20,000mah Battery Power Bank Problem Solved

By on July 13, 2015
power bank repair

 

 

 

 

 

 

 

I bought a 20,000mah battery power bank from my relative for my family members to use it. I thought we will use this power bank but the fact is we rarely use it. In fact I was totally forgotten about this power bank. When I found this power bank, I realized that it already never been used for more than 6 months! I tried to turn it On and it can’t be turned On. I even tried to charge it using the handphone charger, the result was the same.

battery power bank repair

power bank repair8

I guess I have left it too long and the battery power could had been depleted.  Once the battery voltage is too low or no voltage at all, it would be hard for the charger to charge it. It has to have some minimum voltage in order for the handphone charger to charge it.

power bank circuit board

power bank board

I opened up the cover and measured the batteries and it was zero volt (flat)! The batteries are connected in parallel and are from the Lithium Ion type (18650). Each battery is rated as 3.7 volt.

power bank parallel

From the experience of flying small RC Helicopter that use the lithium polymer batteries, I knew that once the battery is flat or too low, one has to use an external charger to slowly charge the battery until it reach certain level of voltage before you can use back the RC helicopter remote control (that come with a built in charger) to charge it.

So in this case you need to charge the Lithium Ion battery first using the Lithium Ion charger before you can charge it using the handphone charger. Since I do not have the Lithium Ion charger, I had to try it out by using the GT Power battery charger and set to Ni-MH mode (Nickel Metal Hydride).

I have chosen low amp slow charge. After couple minutes of charging I could see from the charger display screen the voltage is slowly rising and the batteries were not hot. I continued to monitor the voltage and the temperature of the battery even after more than half an hour and it seems all to be in good condition. By the time it reached one hour, the battery voltage already increased to 3.129 volt.

power bank repairing

I continued to charge it for another half an hour before putting everything back and turn the power bank On.

gt power charger

power bank repair5

Guess what? Not only it can be powered On, it can also be charged by using the handphone charger. Once the power bank is fully charged by the handphone charger, I then connected it to my phone and sees if it can sustain the power draw from my phone. The result was great.

power bank repair3

It can charge my phone and even though my phone battery already full, I still could see there are still power left in the power bank by looking at the number of LED bar at the top right-see the photo below.

power bank repair9

Note: If you have a NI-MH charger that can’t be set to low amp slow charge then do not use it because a fast/high current charge can destroy the battery or even cause explosion. If you are not sure about this, I suggest that you buy the Lithium Ion charger.

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64 Comments

  1. Albert

    July 13, 2015 at 3:09 pm

    Hi Jestine, I have an old Solar Power Bank Charger that is defect. Probably a very low voltage battery inside too. But in this older and different Solar charger there probably is no identically electronic controller. But after reading your article I must try to repair it by very slow amp charging if it is indeed also some kind of Li-ion type Battery.

    Likes(2)Dislikes(0)
    • Jestine Yong

      July 13, 2015 at 3:46 pm

      HI Albert,

      Yes you should try it.

      Jestine

      Likes(3)Dislikes(1)
      • Albert

        July 13, 2015 at 9:04 pm

        Hi Jestine, Bad luck for me. My Solar USB charger with 1350mAh 3.7V Battery inside seems to behave very strangely when I insert the 5V output cable. And WORSE this TOM-TEC SC0508 has shorting SMD components on its pcb I can't trace.
        One U2 SOT23-5 component reads "7NFD" and the other "007F". I only see a simple SMD NE555 is part of the Charger input with one S8550, one S9015 and 2 leds. With of course the necessary resistors and a few capacitors, and 2 diodes. So no repair succes for me I am afraid.

        Likes(0)Dislikes(0)
  2. Yogesh Panchal

    July 13, 2015 at 4:22 pm

    Sir,
    Have you ever try to charge this type of battery with the help of bench DC Lab Power Supply.

    Likes(2)Dislikes(1)
    • Jestine Yong

      July 13, 2015 at 4:46 pm

      Hi Yogesh,

      Every rechargeable batteries has their own characteristic. This means you need special charger for different type of rechargeable batteries. I have tried using the dc lab power supply to charge on Lithium polymer battery and it will not work.

