Battery light is on

The battery light is on.
Experienced mechanics share their insights in answering this question :
Hi, this comes up often. Your car battery light being on is an indication that your engine is not getting enough energy. This could be because of a malfunctioning alternator or a battery going bad. I suggest having a certified mechanic, such as one from YourMechanic, come out and test your battery.

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The red battery light basically means that there is an issue with your alternator, your battery, or some other part of the charging system which could be as minor as cabling or as major as a computer malfunction.
There are several reasons why the car battery light might come on, but generally, the reasons are: An old car battery. Car battery connections that are corroded. Car battery cables that are misconnected.
An illuminated battery indicator can be caused by a number of issues, including: A loose or corroded battery cable. A problem with the alternator or voltage regulator. Damaged cells or plates inside the battery.
Can I Keep Driving My Car if the Battery Light Is On? Yes, you can, for a short time. The light indicates that the alternator isn`t charging the battery, which means your car`s electrical system isn`t getting the needed power.
The cause of the battery light could be a loose or corroded battery cable or other wire connecting components of the charging system, or it might be a problem with the alternator or voltage regulator. The alternator generates the power that is stored in the battery.
The alternator belt is the connection that interfaces the crankshaft and alternator together. If your car`s alternator belt isn`t working properly, your car battery won`t get the charge it needs for your vehicle`s electrical parts. With that, your car battery light will frequently be on to indicate such an issue.
I did a bit of research and found a battery reset is required to resolve the issue. The message can reset by itself, but the car needs to sit undisturbed for at least eight hours. Perhaps with your work/driving schedule the car doesn`t sit long enough.
This indicates that the alternator is not working properly. What is this? The most common cause of this problem is an alternator failure. Alternators are responsible for charging batteries in cars and other vehicles, and when they fail they can cause all sorts of problems with your vehicle`s electrical system.
Your battery needs to be charged if the battery light illuminates, signaling a low battery. You can reset the light by disconnecting the negative terminal of the battery for a short while if the battery or charging system of the automobile is working properly.
How long can I drive my car with the battery light on? If your battery light stays on while you drive, you`ll have roughly 30-60 minutes to drive with your battery lights on before your car may start stalling.
Red icons indicate a condition that requires immediate attention, such as an open door or low engine oil pressure.
“If the [battery`s] voltage is low, replace with a new battery or charge the battery to the recommended 14.2 to 14.7 volts,” he says. “Then try to run the vehicle and see if the voltage after is outside of that range. If it is, that`s a sign of a bad alternator.”
Make sure your alternator`s positive and negative terminals are clean. Put the multimeter`s black cable to the negative terminal and the red cable to the positive terminal. Look for an ideal alternator reading of around 12.6. Start the car, and look for a reading of between 14.2 and 14.7.
Alternator repair kits are usually less than $30, depending on which components you need to fix. Again, you need the proper tools and a little know-how, but if you`re able to find the right kit and know what you`re doing, you can rebuild an alternator for a fraction of the cost of even a remanufactured unit.
Alternators can go bad suddenly, or slowly over time. If your alternator is slowly going bad over time there are some warning signs you can look out for.
Most alternators will last between 80,000 and 150,000 miles — or about seven years. However, your driving habits and the area where you live could wear it out prematurely.
A dying, fading car battery means low voltage. As a result, your car`s computer, which is responsible for reporting error codes, is also receiving low voltage. An error code will be generated which will in turn trigger the Check Engine Light or even the Battery Charge Warning Light to display.
Manage battery usage:

Go to your phone settings > Apps. Find and tap Driversnote. Tap Battery. Select Unrestricted.

12.0 volts or below – At 12.0 volts your battery is considered to be fully discharged or `flat` and should be recharged as soon as possible. The lifespan of your battery will be severely affected if it remains within this voltage range for extended periods of time.
There is a secret code in the dialer, *#0228#, that resets the battery callibration completely, killing the phone straight to 0% and asking you to charge to full.
The check engine light is usually the most serious and feared warning because of the kind of damage it can signal. This warning often indicates the potential for serious engine damage. When ignored, your vehicle could suffer from a blown head gasket or a seized engine.
Master warning light: Appears as an exclamation point inside a triangle. A buzzer will sound, and the light will flash when the master warning system has sensed a malfunction within the Camry and is showing a message in the multi-information display.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

in my car battery warning light appearing while driving.so I have replaced both battery and alternater still light is on
ANSWER : As you may yourself have seen, there are many reports of this fault with the Civic, that is a battery or alternator is replaced only to have the warning light fail to extinguish despite checking every conceivable electrical possibility. Your only recourse is to have a certified mechanic go through that exercise with your car and that involves first attempting to "re-set" the light. If the warning light returns, the alternator output has to be carefully measured both loaded and unloaded. All terminal connections have to be verified including all grounds. Fuses have to be checked for integrity (continuity) and the possibility of shorts, in for example dash wiring, has to be checked. To request this repair, simply request an electrical components diagnostic and the responding certified mechanic will seek a resolution to this.

