Battery Discharge Warning Meaning Causes and Fixes Guide

Battery discharge warning meaning causes and fixes are essential information all vehicle owners should know. A battery that loses energy and isn’t adequately recharged won’t power the car’s systems.

Battery Discharge Warning

Our car team has provided an extensive guide on the common causes and solutions of battery discharge warnings, so continue reading!

What Are the Causes of Battery Discharge Warning?

The causes of battery discharge warnings include parasitic drainage, switched-on headlights, switched-on radio, broken voltage regulator, plugged-in chargers, and defective batteries. Other factors that lead to discharge warnings for batteries include a broken alternator belt, short ground, and a faulty charging circuit.

A battery is discharging if it is losing its voltage. The discharge occurs when the battery’s energy is depleting, yet it isn’t replenished at the same rate. It is usual for a battery to lose its power, but the lost energy should be replenished by charging. Here are the various reasons why it might be failing to do that.

– Occurrence of Parasitic Battery Discharge

Battery discharge or drainage happens when a car’s battery continues to be in use even after the vehicle has been switched off. The usage can lead to the depletion of a battery while the vehicle is off to the point where it cannot charge back up when the engine is running.

An example of this drainage is when a faulty sensor light continues to draw power from the battery when the alternator is not recharging the battery. This drainage reduces the performance of the battery, and the discharge warning light will come on. If the drainage continues unchecked, it will reduce the battery’s lifespan.

So how do you prevent this from happening? You can prevent your battery from experiencing parasitic drainage by ensuring that you switch off the headlights and all other lights, radio, and electrical accessories before exiting the vehicle. Also, ensure you unplug all charging cables and keep the glove box and trunk properly closed.

– Headlights Were Not Turned Off

For most modern cars, it’s hard to leave the headlights on because of all the alert chimes and automatic systems. These systems will remind you that you are yet to switch off the headlights. However, it is not impossible to leave the headlights on after exiting the vehicle or the car is off.

Common Causes of Battery Discharge Warning

If your car’s headlights are on, it will use up much of its battery. This is because the car battery supplies the energy that powers the headlamps. A switched-on headlight will drain your battery when the engine isn’t running and can cause the battery warning light to come on.

– Switched On Radio

Like the headlights, the radio operates using the power from the car battery. Thus, if you exit your car and forget to switch off the radio, it will continue to use up energy from your Kia battery, and this will cause battery drainage.

Although listening to the radio while sitting in the parking lot or the garage of your home might make waiting for someone more enjoyable, it will affect your battery. When this happens continuously, it will lead to Kia battery discharge.

– Plugged In Chargers

Modern car models come with many conveniences, such as charging ports. Every modern car has one or more charging ports to charge your smartphone and its accessories. The smartphone is charged using the power from the car battery.

Now, it is expected that when you stop charging the device, the battery’s energy will stop depleting. However, this is not always the case. Sometimes, even after removing the phone but the charger is still plugged in, the battery will continue to be used. A battery will experience discharge if its power is being drained and there is no alternator working to recharge it.

– Defective Terminal Connections

The terminal connections have a critical role to play in the health of your battery. If you have corroded battery terminals, it can cause your battery to drain quickly. Also, having loose connections in your battery’s terminals can cause the battery’s power to drain faster, even though the battery is not being used. Thus, the battery light will come on on your dashboard.

– Faulty Alternator

The average car alternator is expected to last about 50,000 miles before it wears out. When the alternator exceeds this period, it can cause problems with the battery. The alternator is part of the system to charge the vehicle’s battery to power other car systems. Thus, if you have a bad alternator, it will be unable to perform its function, and the battery will drain.

– Defective Battery

After being used for some time, car batteries can become weak or damaged. When this happens, the battery will be unable to charge faster than it is being drained of power by the car’s systems. Any battery that doesn’t maintain the charge when the alternator and other parts are working correctly is already defective or has become a dead battery. Thus, a bad battery will keep discharging until it can no longer power the vehicle’s systems.

Likewise, corrosion in the battery’s terminals can make the battery defective. This type of battery will likely experience a discharge of the battery’s power. The accumulation of rust and other deposits on the terminals will prevent the battery from charging correctly. In the long run, this will cause the battery’s power to drain.

– Bad Grounding

Every vehicle battery is equipped with ground connections to prevent fires in the battery. However, they can also cause problems for the battery.
If there is a wrong or poor ground connection, the charge might flow toward the connection instead of charging up the car’s battery. The failure of the battery to charge while its power is being used up will lead to discharge and the warning lights will come on.

– Broken Serpentine Belt

All cars have a serpentine (or alternator) belt that rotates and supplies the alternator with the energy required to perform its function. If the alternator belt is broken, the alternator will not receive the energy needed to operate correctly.

This will affect the battery because it will not charge as it should when the vehicle is running and its power is being used. A stuck or slipping alternator belt also has the same effect on the alternator.

– Defective Charging Circuit

The charging circuit is part of the charging system for the battery so that it can carry out its functions. So if the charging circuit is damaged, it will not charge battery quicker than it’s drained of power, and this will cause a discharge.

Also, defective sensors and problems with the starter motor can prevent the battery from being charged properly. Thus, its power will be drained quickly.