      Jestine

      Likes(2)Dislikes(0)
  3. sagar sen

    July 13, 2015 at 5:32 pm

    sir, somebody told me that when li ion battery was not working ,put it into the freezer.

    Likes(1)Dislikes(1)
    • Jestine Yong

      July 15, 2015 at 12:40 pm

      Hi Sagar,

      There are some info in this link :

      http://chemistry.stackexchange.com/questions/5471/reviving-li-ion-battery-in-freezer

      Jestine

      Likes(1)Dislikes(0)
  4. Corriete

    July 13, 2015 at 9:46 pm

    thanks for this info sir.now do you knopw what causes mobile or smart phone batteries to lose charge so quicy after charging? e. i used the battery when was new for 3-5 days before charging again but after 6-8 months it has to be charged like after a day or two. even seen that same thing happen to the mosquito charger batteries. do you know what causes that and is there a solution apart from buying a new one since new batteries are not readily available in this part of the world? thanks .

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 14, 2015 at 11:01 am

      HI Corriete,

      Is your battery original?

      Jestine

      Likes(0)Dislikes(0)
  5. Andre Gopee

    July 14, 2015 at 4:49 am

    Hi Jestine, this is very important to that not all batteries can be charge by the same charger. Job well done. Thanks for the information.

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 14, 2015 at 11:00 am

      HI Andre,

      You are welcome.

      Jestine

      Likes(0)Dislikes(0)
  6. Robert Calk

    July 14, 2015 at 6:43 am

    Good job, Mr. Yong. Thanks for the article.

    Likes(1)Dislikes(0)
    • Jestine Yong

      July 14, 2015 at 10:59 am

      HI Robert,

      You are welcome.

      Jestine

      Likes(0)Dislikes(0)
  7. Gerald

    July 14, 2015 at 4:22 pm

    Hi Jestine,

    This was an interesting post, thanks for sharing. Batteries always fascinated me since my childhood. I remember my grandfather pulling apart his tractors battery, scrubbing the lead plates then putting then back together, poured some distilled water, a bit of acid and the battery was like new. It looked like magic to me!

    Today’s batteries are much trickier. It seems that the way to recover a dead battery depends on the type of battery, its condition and… the phase of the moon? It still looks like magic to me.

    Something is sure, as illustrated in your article, is that brutal force with high current doesn’t work. A low current until it reaches the voltage and then you can use the normal charger. It worked for me… some times.

    Cheers,
    Gerald

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 15, 2015 at 9:31 am

      HI Gerald,

      Yes, today's battery you need different type of charger for them. You are right always use low current first until it reached the voltage and then use back the normal charger to charge it.

      Jestine

      Likes(2)Dislikes(0)
  8. reza

    July 14, 2015 at 6:10 pm

    Dear Jestine Yong
    thank u for this good article.

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 15, 2015 at 9:27 am

      Hi Reza,

      You are welcome.

      Jestine

      Likes(0)Dislikes(0)
  9. Corriete

    July 14, 2015 at 7:28 pm

    yes sir the battery is the original.

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 15, 2015 at 12:51 pm

      Hi Corriete,

      In this case, you may need to check with the seller to see if your phone need to upgrade to the latest version of software and have your new battery check by them.

      Jestine

      Likes(0)Dislikes(0)
  10. Muhammad amjad

    July 15, 2015 at 1:27 pm

    I read your articles from many years but this is my first comment, I appreciate all your articles. They are very informative and suitable for technical peoples,thank you.

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 15, 2015 at 3:13 pm

      Hi Muhammad,

      You are welcome.

      Jestine

      Likes(0)Dislikes(0)
  11. Humberto

    July 15, 2015 at 8:18 pm

    Hi Mr. Jestine Yong, you are 100% right regarding every rechargeable battery has its owns characteristics and need a type of charger, and most of the time people violate this topic. Thanks for the article.

    Likes(2)Dislikes(0)
    • Robert Calk

      July 20, 2015 at 2:55 pm

      I bought an Intellicharger-i2 from Ebay that recognizes the type of battery( Li-ion or Ni-MH)and size you put in it, and charges it accordingly. Each battery slot has it's own circuitry so I can charge 2 different types of rechargeable batteries at the same time. They have an Intellicharger i4 that has 4 battery slots.