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The Battery Light is on and the lights and power mirrors are not working – 2002 Mercedes-Benz C320
ANSWER : Hi. If the Battery Light is on, this an indication that either the battery is bad, the alternator is not charging properly, or both of them are bad. Low battery voltage will cause the car to do abnormal things like have no headlights. There are other things that can cause headlights to not work as well, for example, a blown fuse, broken headlight relay, or, the most common cause, blown headlight bulbs.

I suggest you have a certified technician, such as one from YourMechanic, come to your location to determine why the Battery Light is on and suggest the necessary repairs.

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I have Chrysler 300c. Battery light came on, changed battery and alternator but power still getting drained and battery light still comes on.
ANSWER : Hi, thanks for writing in. This may be a sign of a failing starter relay. The starter relay is a small unit near the starter that directs power to the starter from the battery. When this fails, it may cause a clicking sound and will not allow the starter to engage the flywheel when you turn the key. I would suggest having a professional from YourMechanic come to your home to diagnose your starting issue to determine the solution to get you back on the road.

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Battery light goes on when I start car then turns off, if I rev engine light comes back until rpms go down. Abs goes comes on/off
ANSWER : Batteries can die due to faults in the charging system so ideally a suspected "faulty" battery should be load tested before a decision is made to condemn it. The only exception to this rule is if the battery is already clearly "old" (greater than 5 years) but even then once you put a new battery in, as a replacement for a "dead" battery, you have to comprehensively check out the charging system. Diagnostic Trouble Code P0460 will result in disruption of the dashboard fuel gauge’s ability to accurately report your tank’s fuel levels. The fuel gauge readings may be erratic, or read somewhere off scale. Vehicles equipped with a low fuel warning light feature may also suffer from erratic low fuel warnings in the event of a code P0460. Unless the P0460 code has been reported alongside other trouble code, all of the vehicle’s essential systems should otherwise function normally. I would recommend that you request a check engine light diagnostic to first resolve the fault causing the P0460 code to set. The check gas cap light warning light could be due a faulty gas cap and/or small leaks in the EVAP system.

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Battery light came on went and bought a new battery battery light comes on about 1 minute after starting car.
ANSWER : The alternator on this vehicle is computer controlled and if the alternator is not communicating to the computer then it may default to a set charging rate that will show up as good when testing using standard methods. The computer and charging system needs to be tested using a scanner that is compatible that can check and test charging rates. You most likely do have a bad alternator on the car.

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Car battery light is on replaced alternator battery and starter and battery light is still on.
ANSWER : You may have a failing voltage regulator that could be allowing the alternator to supply too much or too little amperage to the battery resulting in the battery never maintaining a consistent charge as it is designed to. The voltage regulator is a unit that regulates the charging of the battery by the alternator. When the voltage regulator is not working properly, this may result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. A common sign of this is usually the acid inside the battery boiling causing the battery to swell. You may also smell a bit of smoke due to things potentially getting too hot. In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. I would recommend having an expert from YourMechanic come to your location to diagnose your vehicle’s charging system.

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Abs light, emergency brake light, steering wheel assist light, engine light, EPC light, traction control light
ANSWER : Hello, thank you for writing in. The vehicle does utilize a lot of the same sensors for these systems. Are there any other codes that are coming up when this code appears? If so you will want to take these into consideration when processing the repair and making a diagnosis. The module may be bad, and replacing it should fix the problem. The lights should turn off once the main computer recognizes the new module and the sensors sync up. If you believe the sensors need to be cleaned you may do so. Do as minimal as possible to make sure you are not damaging the sensor or disrupting the wiring inside. A bad connection would make the lights stay on. With so many lights that are effected by the module being illuminated, the module is likely bad or does not have a connection. Check the connection first and then resort to replacing the unit. For more help with these electrical tests, contact our service department.

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No dash lights, back right tail light is out, no parking lights. Brake lights work though as does head lights.
ANSWER : Hi there. In many cases, when you have electrical problems like you’re describing, it’s caused by multiple electrical component failure. It’s likely that a few electrical relays are not working; especially if you have systems that utilize the same components (such as your brake light and tail lights). I would recommend having a professional mobile mechanic come to your location to complete an electrical problems inspection first, so they can pinpoint what is damaged and recommend the right repairs.

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