Xuba Electronics: DEAL - 280AH LiFePo4 cells. Purchase & Review

[JoeHam]

Probably not, my is Visa

The common denominator seems to be Capital One. They issue MC and VISA cards.

 

[hankcurt]

Steve, I read through the EVE LF280 Spec Sheet that you posted on Thursday, and there is one part of it where I just don't understand what they are talking about. In the table portion, they have this information on cycle life:


I think there is a misprint, and one is supposed to be (Without fixture) and the other (With Fixture), but the cycle life difference is significant. It seems they are talking about the clamping pressure the cells are under, but I'm just guessing. 300kgf seems like a lot of pressure.

Later in the same specification document, in the graphs and charts section, they have this page:



Once again talking about with or without 'Fixture'. I'm guessing that perhaps the black line is actual test data and the red is projected life? Anyway, they show that with fixture initially drops in capacity more quickly, but then takes 1500 more cycles to get down to 80% capacity. Does anyone have any idea what a 'Fixture' is or how they intend 300kcf of force to be applied to the cell? The google machine has been of little help so far in trying to answer this question.

 

[DW SD]

My 280Ah LFP cells arrived today! Right on schedule... per Amy's 10 day ETA.
Yesterday, there was no tracking update except pending. Then this morning I received a text from Fedex that they were out for delivery. And then a new text that they were delivered!
I opened the package. The cells were very well packed, two nested heavy cardboard boxes with thick foam wrapping each individual cell. A+ for packing.
I tested voltage with my Fluke. All 4 tested @ 3.290 V.
Came with M6 terminal bolts and large pack of busbars. I might swap the terminal bolts for stainless vs. mild steel with yellow zinc coating. We'll see.
Very happy so far!

Doug

 

[Steve_S]

NOTE regarding Amy @ Xuba. I sent her a note on the BUMP issue as I rechecked the photo's with heavy zoom of the cells they are sending me, it appears that possibly 4 have that similar bump. Now it's 01:00 or so there now, so I do not expect an answer back for a bit.

@DW SD \\WOOHOO// Doug, I know what your doing today LMAO... me, more snowblowing … ugh...

 

[Steve_S]

Steve, I read through the EVE LF280 Spec Sheet that you posted on Thursday, and there is one part of it where I just don't understand what they are talking about. In the table portion, they have this information on cycle life:
---
I think there is a misprint, and one is supposed to be (Without fixture) and the other (With Fixture), but the cycle life difference is significant. It seems they are talking about the clamping pressure the cells are under, but I'm just guessing. 300kgf seems like a lot of pressure.
---
Later in the same specification document, in the graphs and charts section, they have this page:
---
Once again talking about with or without 'Fixture'. I'm guessing that perhaps the black line is actual test data and the red is projected life? Anyway, they show that with fixture initially drops in capacity more quickly, but then takes 1500 more cycles to get down to 80% capacity. Does anyone have any idea what a 'Fixture' is or how they intend 300kcf of force to be applied to the cell? The google machine has been of little help so far in trying to answer this question.

My Chinglish Translator can't manage everything. I find some of the stuff a bit erroneous because It is so poorly translated. You would think they would have English Speakers, Reader's / Writers at least verify the translation to make sure it makes sense. I just pass along the info as was provided, I am JUST A CUSTOMER sharing info, details to try and help fellow Solar Adventurers.

 

[Sgt Raven]

My 280Ah LFP cells arrived today! Right on schedule... per Amy's 10 day ETA.
Yesterday, there was no tracking update except pending. Then this morning I received a text from Fedex that they were out for delivery. And then a new text that they were delivered!
I opened the package. The cells were very well packed, two nested heavy cardboard boxes with thick foam wrapping each individual cell. A+ for packing.
I tested voltage with my Fluke. All 4 tested @ 3.290 V.
Came with M6 terminal bolts and large pack of busbars. I might swap the terminal bolts for stainless vs. mild steel with yellow zinc coating. We'll see.
Very happy so far!

Doug

There was a post on one of the battery threads about someone who stripped a terminal, HeliCoiled it, and bought stainless studs to replace the bolts. He posted pics and a link to the studs. I've gone back and looked, but haven't found his post and I don't remember which thread it was in.