      Likes(2)Dislikes(0)
      • Jestine Yong

        July 20, 2015 at 3:09 pm

        Hi Robert,
        Saw the info in Ebay and seems to be a very good charger.

        Jestine

        Likes(1)Dislikes(0)
        • Robert Calk

          July 21, 2015 at 6:21 am

          Yes, mine has been working great now for several months. I would like to have one similar to the one you use in the article also. I'm not sure if the Intellicharger i2 would work on a completely flat battery though.

          Likes(0)Dislikes(0)
          • Jestine Yong

            July 21, 2015 at 8:23 am

            HI Robert,

            Mine can charge on the Lithium Polymer and when the batteries are welded in parallel. It is hard to remove the welded joints and then take the single battery out and charge on the Intellicharger i2 charger. As for the flat batter, not all flat battery can be saved. If it is a new one then chances is very high it can be saved.

            Jestine

            Likes(0)Dislikes(0)
            • Robert Calk

              July 21, 2015 at 2:24 pm

              Yes, I would have to separate them for charging. I have a book about different types of batteries and other ways to revive dead batteries that I won't mention here for fear that someone may get hurt.

              Likes(0)Dislikes(0)
              • Robert Calk

                January 30, 2016 at 8:14 pm

                Hi Mr. Yong,
                I bought a new GT Power X-Charger 606D.
                It is nice and charges many more types
                of batteries, and has many more capabilities
                than the intellicharger i2.

                Likes(0)Dislikes(0)
                • Jestine Yong

                  January 30, 2016 at 11:22 pm

                  HI Robert,

                  Good to hear that. You have made the right choice because the GT brand is very reliable.

                  Jestine.

                  Likes(1)Dislikes(1)
  12. Aminu Umar Aminu

    July 18, 2015 at 10:05 pm

    Thanks alot Jestine Yong

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 19, 2015 at 6:24 pm

      Hi Aminu,

      You are welcome.

      Jestine

      Likes(0)Dislikes(0)
  13. bhadran

    July 19, 2015 at 1:43 pm

    Dear jestine

    How R U ? Hope Fine
    The article which you sent me is very usful for everybody this is a new information for me there is deferent type of charger is using for deferent battery.thanks lot
    Warm regards
    Bhadran
    India

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 20, 2015 at 10:26 am

      HI Bhadran,

      I'm fine thanks and glad that you liked the article.

      Jestine

      Likes(1)Dislikes(0)
  14. Atief

    January 29, 2016 at 1:34 pm

    Hello sir, since i have no knowledge abt amp n etc. It is difficult for me to follow ur instructions. The problem with my PB is that it shows led light when I connect it for charging with my phone's charger but once i remove the charger is seems dead. Pressing the power bottom just shows a blink of led. Plz help me

    Likes(0)Dislikes(0)
    • Jestine Yong

      January 30, 2016 at 3:30 pm

      Hi Atief,

      How long you have been using the PB? Have you removed the cover and check the batteries DC voltage.

      Jestine

      Likes(0)Dislikes(0)
  15. stewart

    February 18, 2016 at 11:25 pm

    Sir i have the same power bank, but the problem when i connect the battery on the board the ic become very hot and then the battery drop to 0volt after some hour, i want to change the ic but problem have no number on the ic, if it possible you can tell me what is the num of the ic,

    Thank you

    Likes(0)Dislikes(0)
    • Jestine Yong

      February 20, 2016 at 12:12 pm

      Hi Stewart,

      They have scratch off the IC part number so I would not know what part number they are using.

      Jestine

      Likes(0)Dislikes(0)
  16. Robin

    March 19, 2016 at 12:30 am

    sir.my power bank circuit is getting charged well but is not
    Discharging

    Likes(0)Dislikes(0)
    • Jestine Yong

      March 22, 2016 at 2:48 pm

      Hi Robin,

      Do you mean your type of power bank can select to discharge on its own? How long have you been using it and how many mah for the battery?

      Jestine

      Likes(0)Dislikes(0)
  17. Gaurav Kale

    August 2, 2016 at 3:35 pm

    How do I open the battery cover?

