Power banks can be real lifesavers, but sometimes they can give us headaches too. One of the most common problems with portable chargers is that their lights might blink in a specific pattern, which is not easy to understand.
Erratic light blinking can also be associated with another issue, such as the power bank not charging. In this article, we’ll be exploring some of the most common causes and solutions.
The LED Indicator Lights and Their Meaning
For a visual explanation, check out my video on this subject:
The average power bank has a set of LED lights (usually 4) that indicate the level of charge in the battery, but other important information about the power bank’s state as well.
When you connect a power bank to a power outlet to recharge it, one of the LED lights will usually blink, indicating that the power bank is taking up the charge. As you can see in the image above, the pattern in which the LEDs are light up signifies the level of charge in the power bank:
- One LED is equivalent to a charge level of 0%-25%
- Two LEDs are equivalent to a charge level of 25%-50%
- Three LEDs are equivalent to a charge level of 50%-75%
- Four LEDs are equivalent to a charge level of 75-100%.
As the power bank charges usually one LED light blinks, the last one in the series. For example, if there are 3 LEDs on, then only the 3rd one will blink until the next charging level is reached and then the 4th LED will start blinking. Once the power bank has reached a 100% charge level, all the LED lights will be constantly on, without any one of them blinking, until you unplug the device from the charger. And as you start charging another device using your power bank, the LED blinking pattern will resume designating the transfer of electricity.
Furthermore, while the power bank is not being charged, if you press the power button, all the LED lights will be briefly turned on, according to the charge level of the battery.
Other Functions the LED Lights Can Have
The battery charge level of the power bank is just one function of the LED lights, albeit the most common one. But the LED lights can also communicate other things as well. Here’s a list of some of the most common issues that they might signal:
- Charging Indication: Some power banks may use blinking LEDs to indicate charging status. For instance, a light might blink while the power bank is charging and then become steady once the device is fully charged.
- Fast Charging Indication: If the power bank supports fast charging (like Qualcomm’s Quick Charge or Power Delivery), the LEDs might change color (such as from white to green) to indicate when fast charging is active.
- Error Indication: Some power banks use LED lights to indicate problems. For instance, if all lights are flashing simultaneously, it might be a sign that there’s an error, like a short circuit or an overcharging problem.
- Power Bank Status: Beyond charging, some power banks use LED lights to indicate the power bank’s status. A light might come on when it’s successfully connected to a device or flash to show it’s in standby mode.
- Battery Health: In some advanced models, different blinking patterns or colors might be used to indicate the health of the battery, warning the user if the battery performance is degrading and needs to be replaced.
Since these signals can vary greatly between different models and manufacturers, it’s important to refer to the user manual that came with the power bank for accurate information. The manual should provide a clear explanation of what each LED light or pattern signifies for that specific model.
What a Blinking Red Light Might Indicate
We reserved a dedicated section for a blinking red light because it’s a rather important one. Because there’s no universal power bank language, it can mean different things depending on each model. Here are the most common interpretations of the red light blinking on a portable charger:
- Battery Low: The most common reason for a blinking red light is that the power bank’s battery is almost empty. This typically signals that the device needs to be recharged immediately.
- Error State: A flashing red light could also indicate a problem or error with the power bank, such as a charging fault, a short circuit, or an issue with the internal components.
- Overheating: Some power banks have a built-in safety feature that triggers a blinking red light when the device is overheating. This can occur if the power bank has been in use for an extended period if it’s charging a device while being charged itself, or if it’s been left in a hot environment.
- Overload: If a device that draws more power than the power bank can provide is connected, the power bank might blink a red light to signal that it’s overloaded and can’t charge the device.
Again, each power bank is different, so for the exact interpretation of a red LED blinking on your power bank, please consult the user manual. You can also get in touch with me via the comment section below and I’ll do my best to figure it out.
