18650 Lithium Ion Battery Capacity Tester

Hi All,

I had bought few 9800 and few 4200 mAh lithium ion batteries from Aliexpress last year.

They were quite cheap... and as I researched more on them, I found that these are fake and their actual capacity may be very less.

Then I extracted Lithium ion batteries from old laptop battery. But wondered are these still at original capacity or have reduced their capacity

For a beginner DIYer it is difficult to buy expensive testers....

So, in this instructable, I will share how to make 1s lithium ion battery capacity tester

Please share your comments if you like this instructable.

Material
- TP4056 with protection
- USB female
- USB doctor
- USB Load
- Battery holder
- Wires
- Wooden board

Lots of batteries from different sources

- Using hotglue, glue battery holder and TP4056 module
- Connect battery holder to TP4056 on +B and - B
- Connect USB to +Vout and - Vout

Check if everything is connected correctly

I had got 4 batteries for 6 dollars. It claimed to have 9800mAH

Claimed Capacity : 9800 mAh
Actual capacity : 1000 mAh

Just about 10% of what it claimed

I had got 4 batteries for 3.5 dollars. It claimed to have 4200mAH

Claimed Capacity : 4200 mAh
Actual capacity : 500 to 600 mAh

Little above 10% of claimed capacity

I extracted these from old HP laptop battery

Claimed Capacity : 3000 mAh
Actual capacity : 2300 mAh

Not bad for 5 year old batteries

I extracted these from old HP laptop battery

Claimed Capacity : 2200 mAh
Actual capacity : 2000mAh

Not bad for 7 year old batteries


Please share your comments if you like this instructable.