sending too much power to the battery. The easiest method to check the alternator is by measuring the voltage at the battery terminals when the engine is running. Its charge sends the ions back into the solution. Create space around the alternator so you can work on it by removing components that get in the way. Bad Alternator Symptoms. Can You Jumpstart a Car With a Bad Alternator? The reading should be between 14.2 and 14.7 volts as the alternator starts recharging the battery. First of all, we should mention that a standard lead-acid car battery lasts between three and four years before it starts to show performance issues. The reading should still be higher than the base battery voltage, ideally above 14 volts. You can use an OBD2 scanner to diagnose and confirm that the alternator is causing a power issue. You will have to replace batteries more often. Platinum Spark Plugs & Their Differences, Service Shifter Light Lit on Jeep Cherokee: Meaning & How to Fix, Honda CR-V Years to Avoid (Best & Worst Years). However, if its been a couple of years since you last replaced the battery, its a good idea to test it before you do anything else. No reconditioning will fix it and you will need a replacement. The voltage regulator can be a mechanical device that physically breaks the circuit when the voltage exceeds a preset value. If the battery ground isnt good, the voltage signal will drop. Lighting that seems to swell in brightness with increased engine speed. Alternator Overcharging: What Causes It? - Let's Go For A Ride A smaller pulley will always keep the alternator rotating faster than expected. Imagine trying to diagnose a battery light that doesnt appear to have any reason to be on. However, it could also be damaged alternator wiring, corroded battery ground, or an old and damaged battery. Automatic transmissions with five or six speeds can drastically reduce engine speed when cruising. Its main job is to keep the car battery recharged, so its ready to deliver the necessary cranking power to start your vehicle the next time. Symptoms of Alternator Overcharging - Micdot The PCM would set a trouble code relating to that loss of communication. The ECU and the regulator are basically the same in modern cars. The voltage should be between 13.5 and 14.8 volts with the engine running. The voltage regulator gets a signal from the battery telling it how much voltage its picking up. You should never estimate when it comes to parking brake adjustments. Apply anti-seize on the bolt threads and slot them into the alternator holes. If it doesnt drop the current, it will cram more into the battery forcing its Voltage to go up hence the spike beyond the ideal 14.5V max. Meaning no matter how much you charge the battery, the voltage cant pass 12 or even 11. Overcharging a car lead acid battery will cause it to heat up and possibly swell. Hybrid Car Inverter Types, Function, & Common Issues. Therefore, it does not prove a faulty alternator. Luckily, we have already addressed that. Depending upon ambient temperature, charging voltage generally varies between 14.8 and 13.5 volts. That said, here is what causes alternator overcharging. An overcharged car battery can cause a number of symptoms, including: 1. Unfortunately, it can cause an overcharging, silent, but potentially damaging condition. My alternator is undercharging the battery - Car Talk Community It creates problems with fuses blowing and batteries struggling. Bulbs get more power with higher Voltage because while their resistivity is fixed, they have no way to clamp the voltage across them. When one component is worn, it impacts the other. Sulphation will be more rampant, and the battery will deteriorate quickly, forcing you to replace it. But in some cases, its cheaper to replace the entire alternator because the labor cost of replacing the voltage regulator outweighs the cost of a new alternator. Its only normal for those components to fail or blow after extended use. 3. When you buy with our links, we may earn a commission. However, it could also be damaged alternator wiring, corroded battery ground, or an old and damaged battery. If the alternator is to blame, install a high-quality replacement to keep your vehicle in excellent working condition. Still, some stores like NAPA will take your old battery and give you a discount on a new one, plus they will replace it for free in all circumstances. The most common alternator failure symptoms are listed below: Dim or especially bright headlights or other vehicle lighting. Variable and high voltage will significantly reduce the lifespan of light bulbs and cause premature burnouts. In that case, that means its being overcharged by the alternator. How To Tell If Alternator Is Overcharging? - Ask Car Mechanic The electromagnetic rotor receives charge from the battery as the car starts. Surprisingly, the alternator is capable of pumping out too much voltage, but normally only if something goes wrong. Here are the most common symptoms of a bad alternator in a GMC Envoy: A typical alternator Battery Light The battery light is designed to tell you that there is not enough voltage to properly charge the battery, or that the battery itself is not holding the proper voltage. Alternator overcharge is a serious problem, but with a good socket set and a replacement alternator, the problem can be fixed in under an hour. However, when you start the engine, that voltage will go up to as much as 14.8 volts. It could be $250 higher or lower. Aftermarket replacement alternators rarely have the exact specifications as the stock alternator. Other burnout symptoms of an overcharging alternator are repeated blown fuses, dash and interior lights blowing out and lights becoming extremely bright when engine speed increases. Over