– Adverse Weather Conditions

The average battery is designed to withstand varying weather conditions. However, once a battery becomes weak, it will no longer put up resistance against adverse weather conditions. Extreme weather conditions such as freezing cold and scorching heat can cause the battery to drain quicker than its being charged.

– Defective Connections or Short Ground

If the connections of the electrical system are not correctly done, it can lead to energy loss in the battery. Rusty, loose, or broken electrical connections can cause short ground. When this happens, it will affect the battery’s power, causing it to drain.

– Damaged Voltage Regulator

In most vehicles, the output from the alternator is inconsistent and varies considerably with the engine’s RPM. To solve this problem, a voltage regulator was introduced into the car. The regulator is used to manage the output power and keep it consistent. If the regulator is damaged or faulty, it will not properly charge the battery, and this will give room for drainage.

How Can You Fix Battery Discharge Warning?

You can fix battery discharge warning by starting the engine, jumpstarting the engine, inspecting the alternator belt, replacing the battery, performing battery maintenance, and testing the battery and alternator. Other ways to fix this problem include inspecting the electrolyte, inspecting the coolant level, and switching on the heater.

– Kickstart the Car Engine

When faced with a discharge problem, the easiest step to take is to kickstart the engine. By just cranking the engine, you could remedy the problem. Once you start the engine and the alternator begins to run, the battery will start charging. If the engine refuses to start, then you should try other remedies.

Revving the engine can charge your battery more quickly. Revving the car engine will make the crankshaft turn more rapidly, and this causes the alternator belt to spin more quickly. The quicker the belt rotates, the faster the battery charges.

– Jumpstart the Vehicle

A battery discharge can cause your vehicle to break down somewhere in the middle of the road or prevent you from leaving the house with the car. To remedy this unpleasant situation, you can try jumpstarting the vehicle.

Resolving Battery Discharge Warning Issues

Ask a fellow motorist on the highway or your next-door neighbor to help you jumpstart the car. If the jumpstart successfully starts the car, you should run the car engine for at least 30 minutes. Doing this will give the alternator enough time to charge the battery.

– Inspect the Alternator Belt

Since the alternator belt plays a significant role in battery charging, you should inspect it. Open the vehicle’s hood, locate the belt, and check for any sign of looseness, wear, or damage. If it is damaged or loose, the battery will not charge adequately. Thus, you should seek the help of an auto mechanic to repair the belt or replace it with a new one.

– Inspect the Battery Electrolyte

Batteries come with electrolytes. The electrolyte creates the chemical reaction that produces the electrical current used by the battery. Thus, if you have low electrolyte levels, it can cause power drain problems for the battery.

Inspect the electrolyte levels by checking the battery vents. If you notice that the battery cell plates are not submerged, it means there are not enough electrolytes in the battery.

– Change the Battery

Sometimes, when it comes to damaged or old batteries, you can do nothing to remedy the situation. If you try jumpstarting the vehicle and it doesn’t work despite having sufficient electrolyte levels, the next option is to replace battery.

Change the battery and have a professional install a new one. If you have the expertise, you can reduce costs by replacing the battery yourself.

– Alter the Switch

One of the methods to solve the drainage problem faced by batteries is to reset battery switch. This method is available in newer car models. You can alter the switch by pressing the 12V Reset Button. After this, start the vehicle by pushing the brake and the engine’s start/stop button.

– Carry Out Battery Maintenance

You may still get the discharge warning sign after resetting the battery’s switch or starting the engine. When this happens, the next option is to perform maintenance on the battery. The maintenance is to help you keep the battery in good condition and eliminate the warning sign.

You can hire a professional, such as an auto mechanic, to help you carry out this operation. You could do it yourself by checking all connections, water level, electrolyte level, and other factors that influence battery performance.

– Evaluate the Battery and Alternator

Test the battery and alternator to see if they are in good condition. You can evaluate the battery by using a multimeter to check its voltage. A fully charged battery should be around 12.6 volts when the car engine is off and between 13.7 and 14.7 volts when the car engine is on and running. If you observe that the voltage is too low, it means that there is a problem with either the battery or alternator.

– Inspect the Coolant Level

If there is insufficient coolant, the vehicle can overheat, causing drainage problems. You should inspect the coolant reservoir to ensure it is at the appropriate line. If the coolant level is becoming too low, add more coolant to the reservoir. However, make sure it doesn’t exceed the maximum line.

– Switch on the Heater

Once you notice the warning sign indicating discharge, switch on the car’s heater. Besides heating the interior of the vehicle, the heater also helps to regulate the engine temperature. In the long run, it prevents the battery from overheating, reducing the discharge rate in extremely cold temperatures. It also helps you avoid climate control, one of the causes of battery discharge.

Replacing a Damaged Battery


Having read this guide, you should now be able to diagnose why your battery is discharging and the remedy for the problem.

Let’s do a recap of some of the points discussed:

  • You should inspect the alternator belt to check if it is damaged or loose because it can cause your battery to discharge.
  • You should inspect the electrolyte levels of the battery by checking the battery vents because low electrolyte levels can cause power drain problems.
  • You can jumpstart your vehicle to revive the engine if the car has broken down on the highway or street.
  • You should replace a damaged or weak battery with a new one if it fails to jumpstart even though it has a sufficient coolant level and a good alternator belt.

Through this guide, you can now interpret why your battery is discharging and how to fix it!

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