 

[hankcurt]

Thanks for the reply Steve. I appreciate the information I've gained from you an others on the forum.

This little bit of the spec sheet for the LF280 cells is probably not particularly relevant for general use in solar installations because it was in relation to a 1C charge and discharge cycle. It just is bugging me that whatever they mean by 'fixture' affects the cycle life performance so much. There are several research papers about clamping pressure on pouch cells and how it affects cycle life, but the results from those studies don't match up with the spec sheet information, so that made me less sure I was interpreting things correctly.

I am watching others' experience with these cells because I'll have to make a purchase decision in the next couple of months, and these look like a pretty safe bet at this time. Thanks

 

[El Jack]

Steve, I read through the EVE LF280 Spec Sheet that you posted on Thursday, and there is one part of it where I just don't understand what they are talking about. In the table portion, they have this information on cycle life:
View attachment 8282

I think there is a misprint, and one is supposed to be (Without fixture) and the other (With Fixture), but the cycle life difference is significant. It seems they are talking about the clamping pressure the cells are under, but I'm just guessing. 300kgf seems like a lot of pressure.

Later in the same specification document, in the graphs and charts section, they have this page:

View attachment 8283

Once again talking about with or without 'Fixture'. I'm guessing that perhaps the black line is actual test data and the red is projected life? Anyway, they show that with fixture initially drops in capacity more quickly, but then takes 1500 more cycles to get down to 80% capacity. Does anyone have any idea what a 'Fixture' is or how they intend 300kcf of force to be applied to the cell? The google machine has been of little help so far in trying to answer this question.

This caught my eye as well. Does anyone have knowledge on this?

As always, take Chinese translated manuals with a dash of salt

Also if you look closer, the degradation on both up to 750 cycles (the black line) is the same logarithmically - both around 92.8% capacity. It’s the projections beyond which vary. I understand it as ‘fixtures’ help - but 300kgf?!

 

[Sunny Days]

300kgf seems way to much, unless they meant Newtons and someone just ignored it and added kg in translation.

 

[Patrick-B]

My 280Ah LFP cells arrived today! Right on schedule... per Amy's 10 day ETA.
Yesterday, there was no tracking update except pending. Then this morning I received a text from Fedex that they were out for delivery. And then a new text that they were delivered!
I opened the package. The cells were very well packed, two nested heavy cardboard boxes with thick foam wrapping each individual cell. A+ for packing.
I tested voltage with my Fluke. All 4 tested @ 3.290 V.
Came with M6 terminal bolts and large pack of busbars. I might swap the terminal bolts for stainless vs. mild steel with yellow zinc coating. We'll see.
Very happy so far!

Doug

Nice,
How do they look and feel?
Solid and durable? And can you tell if the terminals are solid, or is it possible to 'wiggle' the bolts around a bit?

Those, and the quality / real cycle life vs stated on specs are my biggest doubts about ordering. Together with the m6 bolts. Are these big enough for conducting 200amps all at once?

 

[Patrick-B]

My 280Ah LFP cells arrived today! Right on schedule... per Amy's 10 day ETA.
Yesterday, there was no tracking update except pending. Then this morning I received a text from Fedex that they were out for delivery. And then a new text that they were delivered!
I opened the package. The cells were very well packed, two nested heavy cardboard boxes with thick foam wrapping each individual cell. A+ for packing.
I tested voltage with my Fluke. All 4 tested @ 3.290 V.
Came with M6 terminal bolts and large pack of busbars. I might swap the terminal bolts for stainless vs. mild steel with yellow zinc coating. We'll see.
Very happy so far!

Doug

Nice,
How do they look and feel?
Solid and durable? And can you tell if the terminals are solid, or is it possible to 'wiggle' the bolts around a bit?

Those, and the quality / real cycle life vs stated on specs are my biggest doubts about ordering. Together with the m6 bolts. Are these big enough for conducting 200amps all at once?

 

[Sgt Raven]

Nice,
How do they look and feel?
Solid and durable? And can you tell if the terminals are solid, or is it possible to 'wiggle' the bolts around a bit?

