Xuba Pre-built 277AH LIFEPO4 Battery

[wamcneil]

What the hell???
Welded aluminum bus bars!

You can not disassemble the cells now.
Any swelling or movement of the cells will put stress on the batteries.
Were they laser welded?

Like I said... I've got mixed feelings on the welded terminals, but I'm pretty sure any swelling or movement with tightly bolted terminals would put just as much stress on the cells and/or cause the fasteners to loosen up.
Right now, I wish I could easily replace the one cell. But after I get the batteries finalized and in service, I probably won't ever think about or care how the bussbars are attached.
I'd be curious to see how the welding process is done. With the bussbars being 2mm thick, I don't see how a heat source applied to the top of the bussbar could melt a relatively small area of the bussbar and reliably penetrate into the top of the terminal. I wonder if maybe they use some kind of induction? Or maybe it's a resistance weld using current?

 

[batteryquest]

Sorry if I let the cat out of the bag!

When messaging with Xuba they assured me they had professional assemblers and used a single bms now. I asked them to provide pictures of a current battery they are building to see the difference and they refused.

 

[pmtco2]

Like I said... I've got mixed feelings on the welded terminals, but I'm pretty sure any swelling or movement with tightly bolted terminals would put just as much stress on the cells and/or cause the fasteners to loosen up.
Right now, I wish I could easily replace the one cell. But after I get the batteries finalized and in service, I probably won't ever think about or care how the bussbars are attached.
I'd be curious to see how the welding process is done. With the bussbars being 2mm thick, I don't see how a heat source applied to the top of the bussbar could melt a relatively small area of the bussbar and reliably penetrate into the top of the terminal. I wonder if maybe they use some kind of induction? Or maybe it's a resistance weld using current?

I actually was curious as well, and found some info on how the welding is done on those terminals. I posted it here:

https://diysolarforum.com/threads/xuba-cells-with-laser-welded-bus-bars.16843/post-207959

Xuba has vids of the welding process on some of their ads, this one is for the 280ah cells:

https://www.alibaba.com/product-det...tml?spm=a2700.shop_pl.41413.19.74c641b4VUWYMO

 

[AgroVenturesPeru]

I think part of the problem is that I specified a fully custom box and I hope they can work our these issues to start supplying some really great batteries at a really great price. I wasn't planning on these to be Battle-Born batteries, but I did plan to get workable batteries. Hopefully I will once this is resolved.
"I would also suggest that they do actual capacity testing on each cell"- If you want that level of quality control you'll probably need to buy battle-born batteries and pay battle-born prices. Testing each cell for capacity would greatly increase the total cost of a battery IMO. My contract states "272 ah" so I think they'll be obligated to remedy the reduced capacity.
I have mixed feelings on the welded busbars. On the one hand, welding makes a pretty darn good and reliable electrical connection, and I don't plan to pull more than about 100a from each battery anyway. But on the other hand, replacing the one sketchy cell is not real practical. I could probably get an end-mill for my drill press, clamp the pack into some kind of jig and cut down to the top of the terminal, then rebuild the cell with Cu busbars.
Knowing what I know now... I would have been a LOT more detailed with my specifications...
Assuming they treat me right, I'll probably order from them again.

See, this is why it's good to know your stuff as an end-user when dealing with sellers in this industry. Someone like me, would've bought the thing and been none the wiser. At least we can glean some proper info from people like you. Thank you for your service to the community.

 

[Goombah111]

Here's the BMS

"Max charge voltage: 14.6A"

 

[wamcneil]

Hi all,
Well, it took a while! But I have an update on the Xuba assembled batteries.
I took a chance with Xuba, did not pursue a Trade Assurance claim with Alibaba and let the window for claim expire.
Xuba's Brian Chen and Selina Li negotiated in good faith and agreed to replace my batteries at no charge. I'm very pleased with the outcome and I certainly never expected this level of customer service from an Alibaba seller.
Xuba contracted out the battery assembly, blamed the contractor for the poor workmanship and apologized for the mess.
For the new batteries, they started all over with a new design. Their engineers were not happy with my specifications for overall size and insisted that the housings must be larger, so we agreed on a new box size and the new housings are built to those specifications.
The process took a while; about 4-mo before the replacement batteries shipped. They've been in service for about 10 weeks now.
I've been delaying this updated review because I have yet to open them up to inspect, top balance and get a good capacity test... but wanted to post some pictures and preliminary review.
From the outside, all looks good. Appearance is very nice, nothing gets hot under load and the voltages don't sag at 200a load (100a each).
They're supposed to have Daly 200a BMS inside, but I haven't opened them yet. The the new batteries are riveted around the lid, so it'll take a bit of effort to get them opened and top balanced.
Initial capacity is significantly lower than 280ah. I'm pretty sure this is just because the cells aren't balanced and I think I'll get full capacity after they're properly top balanced. I don't fault Xuba for this, and didn't expect the cells to be meticulously balanced.
Packaging is excellent. The batteries are packed securely with couple-inches of foam on all sides.
I'll update again once I've got the batteries opened up and balanced.
Cheers,
Walter

 

[wamcneil]

Here's another interior picture.
The battery is nice and tidy inside. Busbars are shrink wrapped, and note how all the BMS wiring runs in a neat foam channel down the middle. They welded the bms solder panels on the underside of the busbars.
Cells appear to be EVE cells, judging by the cat-eye shape around the terminals. All of the QR codes are visible. Can't get a real good look at the BMS, but it does appear to be Daly 200a as promised.
Starting to get the battery balanced. Definitely needed

 

[bryn]

that is a lot cleaner than the first battery you received, glad that it was resolved