Suggestions on "new" ebay cells

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BGrillo

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Nov 11, 2017
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Hello this is one of my first posts, been a lurker for a while. I bought the LG cells from AlarmHookup and have disassembled almost 100 packs over the last week. I have a 20 place tp4065 charger and 4 opus'. My initial plan was to charge each cell fully and discharge at 1a for an hour (for better "storage")and set them aside to make packs over the next month or so.

Some of the voltages are already at 4.2v, and a few are at just over 1v. I have been marking the low ones and I am wondering if I should do a full test / discharge test on them with the opus. Is this necessary? Should I be doing something completely different with all the cells??

Thank you.
 
It serves no purpose to charge and then discharge the cells a bit to "store" them. Instead you can focus on the low voltage cells. Separate all cells into two groups, over 2.5V and under 2.5V. The cells are new so the normal cells will have their specified capacity. The low voltage cells need to be charged and tested as they might have suffered some kind of damage.
 
I personally would test all cells, regardless of voltage. Unless they are truly 0V and/or internally shorted. Even if they are "new" cells, they'd get capacity tested. IMHO
 
Fair enough, you could do this. I used to do this myself and it will certainly do no harm. Personally I've stopped doing this now because new cells will produce consistent results. If I have no doubts about the new cells I get then I don't do it.
 
I just run the test. Ie charge/discharge/charge. Get capacity and let them sit for acouple of weeks to check disacharge then I build the packs. No use making it more complicated.
 
Thank you DarkRaven, Korishan, daromer and mike! I will test all the cells and then retest before I put the packs together for self discharge. I will update this thread when I am finished with any interesting findings. I hope 98% are good or I will need to rethink my pack layout. I ran the ~1v cells and they tested fine so I think I will be ok.
 
BGrillo said:
Thank you DarkRaven, Korishan, daromer and mike! I will test all the cells and then retest before I put the packs together for self discharge. I will update this thread when I am finished with any interesting findings. I hope 98% are good or I will need to rethink my pack layout. I ran the ~1v cells and they tested fine so I think I will be ok.
Click to expand...

Just curious, how many of those 1v cells did you encounter? I also have these packs and I've not encountered a bad batch yet, but I did not check for voltage prior to the initial charge, only after.
 
not2bme said:
BGrillo said:
Thank you DarkRaven, Korishan, daromer and mike! I will test all the cells and then retest before I put the packs together for self discharge. I will update this thread when I am finished with any interesting findings. I hope 98% are good or I will need to rethink my pack layout. I ran the ~1v cells and they tested fine so I think I will be ok.
Click to expand...

Just curious, how many of those 1v cells did you encounter? I also have these packs and I've not encountered a bad batch yet, but I did not check for voltage prior to the initial charge, only after.
Click to expand...

Ha - not many so far, maybe 6? It may have been a bad pack, I am not sure what would have happened. They charged and capacity tested fine, and are sitting waiting for a discharge check.

I have had some cells come close to 2000 mah, where they are stated as being 2200. I have also had some around 2400 too, and I suspect the average will be 2250 to 2300 for all the cells tested on the opus.

Damaged cells are in here too. Not terrible but I have had a handful of cells that were clearly dropped at one point. I said something about it and Alarm Hookup sent me another pack to replace them. I bought the LG batteries (100) packs and had 3 packs that had samsung batteries and 4 that were an unknown brand. I returned the unknowns and am awaiting 4 LG packs to replace them. So, not perfect but not terrible yet.
 
BGrillo said:
not2bme said:
BGrillo said:
Thank you DarkRaven, Korishan, daromer and mike! I will test all the cells and then retest before I put the packs together for self discharge. I will update this thread when I am finished with any interesting findings. I hope 98% are good or I will need to rethink my pack layout. I ran the ~1v cells and they tested fine so I think I will be ok.
Click to expand...

Just curious, how many of those 1v cells did you encounter? I also have these packs and I've not encountered a bad batch yet, but I did not check for voltage prior to the initial charge, only after.
Click to expand...

Ha - not many so far, maybe 6? It may have been a bad pack, I am not sure what would have happened. They charged and capacity tested fine, and are sitting waiting for a discharge check.

I have had some cells come close to 2000 mah, where they are stated as being 2200. I have also had some around 2400 too, and I suspect the average will be 2250 to 2300 for all the cells tested on the opus.

Damaged cells are in here too. Not terrible but I have had a handful of cells that were clearly dropped at one point. I said something about it and Alarm Hookup sent me another pack to replace them. I bought the LG batteries (100) packs and had 3 packs that had samsung batteries and 4 that were an unknown brand. I returned the unknowns and am awaiting 4 LG packs to replace them. So, not perfect but not terrible yet.
Click to expand...

I never bothered with anything below 1V before but after reading here I now try down below .5V regularly.
The recovery rate is pretty low for me, maybe 15-20% if that but if you find cells are scarce and hard to come by like I do its a way of getting a few more good cells from your stock.

Jimmy
 
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