How to Use Phone Without Battery




Introduction: How to Use Phone Without Battery

I made this for my next project.

How to connect phones with 4 pins, take a look into comments.

Step 1: "Battery"

I took pins from SD card adapter and glue them with Super Attak glue on piece of wood.

I used 82kΩ resistor.

Step 2: Power Supply

After couple of months I can say this is perfect power supply. It has enough power and it does not go hot! I bought it on Ebay for some bucks

Lithium Charger Step down 5A 5V-32V to 0.8V-30V Power Supply Module LED Drive 5A

Step 3:

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49 Discussions


This is a nice project! I want to do a similar thing: I have a Samsung Galaxy Ace GT_S5830i phone with an almost dead battery. I could use it without a battery, but I'm not sure what's the difference if I want to use the USB socket of the phone for energy supply. So I'd like to avoid using a new cable for the power.

1 reply

First I need to apologize to you for really late answer:(
Batteries are dangerous, so that is the reason why I made so wird project and remove battery from my phone.


Thanks for the idea. I'd like to do the same with an S5 ( SM-G900WB )

but I have 4 battery terminals and not sure what should be the resistor value..

Thanks in advance. :)

11 replies


good question:)

If you have pins V+, ? , V-, ? I will try to put resistor on the middle one (between V+ & V-).

Yea, the 4th pin is for the NFC... not sure for the 3rd one is for termals.. but..
Once I found the battery good pins, how should I mesure the right resistor value ?

Thanks !


I got all my wires right, got a great step down power supply(from a 5volts to 3.85) but the phone seams to ignore the resitor 82K... the ''battery'' slowly drains.. have you experienced the same thing ?

Fresh plug I have about 68%... going down slowly.

I guess I should try a different resistor value ?

Any other idea ?

Hi, would you please paste the picture of the correct pins with wires and resistor for 4 pins. I put 82k resistor between v+ and v- but it not work. My phone is samsung S2(I9100), thanks a lot!

I think your power supply is not enough powerful.

You need more watts (amperes)

Paste link of your power supply.

you where right. I was running my DC converter from usb 5v down to 3,85V then 4.0V

Right when I plugged into a computer 12v source, I got 100% with only two wires didn't plugged the resistor at all.

it's now on the bench with flashlight and 3hours long youtube video to try to drain it.. I think I'm good now.

Thanks for the kind help.

of course didn't work ok, USB is only 0.5A or max 1A, but you need 5A;)

Please paste some pics what did you do;)

Here is the one I've bought.

I've also increased to 5v flush. now I have like 80% battery..

if I unplug and replug, I get the 80% back...

but I'd consuming.. I'm watching 'longest youtube video' with flash light open to drain at maximum and see what happens when it reaches 1% or 0%..

I'm thinking it might be the 82K resistor ....

note my battery has 4 leads.. ( with one I believe to be the NFC )


power supply looks enough powerful...

Buy the same one like me. So we will see if the problem in phone, resistor or power supply.

How did you adjust the power supply unit? Which screw does what? Without load it gives out always approx 5 volts, and i somehow hesitate hooking up phone to it without first making sure i have correct voltage.

Also, what's the resistor value for the extra pin? Any hints on choosing it?

4 replies

One screw is for Voltage, another is for load regulation (amperes).

If you always have 5V output, you doing something wrong or is your power supply broken.

Don't put 5V in your phone. Take a look on battery how many Volts have!

I have the same problem like you with some very similar power supply (LM2596). I have 3 at home from different seller, and no one works.

What type of volt meter do you have?

I used 82kΩ resistor.

How did you know to use an 82k resistor?

Is it based on the your old battery's thermistor value?

Great project...

I can see your phone is connected up to the power supply, How do you restart the phone when you get back to your car?

I'm having trouble with particular problem