Some day in February I've ordered 16 cells from Alibaba/Exliporc @107 USD plus shipping from EU warehouse. I was promised brand new, grade A cells.
As I was away for work, I asked the seller to postpone the shipping as much as possible.
So, today I unpacked the cells and made a quick check on them. They where packed in the same heavy thick foam like other have already pictured. It came with just a little surface damage on one pack of four, others where pristine.
They have no bulging visible, on many the shorter side is visible concave, possible to see that on the group shot. If there is bulging, it disappears with a slightest pressure of my hand.
For each cell I've checked the voltages/IR and wrote down the serial numbers, then decoded the manufacture date.
Here's the group shot.
Behind them are two Kunkin KP184 electronic loads, together with the third one I have in the lab they'll provide 120A (0.43C) discharge current (almost the rated 0.5). Unfortunately, my high power supply is not yet delivered (3.3V 150A) so no charging for me I won't even try to charge with 5/10A lab supplies I have. It will take forever, and I have no time for that. I have a 48V/50A PSU, but I don't want to charge them in group, I want to see each one's capacity.
On the right, the pink stuff is silicone baking mat, will use it as cell separator. It's soft, flexible, electrically insulating, rated up to 200°C and it's food grade
You may noticed that cell C-011 is bolded in the table above. It's because I found something strange on the venting valve, and I'm not sure how to react. It's probably the reason for "reject" and it's probably only cosmetic, but I'm not sure yet.
If you zoom in, in the right top corner of the valve is a hole that is not supposed to be there. Tomorrow I'll may try to make a better image and check again.
Coming next: Custom frame for the cells, with spring preload.
As I was away for work, I asked the seller to postpone the shipping as much as possible.
So, today I unpacked the cells and made a quick check on them. They where packed in the same heavy thick foam like other have already pictured. It came with just a little surface damage on one pack of four, others where pristine.
They have no bulging visible, on many the shorter side is visible concave, possible to see that on the group shot. If there is bulging, it disappears with a slightest pressure of my hand.
Cell # | Serial # | Date of mfgr | Voltage (V) | IR (mΩ) |
C-001 | 04QCB76717600JB4S0001234 | 25/Apr/2021 | 3,2939 | 0,20 |
C-002 | 04QCB76716300JB5Y0004939 | 30/May/2021 | 3,2937 | 0,20 |
C-003 | 04QCB76717600JB4S0003292 | 25/Apr/2021 | 3,2938 | 0,20 |
C-004 | 04QCB76717600JB4S0001998 | 25/Apr/2021 | 3,2928 | 0,22 |
C-005 | 04QCB76717100JB5H0005494 | 17/May/2021 | 3,2927 | 0,22 |
C-006 | 04QCB76717100JB5H0005448 | 17/May/2021 | 3,2934 | 0,20 |
C-007 | 04QCB76716000JB5V0005505 | 27/May/2021 | 3,2894 | 0,22 |
C-008 | 04QCB76717900JB5S0004603 | 25/May/2021 | 3,2847 | 0,19 |
C-009 | 04QCB76715000JB4N0002018 | 22/Apr/2021 | 3,2939 | 0,21 |
C-010 | 04QCB76715000JB4N0001276 | 22/Apr/2021 | 3,2938 | 0,21 |
C-011 | 04QCB76716000JB5V0004986 | 27/May/2021 | 3,2078 | 0,21 |
C-012 | 04QCB76716100JB5V0000444 | 27/May/2021 | 3,2917 | 0,21 |
C-013 | 04QCB76715000JB4N0001086 | 22/Apr/2021 | 3,2939 | 0,21 |
C-014 | 04QCB76717900JB5S0004050 | 25/May/2021 | 3,2920 | 0,20 |
C-015 | 04QCB76717500JB4R0001867 | 24/Apr/2021 | 3,2939 | 0,20 |
C-016 | 04QCB76717500JB4S0005394 | 25/Apr/2021 | 3,2940 | 0,19 |
For each cell I've checked the voltages/IR and wrote down the serial numbers, then decoded the manufacture date.
Here's the group shot.
Behind them are two Kunkin KP184 electronic loads, together with the third one I have in the lab they'll provide 120A (0.43C) discharge current (almost the rated 0.5). Unfortunately, my high power supply is not yet delivered (3.3V 150A) so no charging for me I won't even try to charge with 5/10A lab supplies I have. It will take forever, and I have no time for that. I have a 48V/50A PSU, but I don't want to charge them in group, I want to see each one's capacity.
On the right, the pink stuff is silicone baking mat, will use it as cell separator. It's soft, flexible, electrically insulating, rated up to 200°C and it's food grade
You may noticed that cell C-011 is bolded in the table above. It's because I found something strange on the venting valve, and I'm not sure how to react. It's probably the reason for "reject" and it's probably only cosmetic, but I'm not sure yet.
If you zoom in, in the right top corner of the valve is a hole that is not supposed to be there. Tomorrow I'll may try to make a better image and check again.
Coming next: Custom frame for the cells, with spring preload.
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