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Pic of the assembled packs:

Packs finally arrived!! Little over 100 days to get them to Texas. :rolleyes: They look to be in really good shape, I can see intact QR codes on the cells peeking through the outer plexi case. They are very solid and feel like the cells are are secured inside somehow. And, you can see what...

Thanks, I really appreciate that, especially as a lifepo4 newb. Also, an update.... Pack 2 tested out to 180ah!! I have noticed the voltage differential on both of these packs seems to be pretty good, as in less than 10ma differences between the cells. If I didn't mention it before, these...

Top balance is done on Pack 1. Pack 1 Voltages (after 24hrs) 3.37 3.43 3.42 3.49 Thanks to LuthJ for the top balance procedure, worked flawlessly. Just for kicks, I did a little test. I made a couple sets of my own test leads, and I did a little head-to-head with the banana plugs that came...

I have not received them yet, but I do intend to post back here when I do. I ordered what was in the 176ah link, and received a message from the Xuba contact asking if I'd like the red case on them. I actually did not see the response before they shipped, but I am assuming they sent me the...

Just for kicks, here's the rest of the pics they sent. I agree, that does look like 1/4 stock. Also, some of the terminals in that one pic do look a bit rough, giving some credence to the notion that these could be cells that have had terminal issues, and are being repurposed as "packs". So...

Been a lurker here for a few months, I'd like to start by thanking this community for contributing to all the wonderful knowledge on this site. I am still somewhat new to this, but I have spent time reading most of the long threads here in their entirety, and watching all of Will's vids. I'll...

Yeah, I was curious about how laser welding works, and stumbled across this: https://www.mdpi.com/2313-0105/6/3/47 Those appear to be "lap welds". I won't pretend that I have read the whole document yet, but it looks like it was just recently published. I think the key here, since these...

https://gcaptain.com/maersk-essen-arrives-in-mexico-with-collapsed-containers/

Ok, possible stupid question here. Obviously the negative terminal of said cell is wired to the positive terminal of the next cell over. Connecting the negative lead from the bench charger to that bus bar, and the positive lead to the next bus bar over won't result in any fireworks? I trust...

I did not, I don't have a tester that can do that unfortunately.

Why is that? I have read a few threads about issues stripping the terminal threads, and conductivity issues with stacking BMS leads on the posts with bus bars. This seems like it would resolve both of those problems.

176ah

Good point, hopefully for my purposes, I won't be drawing anywhere near the amps needed for that to be an issue. The highest draw items I have will be an instant pot and the occasional microwave (not at the same time), both around 700w. That's what, <60 amps across 2 packs? I figured absolute...

In that first pic, the terminal has what appears to be a "pattern" of wear on it....like it was clamped or resting on a rough but evenly patterned surface (or more likely, something was clamped down to it...maybe a braided bus bar?) I just posted this pic in a separate thread, and it looks like...

I wasn't sure that was possible if the cells were in series. How would you attach the BMS leads?

I haven't started my travel trailer build yet, so take this with a grain of salt.... I went with flexible panels for the weight issue. SunPower seems to have the best, and one of the only flexible panels I could find that ran at 24v...

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...

Ah sorry, I thought I had posted this.....newer listing from Xuba, with a vid the welding process. They are taped together, so I wouldn't say compressed, but I don't see a gap in between the cells...

Yeah for $625 delivered, its somewhat a leap of faith. And no, I have no illusions they are matched and batched at that price. I wanted to eliminate a variable that might contribute to failure from my inexperience. To HRTKD's point, I am trading some flexibility here with not having to worry...

Ah, is that what that rough patch is? Thanks, I was curious why they wouldn't provide a mechanism to attach the BMS leads, that must be it. I have searched all over for an aluminum screw clamp that looks like the right size. Best I could find was several varieties of copper-based ground...

Top balance is done on Pack 2. Pack 2 Voltages (after 24hrs) 3.34 3.43 3.38 3.38 Also completed capacity test on Pack 1, it was over 178ah (!!) when I stopped the test at 12.2v before it hit the BMS low voltage cutoff. Possible I could have pushed it to 180ah if I let it go all the way to...

I would think aluminum bent like that would exacerbate the problem. The 90 degree angles become failure points as well, with its rigidity. You don't want creased aluminum to be trying to bend itself back and forth over and over, right? Those appear to be copper, or maybe brass? And if that's...

Definitely related to the poor chemistry of convenience store hot dogs and their performance under heat stress. ?

I'm still not clear on how I balance these packs. All the procedures I have seen involve either bench charging the cells in parallel, or hooking up the BMS and just let the BMS balance them over time. Since wiring these cells in parallel is not an option, seems I should (per Luthj) charging...

Just a note on rings vs alligator clips. I was able to push full 10amps from my bench supply (Longwei) just by jumping up to 12awg and using copper alligator clips on the leads. I am not sure rings are really necessary, at least not up to 10 amps anyway. I tested on another thread here, and...

Awesome, that's my solution then. Thanks a ton Luthj!

Or here, even better.....is a pic where I just wired them right in the middle of the dang bus bars. Same same.

Quick update, it's been almost 90 days since I ordered these packs from Xuba. Received a note from them this week stating the cargo ship had an "accident" and will be in Mexico for repairs until sometime in March. Bleh.

It appears to be, but interestingly....I don't see it stated on the web page anywhere.