Reuse Old Batteries As A Power Bank

Written By: REWA
  • Comments: 7
Reuse Old Batteries As A Power Bank

Difficulty

Very difficult

Steps

10

Time Required

1 - 3 hours

Introduction

  • CAUTION: Battery repair/modification can be dangerous. Exercise caution when following this guide. DO NOT EXPOSE LITHIUM ION BATTERIES TO WATER OR FLAMES.

All batteries have a lifespan. For example, when a phone's battery capacity is below 80%, the phone's battery life will become very short. It’s necessary to replace the new battery with a new one. For old batteries, simply throwing them away is a waste and can pollute the environment. Batteries are made from a number of materials including acid, lead, nickel, lithium, cadmium, alkaline, mercury, and nickel-metal hydride. When battery disposal is not handled correctly, the battery can leak, potentially contaminating the soil and water, and possibly harming human health. Therefore, REWA will share a way to convert old phone batteries into a power bank, turning trash into treasure.

Terminology: Anode = Positive terminal, Cathode = Negative terminal

  1. XDPhwGKwDl33Shri
    XDPhwGKwDl33Shri
    GMWQDs4bQGJyuULZ

    • CAUTION: Before starting this guide, make sure that the batteries are fully drained (0%)

    • We are using old batteries from the iPhone 7 Plus and iPhone 8 Plus. Peel off the tape on the battery protector off with tweezers.

    • Please use non-conductive tweezers to avoid short-circuiting the battery.

    • Apply tin to the anode and cathode of the battery with a soldering iron at 365°C. Heat to remove the protection board.

  2. ZBYw33W1BOAPcghM
    ZBYw33W1BOAPcghM
    nUmknaOxR1lJAZFU
    fu3eEHGYuRhbeHBZ

    • Measure the battery voltage with a multimeter. The voltages of the two batteries we have are 3.66V and 3.76V respectively.

    • As you can see, both batteries have the anode on the left and the cathode on the right.

    • Anode (Positive terminal)

    • Cathode (Negative terminal)

    • We are combining a 2900mAh iPhone 7+ battery with a 2675mAh iPhone 8+ battery and turning it into a 5575mAh power bank.

  3. TAS4XKrmecPEcvhP
    TAS4XKrmecPEcvhP
    KDElUUjT1D3EYsiW
    XmIdWAQC2LgUK4ZK

    • Apply double-sided tape to the battery and align the anodes and cathodes of the two batteries.

    • Solder together the anode and cathode of each battery with a soldering iron at 365°C.

    • Measure the voltage with a multimeter. Ensure the voltage is 3.7V.

  4. 6EFVYkXHLAKvEJeS
    6EFVYkXHLAKvEJeS
    Na3Tvwd4T1jhjBX5
    3YIcvXV4BUgbRkeo

    • Get a red wire and a black wire. Strip each end of both wires to expose the copper wire and apply tin on the copper wire with a soldering iron at 365°C.

    • Next, solder the red wire to the anode and the black wire to the cathode.

  5. QDfGxwklD2tU4yYt
    QDfGxwklD2tU4yYt
    1oxxdA4bIYELKEjv
    sc2t2HN4JQSUJDRI

    • Press down the anode and cathode.

    • Apply electrical tape, making sure to fully cover the anode and cathode.

    • Install the button on the middle frame and the power board.

  6. lGpETFfkjbyuIhsp
    lGpETFfkjbyuIhsp
    VDgPdTtIZBaItfAQ

    • Apply tin on the bonding pad of the anode and cathode with a soldering iron at 365°C.

    • Anode (Positive terminal)

    • Cathode (Negative terminal)

  7. jVZXTXsMgQEZYTtE
    jVZXTXsMgQEZYTtE
    kW1GTQRdqebIR1fC

    • Solder the anode of the battery to the anode of the power board.

    • Solder the cathode of the battery to the cathode of the power board.

  8. ikaBUK1Q3EnJLduD
    ikaBUK1Q3EnJLduD
    IZVOIuvZPaGFOd2S

    • Press the button. For this project, the power bank is 33% full.

    • Apply foam to secure the battery.

  9. RBirMZcUJfHyPrE3
    RBirMZcUJfHyPrE3
    SoEyLHHrFxsOvM1g

    • Install the middle frame to the housing and put on the bottom plastic cover.

  10. HCNFEBSBaVY3ScgR
    HCNFEBSBaVY3ScgR
    HoaB2tlUsoMcxjEB

    • Connect the phone to the power bank. The phone can be charged.

    • Connect the charger to the power bank. The power bank can be charged too.

    What kind of power bank electronics do you use for that & where can I get that? What do I have to look for when buying it?

    Florian Schinnerl -

Conclusion

If you have extra old batteries, you can increase the capacity of the power bank by combining more old batteries. Give it a try and leave a comment of your results.

Author

REWA

Member since: 24/11/20

15281 Reputation

6 comments

Do the batteries automatically stop charging at full? Like can I add iPhone batteries to the powerbank I already have?

Mark Anderson -

The batteries are "stupid", they do nothing more but taking charge. The board you solder to them is the "brain" of your powerbank. The board decides if the batteries should get charged or not, so it depends on the board you use.

To your other question:

When you open the powerbank and grab another case it´s possible to increase the capacity of your powerbank. It´s similar to the guide, but you have to test how the batteries that are already in your powerbank are connected bevor you add your iPhone batteries.

Cafugo -

@rewatech Hey, would you mind adding the power bank frame and board you bought as a required part? This guide might not work if people don't know what parts you are using

shingle -

I think they reused an old power bank and just swapped out the batteries and that this guide can apply to most off-the-shelf power banks

tayola -

I harvested a couple of batteries from old iPhones but I couldn't solder the terminals. The tin kept balling up. Then I realized that they were aluminum! Does anyone have a good method to securely connect them?

Deling Ren -

As you said you can´t solder aluminum, you would have to weld it together. If you can easily get yourself a welding tool for such purposes you can go for that method, otherwise it´s quite expensive to get such thing. If your lucky it´s only an aluminum surface with copper under it. If so you can scratch the surface a little and try the soldering method.

Cafugo -