Crap, I just ordered 100 of these for an ebike battery build. I ran into the same issue with the 5 and 6amp liFePo4 cells that did not test out to capacity.
I'm still seeing about 10% low capacity cells. I'm further into the 900 I bought now, but the low capacity failure rate is not changing. If I were you, I'd test every last one of them! You'll see that some test to a reasonable capacity and others do not. IF you know what cells test low at least you can pair them up with higher capacity cells to balance out the whole pack as much as possible.
@@de-bodgery Thanks for the advise, I definetly think they are rejects from the gigafactory, no welds???? no glue???? Hope they work out, I should have several extra cells out of the 100 I ordered so hopefully it will add up to what I need for my project. Still calculating pack size and voltage but it should be a fun winter project...
@@chrishansen530 They have never been used. There's no evidence they came out of salvaged packs so the only conclusion I can make is they are part of a batch of cells that failed to pass factory testing before being used in packs. They were then sold as seconds and unscrupulous sellers like Battery Hookup lie to buyers and claim they are salvaged cells. Yeah! Suuuure they are! *** 100 cells isn't going to make a very large pack so whatever you are building, it must be at like 48v in order for you to have spares. I build almost exclusively at 82v or 20S so 100 cells would not make a very high capacity pack for me.
@@Zomby_Woof I use LIPO for what I call "build packs". I have some old Multiustar LIPO packs that I reconfigure into temp packs for whatever is my in progress current build. This gets me battery power quickly and for short term. I then build the real pack from NMC or what people commonly think of as Li-ion cells. NMC is solid chemistry with good power density and longevity. I never use LiFePO4. They are not worth it IMHO. They do have more charge cycles than NMC, but at lower charge density and more weight. It's just not a worthwhile chemistry to me for the final pack and the cell voltages don't match NMC which is the best case cell chemistry to use.
If all you care about is capacity, get several Liito Kala Lii-600's. You can't trust the cell Ir result it displays as it is egregiously wrong. They do a good job at capacity testing and not being too terribly cheaply made. If you want what I think is the best cell tester out there right new, then get the XTAR VP4+. It's much better made than the Lii-600 and it actually tests cell Ir pretty accurately. They also cost $25 more. I have 3 Lii-600 testers and 2 VP4+ testers. *** Dont get the Lii-500S they are pretty poor testers. The one I have its capacity testing is getting worse and worse despite being a couple of months old. I can't trust its results anymore. It's highly unlikely that a 4800mah cell can have 5900mah of capacity, but my Lii-500S has tested several like that. I then put those same cells in a Lii-600 or a VP4+ and I'll get a more realistic 4700-4800mah. Pretty much a waste of money!
The real model 3 Tesla cells don’t come wrapped, they also have a QR code on the side. I used them and how they come pretty much, they don’t come wrapped. I do think after watching your video and price. I have to agree and likely rejects and new. I bought used cells that were pulled and has usually the spot welds, or glue marks? Those definitely are not salvaged cells as they glue those pretty strongly and not easy to separate the cells?
Crap, I just ordered 100 of these for an ebike battery build.
I ran into the same issue with the 5 and 6amp liFePo4 cells that did not test out to capacity.
I'm still seeing about 10% low capacity cells. I'm further into the 900 I bought now, but the low capacity failure rate is not changing. If I were you, I'd test every last one of them! You'll see that some test to a reasonable capacity and others do not. IF you know what cells test low at least you can pair them up with higher capacity cells to balance out the whole pack as much as possible.
@@de-bodgery Thanks for the advise, I definetly think they are rejects from the gigafactory, no welds???? no glue????
Hope they work out, I should have several extra cells out of the 100 I ordered so hopefully it will add up to what I need for my project. Still calculating pack size and voltage but it should be a fun winter project...
@@chrishansen530 They have never been used. There's no evidence they came out of salvaged packs so the only conclusion I can make is they are part of a batch of cells that failed to pass factory testing before being used in packs. They were then sold as seconds and unscrupulous sellers like Battery Hookup lie to buyers and claim they are salvaged cells. Yeah! Suuuure they are!
***
100 cells isn't going to make a very large pack so whatever you are building, it must be at like 48v in order for you to have spares. I build almost exclusively at 82v or 20S so 100 cells would not make a very high capacity pack for me.
@@de-bodgery Are yiu using li-ion/li-po exclusively?
@@Zomby_Woof I use LIPO for what I call "build packs". I have some old Multiustar LIPO packs that I reconfigure into temp packs for whatever is my in progress current build. This gets me battery power quickly and for short term. I then build the real pack from NMC or what people commonly think of as Li-ion cells. NMC is solid chemistry with good power density and longevity. I never use LiFePO4. They are not worth it IMHO. They do have more charge cycles than NMC, but at lower charge density and more weight. It's just not a worthwhile chemistry to me for the final pack and the cell voltages don't match NMC which is the best case cell chemistry to use.
What tester would you recommend?
If all you care about is capacity, get several Liito Kala Lii-600's. You can't trust the cell Ir result it displays as it is egregiously wrong. They do a good job at capacity testing and not being too terribly cheaply made. If you want what I think is the best cell tester out there right new, then get the XTAR VP4+. It's much better made than the Lii-600 and it actually tests cell Ir pretty accurately. They also cost $25 more. I have 3 Lii-600 testers and 2 VP4+ testers.
***
Dont get the Lii-500S they are pretty poor testers. The one I have its capacity testing is getting worse and worse despite being a couple of months old. I can't trust its results anymore. It's highly unlikely that a 4800mah cell can have 5900mah of capacity, but my Lii-500S has tested several like that. I then put those same cells in a Lii-600 or a VP4+ and I'll get a more realistic 4700-4800mah. Pretty much a waste of money!
The real model 3 Tesla cells don’t come wrapped, they also have a QR code on the side. I used them and how they come pretty much, they don’t come wrapped.
I do think after watching your video and price. I have to agree and likely rejects and new. I bought used cells that were pulled and has usually the spot welds, or glue marks? Those definitely are not salvaged cells as they glue those pretty strongly and not easy to separate the cells?
Yeah...seconds for sure!