Wolf,
You are going to have a pw based on IR, oke mine is also(+ soh%, min 90%).
Thanks to you i weed out some bad and ugly ones :exclamation:
Well actually my testing of cells is based on IR the Power Wall is just the recipient of a good harvesting strategy.
But there are cells that are testing around 70mohm at average.
I have around 800 pcs of one kind: the only ones i keep are between 63and 77mohm
Yes there are some cells esp theLGAAS31865,LGDAS31865, andLGEAS31865 never mind the Sony US18650GR G* series
that perform good all the way to 80m? and above. As most of my cells average around 50m? I decided to make my cut off75m?.
The same for cells that are testing around 30 mohm.
I keep only 25 to 35 mohm
Those numbers are also around the 1000.
The cells that are <30m? are more than likely high drain cells such as those found in powertools. Mostly INR chemistry cells.
I keep those separate as they will make a great high drain battery for lots of power in a short period of time.
So al thosenumbers are in your borders, but a cell that has a good average at 30 mohm is alsogood at 70 mohm?
Or the other way around?
Or i missing a point somewhere and i wasthrowing away to many cells?
I think you will find that the low m? cells are INR or IMR chemistry the added manganese and or nickle in the chemistry make them very low IR and high drain.
I have some brand new INR18650-25R cells with an IR of 13m? to 14m?. I have gottensome from power toolpacks andonce their IR goes over 25m? they die and are generally SD cells. But just because a cell has low IR does not mean its bad its just a different chemistry.
Those are the most extreme, from 25 to 77mohm
i keep the onesbelow 20 and above 77separate.
If there aremore than 100 cells of each spec (below 20 or above 77)and testing good in soh(more than 90%), i will make a test wall(brick/pebble wall) with it.
Exactly the low IR ones you can use especially if they test goodand build a nice ~12V battery with them.
The high IR ones you can build a great backup battery to some led lighting that doesn't need gobs of power.
Lets see what happens to them or you got a clue? because i don't have one about them.
Will test them in a separate system with some peltier elements.
See above
I test per manufacture and the same type of cell, if i have below 100 cells per manufacturer and same type, the wont be in my powerwall, first a steady average IR test.
Why per 100, only unknown IRcells to get a known IR.
That is why I have my database and it can be searched by all type of cells that I have processed. Its up to 6058 recorded cells now.
And that's how I built the IR by part number sheet to guide my what is an acceptable IR for each cell manufacturer and part number.
Thanks and best.