Here we go again ? ?
Why are there so many Grade B cells? Is anyone here able to comment on the manufacturing process of LTO?
What is the approx cost per Ah or cost per kWh for these suppliers. How does it compare to the others.This is why I developed a system to test every cell before I sell them on ebay. Grade A is Chinese for they look pretty. After testing over 1000 cells I have found 2 suppliers that actually sell full capacity cells as advertised
the price is all within a few dollars per 45 Ah cell. It is just a matter of finding suppliers who have the good goods.What is the approx cost per Ah or cost per kWh for these suppliers. How does it compare to the others.
If they are all used .... seems like they should be able to sell them a lot cheaper than they are. Maybe they figure they have such longevity that they can get away with it.Interesting if it is true those cell are used like all hell. But still are usable for us.
Isn't that the truth. I guess it is possible that these cells or any of the cells could be used but still look new. They could be protected in an enclosure and never touched for years.If they are all used .... seems like they should be able to sell them a lot cheaper than they are. Maybe they figure they have such longevity that they can get away with it.
I think suspicion/skepticism is a good default approach in this context. When I first joined the forum this was the norm, and due diligence and skepticism was passed on to new folks like myself. But over time that spirit has been watered down more and more, most notably with the explosion of new users joining to get in on the cheap EVE cells.These ideas have made me more suspicious of all of the cells including the EVE cells we all are using. Most of the terminals on the cells we get have marks on them. But any cell manufacturer would be sure those terminals were protected.
This has convinced me that we are buying used cells. China's revenge for Cash for Clunkers
Usually the bad ones have a low voltage when I pull them out of the box for testing this is not a completely accurate test though but about 80% effective. Yes I think all of these cells are used but still have plenty of life left for solar. I have my home setup going now for about 5 months without even looking at it. This runs my garage only and a chest freezer not the whole house. My Idaho cabin setup has been going since April without issue as well.If they are all used .... seems like they should be able to sell them a lot cheaper than they are. Maybe they figure they have such longevity that they can get away with it.
@Craig .... What is your experience with the IR on these cells? Can you tell from an IR check how they are going to perform?
Yes I think all of these cells are used but still have plenty of life left for solar.
I am not convinced the EVE's are used. Where would that many used EVE cells come from? I would think thousands have been sold. Also used cells usually have the label scratched off or altered. And even the ones that have tested at 265ah's have 95% capacity. It seems kinda strange to me we bought used cells. But I don't know any more than you do about where these cells are actually coming from. I suspect they are simply factory rejects good enough to sell on the grey market. All of mine have been marked with a black magic marker....whatever that means.66% left if you believe the picture. I'm not sure what to believe.
For my purposes it probably won't make any difference but I doubt you can expect to get 10 years of heavy use out of used EVEs.
What makes you trust OSN or Kokpower? Or maybe a better question, how did you first come to trust them before you had experience with them?Will : Granted you probably got 35ah re wrapped cells , But I thought AH tests should be done at 1C.
The doubling up on the buss bars isn't a good idea , Because of aluminum anodizing is an oxide and adds to the resistance , Its better to use a one thicker bar.
Also I do not trust anybody Aliexpress , They are like an Ebay, I use Alibaba with Osn and Kokpower , I have received what I ordered to spects.