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 functions
Most power banks have 4 small LED power indicator lights that provide information regarding the battery charging state.
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 the picture shows, each of the LED lights indicate the current charge of the battery:
- 1st light blinking means it is charged between 0%-25%
- 2nd light blinking means is charged between 25%-50%
- 3rd light blinking means it is charged between 50%-75%
- 4th light blinking means it is charged between 75-100%.
These lights usually blink during the recharging process. They also blink if you want to monitor how much power is left by pressing the power button, a feature that almost all power banks have. When you see 4 LED lights glowing steady, it means that the unit is fully charged.
Conversely, when you connect your mobile phone to the power bank, the LED indicator will start flashing, indicating the following:
- All 4 lights are blinking means it has between 75%-100% charge remaining.
- 3 blinking lights mean it has between 50%-75% charge remaining.
- 2 blinking lights mean it has between 25%-50% charge remaining.
- Only 1 light blinking means it has between 0-25% charge remaining.
At this point, you should disconnect the mobile phone, preventing the power bank from discharging completely, as it may damage its battery, especially when done repeatedly.
LED lights blinking but the power bank won’t charge
In some cases, you might notice the fact that the power bank is not charging even though it’s plugged in, and the LED lights are blinking.
In other cases, you wait for several hours or a day, and the power bank just won’t charge, or it may charge halfway or somewhere in between, despite the lights showing it is fully charged. Something is not right.
Does this mean that the power bank died completely, or is it something trivial? The truth of the matter is that this situation has no simple yes/no answer.
There are a lot of different scenarios that might cause this issue. This is why we’ve created the checklist below, which you can use to self-diagnose the problem.
Possible causes and troubleshooting checklist
The problem may be a minor fault that can be easily taken care of, or it can be a serious issue that requires professional repair. It could be one of the following problems:
1. Make sure that the power cable is fully inserted
It may happen that you simply didn’t fully insert the power plug in the charging port thus creating a faulty connection. Check the plug and see that it fits the socket snugly. Also, make sure that the power connector on the power bank is inserted fully in its socket.
Make sure that there isn’t any type of debris in the charging port such as dust, sand, dirt, etc. Sometimes impurities stuck in the socket can cause a bad connection. Just make sure to do it carefully or you might break one of the pins.
2. Try using a different power cable
If the connections are snug and the power bank is still not charging then it is possible that the power cable is bad. Some power cables can be of really low quality, which has a direct effect on the charging rate.
It might also be the case that the cable does not support fast charging technology as the power bank requires, which is why it is undercharging. If this occurs, simply change the power cable and try again.
3. Charge the power bank via a wall socket, not via a laptop USB
Make sure that you are charging the power bank from a main electric power outlet and not via a computer, as usually the output current from a computer USB port is around 0.5 A, which is not sufficiently high to charge the power bank.
4. Try charging the power bank with a different adaptor
It may be possible that the adaptor you’re using to charge your power bank either has gone faulty or outputs such a low value that the power bank is not charging. Try using a different adaptor instead. If this works, then you can be certain that the charger is faulty, and you should replace it.
5. The power bank battery might have died
If your power bank does not appear to be getting charged as no lights turn on when connected to a power source nor it charges your mobile phone when connected to it, then it is likely that the power bank has suffered an internal failure.
If the power bank suffered a hard shock like a fall or was left in a hot environment for a long time, there is a possibility that its internal circuits have failed.
If you have used your power bank quite frequently, then the batteries may have completed their life. Power bank batteries have a life of 300 to 1000 power cycles, depending on the brand and model.
In all such cases, the problem is serious, and the power bank should be repaired professionally.
What to do if your power bank died
If you made sure that there is no other possible cause for the problem, and the power bank battery died, here’s what you can do.
- Check your warranty. Most power banks come with a 12 – 36-month warranty. You might be able to get your unit replaced. For this to work, most likely, you’ll need to have the purchase receipt and/or the warranty certificate.
- Check with the producer. Bigger companies such as Anker, Aukey, and RAVpower have websites and client service centers that might be able to help you. Get in touch and see if you could maybe get your unit replaced. Unfortunately, smaller producers and subsidiaries such as BlackWeb, Protable Juice, or Mophie don’t have such reliable customer service networks.
- Take the power bank to your local electrical repair shop. In many cases, your local repair shop can fix your portable charger within a few hours. It’s always worth going for this solution when you run out of options as it’s better to get an item fixed than to buy a new one altogether. The trouble with this is that once the power bank is opened by a third-party service, you’ll lose your warranty rights.
- If all of the above did not work, there’s just one option left: to dispose of your power bank. However, please do so in an environmental-friendly manner, as batteries contain a lot of toxic substances that may harm the environment. Bring it to a local recycling center that has a dedicated service for processing batteries.
Some helpful tips to keep your power bank healthy
- Always use the cable supplied by the vendor or any other short-length good quality USB cable.
- Avoid charging the mobile phone with the power bank while loading your power bank from a power outlet at the same time.
- Avoid leaving your power bank in a hot place, such as a parked car in summer.
- Only charge devices that are intended to be used for that model of the power bank.
Never overcharge or fully discharge Lithium-ion batteries
Lithium-ion batteries are designed in such a way that they are charged to just below their full capacity before they attain the full voltage. They can discharge up to a certain voltage below which its internal circuits stop further discharge to protect the batteries. Overcharging or fully discharging reduces the life of Lithium-ion batteries.
If the power bank batteries are totally discharged due to any reason and the voltage falls below a threshold, it may be difficult to recharge them. In such cases, give it more time, connected to a power source, until it slow trickle charges to a certain threshold level then starts its normal charging sequence.
Check our past article, for a deeper understanding of Lithium-ion batteries.
When the light indicator of your power bank is blinking, but it’s not really charging is a cause for concern as it might be a sign of malfunction. However, it doesn’t mean that the power bank is already broken, and it’s time to get a replacement; it could be just a case of wrong power bank-charger pairing.
Nonetheless, if your power bank is not working properly but it can be fixed by changing the cable or the charger, then do it yourself. However, if the issue persists, you should get it repaired by a professional. Do not try to open the case of the power bank and try to repair it yourself, as it will void a valid warranty.