A battery tender is a special charging device that enables your car’s battery to charge intelligently. This device is essential, especially for owners who leave their vehicles inactive and batteries at rest for an extended period. Despite its importance, some car owners still do not understand why the device flashes different colors.
Why Is My Battery Tender Flashing?
- Your vehicle’s battery is not receiving enough power.
- There is an underlying problem with your car’s battery.
- The environmental temperature is too low to charge your vehicle’s battery.
- There is a poor connection between your car’s battery and the charger.
- The battery has not been used or fully charged for an extended period.
Battery Tender Light Codes & Troubleshooting Tips
Why Does My Battery Tender Keep Flashing Red?
If the battery tender is flashing red, the battery is below 10% and needs to be charged. Sometimes this flashing red light indicates that the charger is not working correctly or the battery is not charging properly. Therefore, you should double-check to ensure the alligator clips are correctly attached.
Also, a red flashing light on your battery tender may indicate that the charger is connected properly to the power source and your battery is drawing power correctly. Altogether, you need to be careful about a red flashing light on your battery tender. This is because sometimes, it may indicate that only the microprocessor is functional.
On the other hand, if the battery tender is flashing red fast, it may indicate that the battery is hot. That is why most experts recommend checking the battery’s temperature before plugging the charger. Additionally, avoid exposing the battery to direct heat or sunlight that could cause a rapid increase in temperature.
If the battery’s temperature is higher than usual, let it cool down for at least 30 minutes before plugging the charger. You could destroy the battery or shorten its lifespan if you charge a hot battery. It is worth noting that some lithium batteries will not charge entirely if they are too hot.
The best way to fix the flashing red light on the battery tender is by connecting your battery to a healthy charger or connecting it to a DC power source with a similar voltage rating.
Battery Tender Red Light Stays On
- The battery is not getting enough power: The main reason your battery may not be getting enough power as expected is that it is old and needs to be replaced. Also, your battery may fail to get adequate power because the alternator has gone bad. In either case, you should replace the old battery.
- The alternator is malfunctioning: Sometimes, the battery tender red light stays on to indicate that the alternator is not functioning correctly. This may be because the alternator’s belt is loose and not supplying enough charge to the battery. If your vehicle’s alternator is faulty, get it repaired immediately. Without repairs, your vehicle’s headlights will fail, the engine will stall, and the service engine light will appear.
- The vehicle is not getting enough power: The right light on your battery tender may also stay on because your vehicle is not getting adequate power due to a malfunctioning or faulty engine. Additionally, the red light may also stay on because your vehicle is not getting sufficient power from the alternator. Either way, you should take your vehicle to an auto shop to fix the engine. Note, however, that replacing an engine is expensive. It may cost you upwards of $4,000 in labor and parts to rebuild an engine.
- The battery tender is faulty: Sometimes, the problem is not with the vehicle, engine, or charger. The red light on your battery tender may flash because the device is faulty. When this happens, the battery tender will not charge the battery correctly. The best way to fix this problem is by repairing the battery tender or purchasing a new one.
- The car’s electrical system is malfunctioning: A vehicle’s electrical system usually malfunctions when there is an issue with the vehicle’s wiring or the Electronic Control Unit (ECU). If this is the case, you should get your vehicle’s wiring fixed or use an OBD 2 scanner to analyze the problems the ECU may be experiencing.
Every time the battery tender red light stays on, it indicates an underlying issue with the vehicle, engine, charger, battery, or the battery tender itself. Therefore, it is highly recommended that you hire a professional mechanic to diagnose the problem correctly and fix it immediately.
What Does the Flashing Green Light Mean on the Battery Tender?
If the battery tender is flashing green light, it means that the battery is charging and that the charger is working correctly. Therefore, you can relax knowing that your charger is doing what it is supposed to do and that the battery will be fully charged in no time.
Also, if the green light keeps flashing while the red light stays on, it indicates that the battery is more than 80% charged and is ready to use. You can also wait a few more minutes for the battery to be fully charged, as indicated by the green light turning solid green.
How Long Does It Take for the Battery Tender to Turn Green?
It takes approximately 6 to 8 hours for a battery tender to turn solid green if the battery has less than 10% charge.
