Bought some BIG (280AH) cells on Alibaba

[Maast]

Great!
Did it occur to include Sinopoly cells in the tests?
Found Winston and CALB, reputable suppliers of these as mentioned on one of the sites.
Then there are samsung NCM cells (Nickel-cobalt-manganese) at a slight premium.
Since these are standard suppliers, may be its worth considering especially if eventually a lot of money is on the stake.

I'm myself looking into a similar project, but a portable one.

If somebody wants to send me one I'd be happy to test it, but I already dropped 200 bucks or so on each cell including shipping and I jsut spent another 140 bucks on a 120A constant current power supply and I don't really want to drop any more.

 

[Bhupinder]

If somebody wants to send me one I'd be happy to test it, but I already dropped 200 bucks or so on each cell including shipping and I jsut spent another 140 bucks on a 120A constant current power supply and I don't really want to drop any more.

Absolutely agree with the status-quo.
Will mentions highly about these sinopoly cells, may be he can arrange test prototypes from sponsors/ promoters.
General public would then get to see the true and clear picture for once.

BR

 

[Michael B Caro]

Hi Amy, there may be other manufacturers for you to obtain cells from. A year ago I started testing 280AH cells from various manufacturers. I very much liked two of them. One were cells with GFB277 on the label, and the other was a ETC cell. They both tested above 280AH. I had three GFB277 cells from different vendors and they all tested above 280AH.
The ETC cell looks identical to the EVE cells that are so popular.
Here is a link to the thread of my original testing: https://diysolarforum.com/threads/bought-some-big-280ah-cells-on-alibaba.1234/

Never heard of the GFB277, but I have been offered the ETC brand by a couple of suppliers at a price point in between Lishen and Eve. I have not done anything with the ETC brand as I was not aware of anyone in the US having used or tested them. I am glad to see that they tested well for you and will now take a closer look at handling them.

 

[Gazoo]

One were cells with GFB277

I haven't been able to find the manufacturer...have you? I thought it might be Ganfeng but not sure.

 

[Dzl]

I haven't been able to find the manufacturer...have you? I thought it might be Ganfeng but not sure.

I believe GFB is "GanFeng Battery" (aka Ganfeng)
A subsidiary of "Ganfeng Lithium Co. Ltd. (GFL or Ganfeng)" which seems to be a big multinational higher up the food chain (lithium extraction, and processing)

I am not positive, but based on the datasheet I have, which is titled GFB_100Ah_[...] it seems likely that these would be the same company.

 

[Stever73]

I‘ve found Ganfeng too, seems a very large company that sells batteries to Tesla also. http://www.ganfenglithium.com/index_en.html

 

[Zwy]

Sorry for the delay, now that it's winter and cold and I had the shop door closed I got concerned at the sheer amount of outgassing from the liquid rheostat so I tore it apart and am replacing the load with loops of .032 stainless steel safety wire in the 30 gallon drum. FYI at 3.4 volts one 16 inch strand is a 5 amp load.
I'm also rebuilding the tester to automate life cycle testing. At first I was going to use a arduino but that was a heavy slog so now I'm using time delay relays and I think I like those a lot better. I've got my worst battery under test now w/ a 60 amp load (.2C ish) so I can take a picture of the readout. Should be done here in a few hours and I'll post it.

Stainless steel could give you chromium contamination in you solution. This is nasty stuff. Now, if you're just running the giant resistor dry, well, have at it.

It's the reason I use carbon rods for rust removal using electrolysis.

 

[Zwy]

Here is my first result, thats my worst battery and even that one put out 279AH going from 3.65V all the way down to 2.5V at .2C (ish)
I dont like that cell mainly because its voltage droops .075V under even a mild 20 amp load. Also a pic of my semi torn-apart tester my cc power supply and my mickey-mouse load bank.

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Please stop, the Chromium 6 will kill you. https://en.wikipedia.org/wiki/Hexavalent_chromium