Battery light is on

took to tire shop and they put on a load test – suggested battery failed and alternator…replace both – still get the error msg. connections are tight on battery and belt seems to be tight
Experienced mechanics share their insights in answering this question :
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.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

What`s happening when the battery/check charging system light comes on? Whenever this light goes on, it means that the vehicle is running solely on battery power. If the problem continues and your charging system fails, the battery won`t be able to recharge and it will soon run down, leaving you with a dead battery.
The service battery charging system in your Chevy includes the alternator, battery, wiring, and the electronic control unit (ECU). It is what keeps your battery charged and produces the energy necessary to run your lights, radio, and other essential electrical components when your engine is running.
The Battery Saver Active message can appear on your driver information center (DIC). When the DIC displays this alert, that means that your battery has a low charge, and your vehicle is shutting off certain systems that may drain the battery of life.
Your battery light, also called the dashboard battery indicator, is designed to let you know about an issue with your vehicle`s battery or charging system. It could indicate that your battery is damaged or worn out, or that the charging system is malfunctioning in some way.
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.
Can I drive my car if it says service battery charging system? Keep Your Service Battery System Light Off When Driving. Your car could break down at any time if it needs a new battery, has a broken alternator, or has wiring problems.
An effective method to determine whether it`s your battery or alternator that`s gone bad is to connect jumper cables from a running vehicle`s battery to yours. After a few moments, try starting your vehicle. Once it`s started, remove the jumper cables — if your engine stalls, your alternator has probably gone bad.
You should turn the Battery Saver on when you`re low on battery and can`t charge your device, or even when you are about to go on a lengthy trip, and you know that charging your device will be problematic.
No. There`s no risk to your phone`s battery when you use Battery Saver mode. In some ways, it may even extend the battery`s life as you aren`t constantly recharging it. Ultimately though, you don`t have to worry about it ruining the battery while using this battery-saving mode.
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.
If your car`s battery is low, it may not be able to keep up with the demands of your vehicle`s engine. This can lead to a brief surge in power which causes the battery light to turn on, only for it to go out again as soon as you have enough power from your alternator.
How long your car can survive with the battery light on depends on a lot of factors, including the age and condition of your battery and the type of car you drive. In general, it will take around 30 to 60 minutes after the battery light turns on for the car to stall.
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.
How much driving to keep the battery charged? Experts recommend driving a car for at least 10 kilometres (and up to 30 minutes) at least once every week. If you find your car battery keeps dying when not in use, it`s a clear sign that you need a new battery.
While you can technically still drive with a bad alternator, it is not advised. This is especially true in newer vehicle models. This is because there is more electricity involved compared to an older model.
If your alternator fails when you`re far from home, you can typically drive up to 200 miles on battery power alone. That`s assuming your battery is in good shape and fully charged. Of course, it`s best to get the alternator repaired or replaced as soon as you can.
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.
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.
Another common reason that your iPhone stops charging is because of the temperature. As mentioned, heat is one of the quickest ways to damage and decrease your iPhone`s lifespan. If you`re charging your iPhone in a particularly warm location, the iPhone will automatically stop the battery from charging past 80%.
When it gets to a battery health level of 80% or less, then you need a new battery. the battery capacity does not need to be 100%. Look for a battery replacement when it gets down to 80%. If you insist on 100% capacity [Settings > Battery > Battery Health], you may be changing your battery every few months.
If your battery is discharged too low to attempt this, there are battery chargers available that are designed to recover severely discharged batteries. These devices work by sending pulses to the battery terminals in order to reverse sulfation.
Most car batteries will last between 500 and 1,000 charging cycles, which works out to a lifespan of between three and five years, depending on driving and weather conditions.
When the battery current sensor fails, the vehicle will not charge correctly, leading to a DTC or a dead battery. Common signs of failure include: Irregular charging rates. Low battery voltage.

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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