18650 Lithium Ion Battery Capacity Tester
Intro: 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.
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.
STEP 1: What Do We Need ?
Material
- TP4056 with protection
- USB female
- USB doctor
- USB Load
- Battery holder
- Wires
- Wooden board
Lots of batteries from different sources
- TP4056 with protection
- USB female
- USB doctor
- USB Load
- Battery holder
- Wires
- Wooden board
Lots of batteries from different sources
STEP 2: Assembly
- 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
- Connect battery holder to TP4056 on +B and - B
- Connect USB to +Vout and - Vout
Check if everything is connected correctly
STEP 3: Test 1 : GTF 9800 MAh
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
Claimed Capacity : 9800 mAh
Actual capacity : 1000 mAh
Just about 10% of what it claimed
STEP 4: Test 2 : 4200 MAh
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
Claimed Capacity : 4200 mAh
Actual capacity : 500 to 600 mAh
Little above 10% of claimed capacity
STEP 5: Test 3 : Laptop Batteries LG Make
I extracted these from old HP laptop battery
Claimed Capacity : 3000 mAh
Actual capacity : 2300 mAh
Not bad for 5 year old batteries
Claimed Capacity : 3000 mAh
Actual capacity : 2300 mAh
Not bad for 5 year old batteries
STEP 6: Test 4 : Laptop Batteries Set Samsung Make
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.
Claimed Capacity : 2200 mAh
Actual capacity : 2000mAh
Not bad for 7 year old batteries
Please share your comments if you like this instructable.
10 Comments
Dumfuk 1 year ago
What did you use for the load? Please know i am very new to this. Detailed explanation would be enormously helpful and appreciated.
Paramprakash 2 months ago
He uses a USB Load to discharge the battery like this one here
https://robu.in/product/usb-mini-discharge-load-resistor-2a1a-switch-load-tester/?gad_source=1&gclid=CjwKCAiAiP2tBhBXEiwACslfnkhoiNpwgmcPnwfPV3ZtXILRVdyMfy5ED9xLgzm_k62NOR1mKK4wVhoCAukQAvD_BwE
triplej057 5 years ago
Thank you for creating this - I thought of 2 questions (and related sub-questions) that I could not answer myself.
1. How long must you test each cell for an accurate capacity reading (mAh)? Or is the capacity reading accurate instantly as soon as you power up? (because the usb tester is performing the internal math / logic and providing output display?)
2. Your USB tester appears to have a timer (mine does not) - are those times in the pictures on the USB tester display in minutes or hours?
Thank you,
Dave
Gentleheart 5 years ago
Amit_Jain 5 years ago
I let the battery connected till completly discharged. The usb doctor i used shows total time the battery was able to support and during discharge the viltage and current varies, the usb doc is able to monitor and state total capacity.
regards
Amit
darnstadium 5 years ago
The chip mentioned is also used on some phone battery packs.
I think its worth mentioning that some batteries work best if recharged before test, especially if they haven't been used for a long time (eg electric bike batteries)
For a single 18650 this is fine but larger packs may never charge due to thermal protection,
Amit_Jain 5 years ago
I will make a note of this
zomtec 6 years ago
The range of the tester is 4V - 20V.
How you test the full battery capacity from 4,2V to 2,5V?
I test the tester and the voltages is very inaccurate under 4V.
The display under 4V becomes darker.
Amit_Jain 6 years ago
my usb tester, is not rated for 20v, may be that's why, I am able to test lower voltage
zomtec 6 years ago
Where you buy it?
My Keweisi tester has a range from 4V - 20V.
All Keweisi tester i found on www.aliexpress.com has a measurement range from DC 4-20V too.