LED Lights Blinking But the Power Bank Won’t Charge
In some cases, you might notice that the power bank is not charging despite being plugged into a power source, with the LED indicator lights flashing.
It may happen that after waiting several hours, or even a day, your power bank doesn’t charge fully. It may only charge partially, or not at all. You may wonder if this signifies a complete failure of your power bank, or if it’s just a minor issue.
A multitude of factors can contribute to such a scenario. To help you understand what might be going wrong, we’ve compiled the following checklist that you can use to troubleshoot and diagnose the issue.
Possible Causes and Troubleshooting Checklist
In order to pinpoint the exact issue your portable charge might have for not charging as expected, you should check different possible failure points. It may be that the problem is a very minor one that’s easy and quick to fix. But it may also be something more serious that might not even be fixable. Here’s what to look for:
1. Reset the Power Bank
Some power banks come with a reset function. In case your power bank has this function, use it. This may clear any temporary issues that are stopping the power bank from charging. The method to reset differs by brand and model, so consult your power bank’s manual for specific instructions. This usually fixes the majority of charging issues. If it doesn’t work, please proceed with the steps below.
2. Check if Power Cables Are Properly Connected
An insufficiently inserted power cable could be the source of the problem, resulting in an unstable connection. Verify that both ends of the plug securely fit into their respective charging ports.
Additionally, keep an eye out for debris (like dust, sand, lint, or dirt) that might be lodged in the charging port. This could disrupt the connection, so ensure the port is clean, but do so gently to avoid damaging any components.
3. Use a Different Charging Cable
If the connections are secure but your power bank still isn’t charging, the power cable itself might be the issue. Some cables are of lower quality, impacting the charging rate.
Also, if the cable doesn’t support the fast charging technology that your power bank requires, it could result in undercharging. In this case, trying a different power cable might resolve the issue. As a general rule, try to use the original cables the portable charger came with, unless they are visibly damaged.
Sometimes even the slightest pinch can damage charging cables. I accidentally squished numerous charging cables with the foot of my stool as I was working at my desk. These things happen almost on a daily basis, but we seldom think that they might have an impact on the cables themselves.
4. Don’t Charge Your Power Bank Via a Laptop’s USB Port
When charging your power bank, it’s crucial to use a main electric power outlet rather than a laptop’s USB port. The latter usually only output around 0.5 A, which typically isn’t enough to efficiently charge a power bank.
This also holds true for USB hubs that don’t have fast charging protocols. A lot of time people are not aware that different power sources have different power outputs, so they expect the same results regardless of what they’re using. But simply charging a power bank via a low-powered laptop’s USB port can add up to 10 hours to the total charging time, especially if it’s a high-capacity power bank.
5. Experiment With a Different Wall Charger
The adaptor you’re using could be faulty or delivering too low an output for the power bank to charge. Consider trying a different adaptor. If this resolves the issue, it’s a clear sign that your original adaptor is faulty and needs replacing.
Also, please make sure that the chargers are compatible with the power bank when it comes to charging technologies. For example, you’ll reach the best results if both the charger and power bank feature the PD (Power Delivery) protocol.
6. Test with Different Devices
Connect different devices to the power bank to rule out the possibility that the issue is with the device you’re trying to charge and not the power bank itself. One common issue is that people try to charge low-power devices such as fitness bracelets, Bluetooth headphones, or smartwatches using the regular power mode. In order to charge these devices you need to activate the trickle charging mode (also known as low current charging). Please refer to your user manual on how to do that, since different models have different ways to turn trickle charging on.
Another important mention is that not all power banks come with a trickle charging feature. So if your power bank can successfully charge a smartphone for example, but will not charge a low-power device and the user manual doesn’t mention anything about trickle charging, then the power bank model that you have doesn’t support this feature.