What Does It Mean When Battery Tender Flashes Green Rapidly?
For instance, if you replace the battery and the fast-flashing green light changes to solid green after a few hours, it shows that your previous battery was faulty. On the other hand, if you replace the battery, but the green light keeps flashing, it indicates that the problem is with the charger, and you need to get it fixed or replaced.
Therefore, you should try replacing the charger or the battery to determine where the problem comes from.
What Does It Mean When Battery Tender Flashes Green and Never Turns Solid Green?
If the green light on the battery tender keeps flashing and never turns solid green, it may indicate that the battery is charging, but the charger is not drawing enough power from the power source. This usually happens for various reasons, including faulty outlets, wiring, and loose connection.
Therefore, ensure that the connection to the charger is secure. If the connection is secure, but the battery tender continues flashing green and never turns solid green, it may be time to replace the battery charger.
The Battery Tender Green Light Stays On
If the battery tender green light stays on, it indicates that the battery is fully charged, and you can unplug the charger. However, you can also leave the battery connected to the tender. This helps sustain the battery well and enhance its lifespan.
Battery Tender Not Turning Green
If both the green and red LED lights are off, the battery charger is disconnected from the power source. However, if the charger is connected to a power source, at least one of these lights will be on.
On the other hand, if the green light is off but the red light keeps flashing, it indicates that the charger is testing the battery. This usually happens when the battery is too hot or too cold when you plug the charger in.
If the red flashing light transforms to green and red lights simultaneously, it indicates an underlying problem. But, if the flashing red light stops and the green light starts flashing, the battery is charging.
The best way to fix the problem of the battery tender not turning green is by taking the battery out to cool down for at least half an hour before plugging the charger. You should always do this to all batteries stored in hot places.
This is because the batteries are bound to become even hotter during charge, which could pose a danger. If you notice that the green and red lights on the battery tender are off, proceed to connect the battery charger to the power supply.
Battery Tender Flashes Red and Green
Most of the time, alternating red and green lights appear on the battery tender when the battery’s terminals are connected incorrectly. Therefore, if you connect the negative charger clip to the positive battery terminal and the positive charger clip to the negative battery terminal, you will experience this problem.
It is always best to double-check these battery terminals before plugging the charger to avoid the alternate red and green flashing lights.
Battery Tender Blinking Yellow
If the battery tender flashes a yellow light, it indicates that the charger or the battery itself is defective. If the yellow light continues flashing rapidly, then the charger is not getting enough power from the power source.
On the other hand, if the yellow light remains solid, the charger is not connected correctly to the battery. It is recommended that you refer to the owner’s manual for clarity. The best way to fix this problem is by replacing the defective charger or battery with a newer version.
Battery Tender Flashes Green and Yellow
This indicates that the battery is below 10.5V, and the charger is currently in low power safety mode. If the battery does not rise above 10.5V and the two lights do not go away, you should consider disconnecting all loads from the battery and then plugging them in again.
Battery Tender Flashing Red and Yellow
If both the red and yellow lights appear on the battery tender, it indicates the battery is defective. A defective battery is a result of corroded battery terminals or sulfated batteries. The best way around this problem is to have the battery pack fixed by a professional.
A sulfated battery can easily be fixed with a slow charge, while corroded battery terminals can be fixed using a vinegar solution. If these methods do not work, consider replacing the defective battery pack.
Battery Tender Flashing Orange Light
If the battery tender flashes an orange light, it indicates that the charger is plugged in and working correctly, but the battery is not charging as it should. This usually happens when the battery is defective and needs replacing.
Consider plugging the charger in a wall outlet with matching voltage to see if the flashing orange light will stop. If it does not, it means the battery is damaged beyond repair, and you should consider replacing it with a new one.
Battery Tender Flashing Green and Orange
This indicates that the battery is too hot to start charging. Therefore, if you leave the charger plugged in, the battery will keep discharging quickly, and you also risk exploding the battery due to the excess heat. The best way to fix this problem is to allow the battery to cool down before you resume charging.
It is worth noting that a good mechanic can offer the right and reliable advice on these problems. So, if you are unsure, or need a second opinion, find a reputable mechanic with battery tender experience to diagnose and offer advice on the next steps.