time, an overcharging alternator can damage the wiring looms in the charging system, causing them to become burnt or brittle. The actual charging voltage designed into a voltage regulator is dependent upon factors such as how far the alternator is located from the battery and the ambient air temperature surrounding the battery as calculated by the PCM. However, if the alternator is supplying enough power, but the battery remains under 12.6 volts, that means that the battery is dying. But on a positive note, thats with parts and labor included. However, if the wires are broken, its best to take the car to a professional to fix it because soldering is necessary. This puts too much pressure on the appliances. Beauty is more than skin deep. In rare occasions the service engine soon light may light up. Disconnect the negative terminal of the battery. Therefore, it does not prove a faulty alternator. Several battery testers have built-in features to test alternators. The ideal float voltage for a lead-acid battery is around 13.6V. In case your car has a battery voltage gauge, then thats your most apparent sign the alternator is overcharging because the reading will be too high. Scroll down to learn more about what causes an alternator to overcharge. Using a diagnostic tool such as an OBD II reader will give you access to stored error codes and some can allow you to record the voltage output of the alternator in real-time under varying conditions. All too often the alternator is condemned by technicians due to this test alone. What were the symptoms? Still, its worth checking the wires and paying attention to how long ago you got a new battery. We are an automotive mechanic blog that helps mechanics and car users to find the most recent and accurate technical and repair information for their cars. Even though modern vehicles have regulators to protect your electronics and battery from a rogue alternator, overcharging can still happen. Alternatively, you could remove the battery and look closely at it on a well-lit table. It then wont start the next time you come to it. Another symptom of an overcharging alternator is damage to the electrical system in the vehicle. Take your car to a mechanic or automotive electrician. New cooling systems anticipate and influence changes in coolant temperature. Vehicle Freak and it's operators shall not be liable under any circumstances in case of any injury, damage, or any other accident that may occur. If you see 14.7 volts on your multimeter, its a good idea to have the charging system and the battery inspected. Start your Forester. This affects the ability of the battery to charge efficiently and can eventually kill the battery completely. When your alternator is overcharging, its actively causing damage to the car battery. Through TheMotorGuy.com, he shares his knowledge and expertise with others, providing valuable insights and tips on how to keep your vehicle running smoothly. Some batteries could swell, crack, and leak their acid solutions. It might vary between 13.5 V and 14.5 V. These readings are perfectly acceptable and mean your alternator isnt overcharging. Does Lubrication Impact Bearing Functionality? How was it determined that the battery was being overcharged by quite a bit? And before you replace the voltage regulator, inspect all the alternator wiring and the batter ground strap for any damage, corrosion, or missing insulation. Another way to spot an overcharging alternator is by checking the condition of the battery. The most common symptom of an overcharging alternator is a high voltage reading when the alternator is running. If the battery is poorly vented, or is a fully sealed type, this buildup of hydrogen gas can cause the sides or top of the battery to swell outwards, warping the battery's casing. Getting a bigger battery with more reserve capacity can help you capitalize on this. This could also be caused by a number of other things, such as parasitic drains. The specific voltage that points to an overcharging alternator will vary from vehicle to vehicle. In this video you will learn the common causes, why the battery is overheating and. This error is triggered when the ECU detects a high voltage somewhere in the charging system. Of course, it could be a complex, in-depth problem. In other words, its an alternator controller. Simply speaking, the alternator is an electric generator that utilizes rotational power to generate electricity. At the other extreme, a battery that is sulfated due to being undercharged or not seeing constant use will maintain normal charging voltages. The alternator voltage output should be between 13.5 and 14.5 volts for a properly functioning charging system. Might. And thats the subject of this article. As a result, the output voltage whats going into the cars. They were a great way to tell the status of your electric system at a glance. These changes might be just 10 milliamps, so connections to the regulator are critical. If you'd like more information you can read our guide: https://vehiclefreak.com/what-causes-alternator-overcharging-and-how-do-you-fix-it/We recommend the following items:https://amzn.to/3EEafoJ - Klein Tools MM300 MultimeterWe cover the following questions and topics:alternator overchargingovercharging alternatorwhat causes an alternator to overchargewhy is my alternator overchargingalternator voltage too highcan an alternator overcharge a batteryhow to fix an overcharging alternatoralternator overcharging symptomswhat stops the alternator from overcharging the batteryalternator overcharging testcan a bad ground cause an alternator to overchargecan a bad battery cause an alternator to overchargeWe hope this video was helpful!DISCLAIMER: Any information we provide in this video is intended as education.
