I have purchased a few HW586 testers and over the last few days I have done some testing of a tester.
I am a bit disappointed with the results.
First a bit about the testing:
I used a single Sanyo cell (red wrapper, green ring)
I used the same HW586 tester, with 1 resistor, set to test down to 3 volts. I thought that 1 resistor might stress the cell less, and give more consistent results.
I used the same TP4056 charger
I tested voltage of the cell before the test and after the test. The time when the test finished until when the voltage was checked varied. I am not sure if the voltage may have bounced back more when longer times between testing finishing and voltage checking was completed.
The test was done in an undercover area outside in Sydney. Temperatures varied a fair bit between daytime and nght time. Charging and testing was done whenever I saw that the last step was complete, so some charging/tests were at night and some in the daytime.
Here are the results
Test Start Voltage Capacity End voltage
1 4.21 2752 3.55
2 4.23 2965 3.48
3 4.20 3029 3.48
4 4.20 2985 3.46
5 4.21 3058 3.43
6 4.22 2860 3.58
7 4.22 2890 3.59
8 4.17 2809 3.51
9 4.20 2937 3.52
10 4.23 2912 3.59
Highest result: 3058
Lowest result: 2752
Difference : 306
From looking the the cell database I think the cell is a UR18650FK which was originally rated at 2100mAh, so the results are already way too high. The high numbers would not worry me too much as long as the results were repeatable, then the sorting of cells would still be ok.
From memory, I think Pete (hbpowerwall) did some repeated testing of cells and the results also looked a bit inconsistent, but I dont think it was as much as above.
I am not happy that my testing could be this inconsistent. My plan to follow others process of binning in 100mah increments looks pointless if the testing results are so variable.
Is day vs night temperature going to make a difference (or that much difference) to the test results?
Is this amount of inconsistency normal in testers?
Is the hw586 I used no good?
Are hw586 testers in general no good?
Can anyone shed some light on this?
I am a bit disappointed with the results.
First a bit about the testing:
I used a single Sanyo cell (red wrapper, green ring)
I used the same HW586 tester, with 1 resistor, set to test down to 3 volts. I thought that 1 resistor might stress the cell less, and give more consistent results.
I used the same TP4056 charger
I tested voltage of the cell before the test and after the test. The time when the test finished until when the voltage was checked varied. I am not sure if the voltage may have bounced back more when longer times between testing finishing and voltage checking was completed.
The test was done in an undercover area outside in Sydney. Temperatures varied a fair bit between daytime and nght time. Charging and testing was done whenever I saw that the last step was complete, so some charging/tests were at night and some in the daytime.
Here are the results
Test Start Voltage Capacity End voltage
1 4.21 2752 3.55
2 4.23 2965 3.48
3 4.20 3029 3.48
4 4.20 2985 3.46
5 4.21 3058 3.43
6 4.22 2860 3.58
7 4.22 2890 3.59
8 4.17 2809 3.51
9 4.20 2937 3.52
10 4.23 2912 3.59
Highest result: 3058
Lowest result: 2752
Difference : 306
From looking the the cell database I think the cell is a UR18650FK which was originally rated at 2100mAh, so the results are already way too high. The high numbers would not worry me too much as long as the results were repeatable, then the sorting of cells would still be ok.
From memory, I think Pete (hbpowerwall) did some repeated testing of cells and the results also looked a bit inconsistent, but I dont think it was as much as above.
I am not happy that my testing could be this inconsistent. My plan to follow others process of binning in 100mah increments looks pointless if the testing results are so variable.
Is day vs night temperature going to make a difference (or that much difference) to the test results?
Is this amount of inconsistency normal in testers?
Is the hw586 I used no good?
Are hw586 testers in general no good?
Can anyone shed some light on this?