Lithium Battery Capacity Tester

Introduction: Lithium Battery Capacity Tester

About: Hi my name is Steve and i'm a Creative and I got Technical skills i can build anything just stick to my account . I'm a YouTuber so you also can see my all videos here

Hey! everyone My name is Steve .

Today i'm going to show you How to Test Lithium Battery Capacity .

Couple of weeks back i took 18650 Battery from an Old Laptop Battery

I don't know the current Capacity of these batteries So i did this test to find out how much capacity is left

Click Here to See The Video

Let's Start

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Step 1: Stuff I Used

  • Lithium Battery Capacity Tester click
  • 18650 Lithium Battery (Test Subject)

Lithium Battery Capacity Tester

  • It's Supplyed with 2 7.5 ohms 5W resistance
  • it can take input up to 15V and 3 Amps


  • Fully adjustable according to your need
  • very cheep price

Step 2: Connection

You can see the label over the board

+ Connects to Battery positive

- Connects to Battery negative

R Connects to Resistance (Load )

R Connects to Resistance (Load )

You need a wall adapter or a power bank to power the Module

Step 3: Attention !

Make Sure Your Test Battery are Fully Charged

*Otherwise the result will be less then what it is capable up to

Step 4: Configuration

All things are connected Now you are good to go

  • you can see "-" and "+" button are there you can set the cut off voltage from there (For example - Lithium battery the cut off voltage will be 3v )
  • Now hit "Ok" button to start the test

It will take 2-3 hours to test (time is depending upon the batteries )

Step 5: Result

After 3 hours of test i got 1246mAh of capacity left in my old 18650 battery

Happy to see that

Thank you for visiting my Instructables

1 Person Made This Project!


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2 Discussions


11 months ago

Hi, I got the same battery capacity tester. If I use both ceramic resistor, instead of 1 like on your picture, what do you think??
Or use another ceramic Resistance, with higher rate??

hemavathi sugumar
hemavathi sugumar

Question 1 year ago on Step 5

Can I get gerber file of li-ion battery capacity tester pcb poard