Battery Charger + Capacity (mAh) Tester




About: Ideas Into Reality !

Let's Make 3.7v Lithium Battery Charger That Tests Battery Capacity in mAh Using TP4056 And Usb Power Monitor Usb 5v Input Makes it Versetile to use it Any where on the go !

Watch the video

Tp4056 is Perfect Lithium Battery Charger And Usb Power Monitor Gives You Your Battery's Remaining Storage Capacity (mAh) So you will always know your battery parameters and how good your battery is !

With This Battery Charger + Capacity Tester You can Actually Measure and Compare Battery Capacity With Standard values (mAh).

Step 1: You Will Need

1. TP4056 Battery charging Module (0.75$)

2. Battery Charging Case (3$)

Your Case May Vary

3. 3.7V Battery

4. USB Power Monitor OLED Display(5.53$)

Similar But Cheaper Lcd one (3.34$)

Step 2: Just Plug It In!

1.Connect TP4056 Board to Battery Case and slide in the battery you want to Charge and test

2. Now Attach a USB Power Monitor between your battery charger and USB Power Supply.

3. Make sure to discharge the battery fully before test.

Step 3: Let's Measure MAh

1. You Should able to see your batter Capacity counting up as the battery charges.

2. Also the red Led of TP4056 glows when battery is being charged.

3. Once battery is fully charged Green Led will turn on and charging is stopped ,and bingo Now you can see the battery Capacity on the Power Monitor.

Step 4: Fake 6000 MAh Battery Spotted!!!

Well to test some I ordered Ultrafire 6000 mAh Battery From eBay!
and gues what ,its only 600 mAh!!!

I think they've misplaced a zero at back,lol...

Hope this helped you ,hmm... What Do You Think?

Check Out My Other Instructables, you might like this electric screwdriver !



    • Arduino Contest 2019

      Arduino Contest 2019
    • Tape Contest

      Tape Contest
    • Trash to Treasure

      Trash to Treasure

    11 Discussions


    2 years ago

    18650 batteries never can be more than 2700mAh!

    i have some Panasonic Cells that named 8800mAh!

    3 replies

    Reply 1 year ago

    they can, it just depends what brand. For example, you can never go wrong with Nitecore.


    Reply 1 year ago

    Nitecore batteries are longer than the standard 18650. They don't fit in some of my electronics. The capacity is good, but it's cheating to compare them to other 18650s.


    Reply 1 year ago

    That's because Nitecore (and other bands) batteries come with a protection circuit built in. He battery itself isn't longer, it's just the added protection. These brands buy Panasonic batteries (I think), add protection, and shrink wrap them.


    3 years ago

    Dont forget, that it will not be the most accurate device, since the tp4056 module will convert some of the power consumed to heat. To make this more accurate you must find out the amount of power lost in the proccess...

    1 reply

    1 year ago

    amazing project, just read it, 10 seconds later ordered the parts to make it.


    3 years ago

    Really interesting. I add it to favorites to read it again later.

    Nice project!