    Likes(0)Dislikes(0)
    • Jestine Yong

      August 2, 2016 at 5:56 pm

      Hi Gaurav,

      Use a thin and flat metal piece. You can make one from a split tweezers.

      Jestine

      Likes(0)Dislikes(0)
  18. Onesmus Shaanika

    August 7, 2016 at 7:43 pm

    Hi
    My brand new power bank that I have only used twice suddenly fell into a frozen state. Its torch light is on, the blue battery indicating light is on and nothing switches off. It wont charge the phone, neither does it charge itself when pugged in. What could be the problem how do I solve it?

    Likes(0)Dislikes(0)
    • Jestine Yong

      August 8, 2016 at 8:02 pm

      Hi Onesmus,

      Check the battery voltage first. If it is ok then possible the circuit board have problem.

      Jestine

      Likes(0)Dislikes(0)
      • Onesmus Shaanika

        August 16, 2016 at 4:20 am

        Voltage is probably fine. the torch and blue light has been on for two weeks now but the bank doesn't respond to any connected cable, for charging it or the phone. can the circuit board be repaired?

        Likes(0)Dislikes(0)
        • Jestine Yong

          August 19, 2016 at 2:22 pm

          Hi Onesmus,

          Kindly let me know what is the voltage of the battery.

          Jestine

          Likes(0)Dislikes(0)
  19. Reekes

    August 20, 2016 at 10:29 am

    HI justine.
    I have a question. But first ill tell some experience. I am using a galaxy s3 phone before and was successful at converting its internal battery to directly use a power bank. Its original battery has only 3 terminal so directing the powerbank is easy. Now i want to do the same with my new phone only this time the phone uses 4 terminal battery. I did the same thing like i did to my s3 but it didnt worked. So my guess is it had to do with the 4 terminal. So my question is. Can i put the power bank in parallel to the original battery to make it work? But i am hesitant for it might explode im afraid. Is there any work around i can do to direct my phone power usage to a power bank instead from its original battery?
    Note reposting as i didnt saw my comment appearing

    Likes(0)Dislikes(0)
    • Jestine Yong

      August 22, 2016 at 10:30 pm

      Hi Reekes,
      I have not personally tested such configuration before thus I can't give to you an immediate answer. I suggest that you check the 4 terminals which one is negative, positive, Thermistor and ID pins. A wrong connection will cause it to explode. I wonder why you want to put your new phone in risk? There was a phrase 'if it ain't broke don't fix it'

      Jestine

      Likes(1)Dislikes(0)
  20. vilereed

    August 23, 2016 at 9:03 pm

    Hi Jestine, thanks for the reply. you were correct that the battery uses an I'd terminal for battery data purposes. But I'm not trying to fix it anyway it's just I'm trying to solve the issue of battery being power drained too fast and to solve the longer usage of the phone that is why I am trying to fake the battery of the phone in using the powerbank as it's source directly. to give you an update I was able to do it. I managed to set the power bank as the source. now I can use the phone longer because the power bank has power large enough to run my phone under heavy use for the whole day without ever replacing or draining too fast. however the problem is when I'm turning on the camera it suddenly turns off. so by accident if the camera was turned on it will stop. I don't have the solution yet. but I can use the phone 5 times longer than before with it's original battery. Because I'm a nonstop gamer so I need longer power.

    Likes(0)Dislikes(0)
    • Jestine Yong

      August 24, 2016 at 9:53 pm

      Hi Vilereed,

      Ok noted and Congratulation! Hope you also find the solution why the phone will shut when it is On.

      Jestine

      Likes(0)Dislikes(0)
  21. Lanre

    August 24, 2016 at 6:34 am

    Hello jestine,my power bank fell down today an since its not charging but it's still charging my phone

    What should i do?

    Likes(0)Dislikes(0)
    • Jestine Yong

      August 24, 2016 at 3:44 pm

      Hi Lanre,

      Open it up to see if there is any broken connection especially the circuit board.

