Dr.Dickie said:

Hey guys, glad I found this forum.

I am in the process of testing the capacity of a bit over 1000 LGM26 cells. I had an Opus tester for about 6 months, and just recently got another (I have 2 MegaCellChargers coming this month--I CAN"T WAIT).......................... If a difference of about 0.050 Ah capacity difference not worth worrying about?--about what I think the new Opus gives compared to the old one.

Thanks for any opinion

@Dr.Dickie

You have what I have come to realize as accuracy fatigue.

Let me explain. We all are looking for the perfect mAh results that are consistent every time over and over again. That is not possible due to many reasons. In a perfect world you put a cell in a charger/tester and you get "2590mAh" results and you do it again and you get "2590mAh" results. Unfortunately this does not happen. One time we get 2655mAh then we get 2595mAh and we get on the 3rd try 2602mAhso we are always left to wonder what is the true mAh of the cell.

I have just recently tested 1600 LGM26 cells and if they are coming from the same source as I think they are you are going to be all right.

The only stipulation that i make on that is to make sure you check the IR (1kHz 4 wire AC) and if your cells are in the 35m? to 39m? range they will be good.

I used 10 chargers/testers in my analysys. 1 Vapecell, 1 SKYRC, 3 Opus, 1 XTAR, and 4 Foxnovo.

The results of theses chargers varied ?5%

And averaging out all the cells by tester resulted in this data.

It obviously shows that at least myOPUS chargers on average report higher than standard results.

So what to do? To be honest nothing. In my case after choosing the lowest IR and best SOH cells out of the 1600 I came up with ?1200 cells from all various chargers.

I ran them through an excel repacker that takes the cells and sorts them into packs by cell # and mAh results. The way this works it takes the highest values first and then distributes all these cells evenly into packs. In the final analysis 100mAhor even 200mAh won't make a big difference since the inaccuracy of the testers will be absorbed into the pack.

After running my 1200 cells for my 14s80p pack the required 1120 cells here extrapolated and I built the packs accorningly. Testing the 14 packs proved to be a success as the difference between the min and max packwas 2.11Ah.

So Using 10 chargers of various makes and models in the final analysis didn't make that much of a difference in the whole outcome. Of course using only 1 brand of cell and all the same capacity makes a huge difference. My first pack which was a frankenstein pack had similar results but all cells were very carefully chosen.

I also have 2 Megacell chargers and Have done a test on them seehttps://secondlifestorage.com/showthread.php?tid=9855&pid=68372#pid68372

No need to post it twice.

Have fun

Wolf