Those, and the quality / real cycle life vs stated on specs are my biggest doubts about ordering. Together with the m6 bolts. Are these big enough for conducting 200amps all at once?

The bolts don't conduct much at. It is the top of terminal in contact with what is attached to the terminal that conducts the amperage.

 

[Steve_S]

As Sgt Raven points out, the bolt is not the main contact, it's the bus bar to the cell post top that counts the most. It's common to think the bolt is more important but that is a partial left over of how people think of Car Batteries with their post & clamp type connections, people associate the bolt being the "post" as such.

EDIT PS: A Dab of Ox-Guard / NOalox between the post & the bus bar is always a good idea BTW, not much, but enough to cover the terminal top to prevent any potential corrosion from occuring.

 

[Sgt Raven]

As Sgt Raven points out, the bolt is not the main contact, it's the bus bar to the cell post top that counts the most. It's common to think the bolt is more important but that is a partial left over of how people think of Car Batteries with their post & clamp type connections, people associate the bolt being the "post" as such.

Look at the side terminal batteries that GM used. There is a large ring on the battery and the cable that mates with it. The bolt is just there to hold the 2 parts together and in contact with each other. The bolt on a clamp style car battery lug, just squeezes the lug to the terminal.

 

[Steve_S]

TECHNICAL UPDATE
The "Bumps" people have mentioned.
I just got these two photo's (combined them to two) from Amy @ Xuba, she peeled the top off to show what is causing these bumps people have reported. NO DEFECT ! It's a manufacturing plug.


This is reassuring and I believe people should not assume things to be the worst case scenario.
Hope that helps reassure folks.

 

[DW SD]

Nice,
How do they look and feel?
Solid and durable? And can you tell if the terminals are solid, or is it possible to 'wiggle' the bolts around a bit?

Those, and the quality / real cycle life vs stated on specs are my biggest doubts about ordering. Together with the m6 bolts. Are these big enough for conducting 200amps all at once?

Hi Patrick,
I'm not sure visible inspection would reveal too much. But, they look fresh and new. And were very carefully packed, which I appreciate.
Based on what I've seen, I'd buy again.

As others stated, the bolt is to clamp, not conduct. My sense is this should work OK. Since I'll be clamping heavy 4/0 cables to each of the battery's end terminals, I will find a way to isolate vibrations and stress.
I'll probably add an adel clamp for each to the plastic housing I'm making.

I won't be able to load test until they are in situ. I'll use my Magnum inverter and loads like a heat gun.
Cheers, Doug

 

[Patrick-B]

Hi Patrick,
I'm not sure visible inspection would reveal too much. But, they look fresh and new. And were very carefully packed, which I appreciate.
Based on what I've seen, I'd buy again.

As others stated, the bolt is to clamp, not conduct. My sense is this should work OK. Since I'll be clamping heavy 4/0 cables to each of the battery's end terminals, I will find a way to isolate vibrations and stress.
I'll probably add an adel clamp for each to the plastic housing I'm making.

I won't be able to load test until they are in situ. I'll use my Magnum inverter and loads like a heat gun.
Cheers, Doug

Thanks for the info. Sounds good to me.
Curious about the load test.

 

[andruby]

Amy had the warehouse prepare a video where they test voltage and internal resistance of each cell. I did not ask for it, so it's nice that they do this regardless.

The voltage and internal resistance look very close. The packaging looks good too. These are 4x 105Ah cells. They do look thicker than I expected from the product pages.

edit: the video was from another customer so I’ve since taken it offline

 

[Steve_S]

A word of wisdom / experience. Don't attach battery cable to the cell terminals as such. It's much more prudent to run a (+) & (-) lead to Battery Terminals from the cells and then attach your cabling to the terminals with a fuse of course on the (+) terminal.

Terminal such as these but there are many varieties to suit various needs.

@andruby She has always provided photo's of the cells you are getting & a little video of the voltage tests. I had suggested that she put a Name Card with them when taking the pics / vid so people know it's theirs that they are seeing.

 

[Carly]

These are 4x 105Ah cells. They do look thicker than I expected from the product pages.

Hopefully they don't send you 280AH cells!