7. Check for Physical Damage
Inspect your power bank for any signs of physical damage. If it has been dropped or exposed to extreme conditions, there might be internal damage that is not immediately apparent. Another important clue to look for is a swollen or bulging battery. This might not be immediately obvious if it’s in the early stages, but the power bank might be slightly rounded and easily rocking side-to-side. The casing edges might even come apart slightly or very obviously like in the example below:
All these symptoms are pointing to an overcharged battery that has expanded. In this stage Li-ion batteries can be dangerous, read more about it here.
Troubleshooting Did Not Solve the Issue?
If you followed the suggested troubleshooting list and the problem still persists then there are two main possibilities:
- There is an internal circuitry problem. This can have many causes from improper usage and/or storage to a manufacturing defect.
- The battery has reached the end of its life. This would be the case if you had the power bank for a while now and have charged and discharged it hundreds of times. Generally speaking, Li-ion batteries start to lose about 20% of capacity after the first 500 charge/discharge cycles and will keep degrading as they’re being used. At around 2500 cycles you can expect the battery to be completely unusable. Please bear in mind that these are just some rough estimations though, the actual battery-depleting process can be shorter or longer based on a wide array of factors.
Here’s What to Do if Your Portable Charger’s Battery Died
If you’re sure that the main issue is a dead or faulty battery, then here’s the best plan of action to take:
- Check your warranty. If your power bank is within the warranty limit, then get in touch with the store that you bought it from for further information. In some cases, you might get a replacement product, a free repair, or even a refund.
- Get in touch with customer support. Larger manufacturers such as Anker, RAVPower, or Aukey have dedicated support teams that might be able to help you with the issue. They might be able to help even if your warranty is expired. However, less popular manufacturers such as Pocket Juice, BlackWeb, or Mophie don’t have such extensive client support systems in place, so getting in touch with a representative might be somewhat more difficult. But even so, it’s would still be worth trying to get in touch with a company representative.
- Have the power bank serviced by an electronics repair shop. If you have such a shop nearby it’s always a good idea to take the power bank in for a checkup. A professional can quickly pinpoint the problem, which sometimes can be very trivial. It happened to me once when I thought that my smartphone was dead because it wasn’t charging anymore, so I had it checked. It turns out the charging cable I was using did not work and the phone was completely fine. Had I followed the troubleshooting suggestions above, I would have discovered the issue myself, but in this case, the friendly people at the service shop quickly figured out what was wrong.
- Safely dispose of the defective device. If nothing else worked and the power bank is unsalvageable, the best thing to do is to safely dispose of it. The only secure way to do that is to take it to a designated collection point for small electronics and/or batteries. This way you can ensure the battery will get recycled and will not end up in a landfill where it would potentially release toxic substances or even start garbage fires.
Alternatives to LED Lights on Power Banks
As an outro, I wanted to point out that LEDs are not the only option when it comes to power banks. In fact, they’re the most prevalent solution out there because it’s the cheapest and simplest one to create. So the majority of the manufacturers go with this one out of commodity. But there are other options out there as well, which I would recommend over the classic LED lights.
LCD Display Power Banks
Some power banks have an LCD (Liquid Crystal Display) screen which can provide a range of information. This could include the exact percentage of battery charge left, input/output voltage, charging current, fast charging status, or even error messages. An LCD display provides more precise information than LED lights.
Example: Omincharge Omni 20+
Digital LED Display Power Banks
These displays work similarly to an LCD screen but use LED technology to provide numerical or alphanumeric information about the charge level, usually in terms of a percentage.
Example: INIU BI-B61
Blinking lights on a power bank can have a lot of different meanings. They generally refer to the charging state of the battery, but they can also communicate different issues. Since not all power banks are the same, it’s always a good idea to check the user manual for the exact model you have. In case you lost it, you can generally find it online by doing a dedicated search.
If that doesn’t work, hopefully, this article can help you out by giving you some troubleshooting ideas and some general suggestions. In case you have some specific questions or requests, don’t hesitate to reach me in the comments below or via my YouTube channel.