Help with mAh

[b0re]

Hello,

New here.

I have 600 ofCGR18650CG (2250mAh Rated) I charged 200 of them and left them for 2-3 weeks, I then did a voltage test and got 4.18v on average happy with that. I then ran a discharge test on 50 getting 2456mAh on average the link says 2250mAh Rated?

After my discharge,im left with 3.2v im using an Opus BT-C3100.

Did I miss somethinghere?

 

[Korishan]

What was your discharge rate? The datasheet uses a discharge current of 430mA, and down to 3.0V.

It is possible you got a "good" batch that is yielding higher values than the datasheet is spec'd for.

OOoorrrrr......

Your tester isn't calibrated properly. Hopefully you don't have a fake Opus unit. Do you have another unit to compare the values with?

 

[daromer]

Opus Always show higher. Around 10% above so ur Numbers are normal.

 

[b0re]

The od bit is once charged they were tested with a volt tester at 4.2v after discharge showing 3.15v was expecting 3.0v

I discharged at 1000mA. I will run a test at 500mA and see if I get the same results.

 

[Korishan]

3.15V is fine. That means there was bounce back, or recovery as others put it. All cells will recover a certain amount after the load is disconnected. This is normal and healthy. It's the ones that "don't" recover are the ones you worry about.

 

[daromer]

Normal. Opus discharge to 2.8V and then they bounce back. The higher current you test with the higher bounce back you get.
The better cell the less bounce back you will back in generall you could say.

Korishan: your bounce back theory is wrong. The ones that bounce back more have higher IR and is in worse shape. Less bounce back = more utilization of the cell = better cell.


Bounce back of up to 3.3 or even 3.5 on high current is normal... The cells are considered empty at that voltage or close to empty