      Jestine

      Likes(0)Dislikes(1)
  22. Tahir

    December 6, 2016 at 12:27 am

    hi Justine. I need help for my batt bank. I replaced the batteries and it worked fine for some days, but later it doesn't power on. it will power on for just 2 or 3 seconds and shuts off. rest of the functions are working fine, I mean the torch, battery level, solar charging and usb charging. it doesn't power on.

    Likes(0)Dislikes(0)
    • Jestine Yong

      December 9, 2016 at 5:35 pm

      Hi TAHIR,

      Since you have replaced with the same type of batteries and there was still problem this means the mainboard have problem. For battery bank that is hard to find the schematic, it is hard to troubleshoot it due to limited information. What you can do is to check every of the ICs in the main board for proper DC supply voltage. If all the DC supply are good and stable then you may need to direct replace the ICs and retest. Some of the ICs are quite hard to find and if this battery bank is cheap, getting a new one would be much cost effective unless if you have the time to find out the fault.

      Jestine

      Likes(1)Dislikes(0)
      • Tahir

        December 11, 2016 at 4:59 pm

        Yes the problem lies in the main board. But unfortunately the ic number doesn't appear on the ic. When I connect the solar panel, it starts working provides the output. But if the Solar Panel is tilted towards darkness. It stops the output. Now I tried a different method. I connected a 4.7K resistor between the battery positive and solar positive. It plays a cheat upon the main ic, and starts working, but at the same time, the main ic gets the voltage at Solar point so it shows the false charging.

        Likes(0)Dislikes(0)
        • Tahir

          December 11, 2016 at 5:02 pm

          This is the exact model I m talking about....

          http://www.bookthewish.com/cross-3-in-1-solar-charger.asp

          Likes(0)Dislikes(0)
        • Jestine Yong

          December 13, 2016 at 10:25 pm

          Hi Tahir,

          Ok noted. As mentioned before there is very little information about this kind of mainboard. The only way to troubleshoot it is to check on the dc supply voltage, smd components and direct replacement of the ICs provided if you can find such ICs and the price is reasonable.

          Jestine

          Likes(0)Dislikes(0)
  23. Sanjay poonia

    January 20, 2017 at 11:00 am

    Sir ,
    When i start the powerbank its light bright only once .

    It works only 2-3 second
    After this it stop itself .

    Where is problem

    Likes(0)Dislikes(0)
  24. Eva Bernaldez

    July 25, 2017 at 1:56 pm

    hi sir i just want to ask if what causes the lcd screen or led screen disappeared slowly i cant see the number anymore..what canni do?

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 27, 2017 at 10:41 pm

      HI Eva,

      It can be due to bad lcd screen, dry joints, loosen cable/connector, missing dc supply voltage and many more.

      Jestine

      Likes(0)Dislikes(0)
  25. amal

    August 6, 2017 at 4:47 pm

    Sir I'm having a power bank of 50000mah(mentioned on and after charging power bank it shows fully charged (led blinks) and while charging the phone it shows low battery suddenly not get proper output

    Likes(0)Dislikes(0)
    • Jestine Yong

      August 9, 2017 at 2:21 pm

      HI Amal,

      If you have use this power bank for more than a year and a half chances is high the batteries could be weak already. If the batteries are good then it will be the mainboad fault in which it is hard to repair due to less or no information on this type of mainboard.

      Jestine

      Likes(0)Dislikes(0)
  26. Don Daniel

    September 19, 2017 at 6:49 pm

    Good day sir, pls sir i have a power bank circuit here, it is not functiong well so when i yry testing the battery terminal on continuity mode, my multimeter beeps continuously, pls what could be the cause sir. thank u

    Likes(0)Dislikes(0)
    • Jestine Yong

      September 21, 2017 at 11:12 am

      Hi Don,

      You cannot test the battery using continuity mode. You need to test it using DC voltage mode.

      Jestine

      Likes(0)Dislikes(0)
  27. Ramesh Maladeniya

    December 21, 2017 at 11:09 pm

    I have purchased MI 20,000 map power bank. I have charged it 100% on last Sunday and didn't use it until Thursday. When I checked the power bank on Thursday it has only 25%-50% remaining power. Without using the power bank how come the batteries got drained. Please clarify this to me.

    Likes(0)Dislikes(0)

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