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

I think this is capacity test #6. Another desirable outcome.

8 Xuba 3.2V 280Ah cells (24V nominal) - Rated capacity 7,168Wh

I set the Inverter/ Charger to 27V charging. Rested over night to 26.80V.

Test Range
Upper limit: 26.80V (rested voltage)

Lower limits (varying low C-rate loads):
25.24V, 5,833Wh = 81% usable capacity
25.27V, 6,253Wh = 87% usable capacity
25.52V, 6,444Wh = 89% usable capacity

1st Pic - Test Begins, Inverter off, battery rested all night.
View attachment 12102

2nd Pic - Inverter powered on. The 3 voltage readings show slightly different from one another.
View attachment 12108

3rd Pic - Powered stuff on, coffee maker & home office stuff. Noticed 2V drop right off the bat. Something to factor in when considering range usage.
View attachment 12103

4th Pic - 81% usable capacity
View attachment 12104

5th Pic - 87% usable capacity. Met 85% goal. Shut everything off soon after. Bedtime.
View attachment 12110

6th Pic - Battery rested over night. About a 0.41V recovery. Inverter off
View attachment 12105

7th Pic - The next morning, out of curiosity, I ran the coffee maker again to see if the battery's lower voltage would drop so much to trigger inverter cut-off (shutdown). It held up.
View attachment 12106

8th Pic - Finished brewing coffee. Inverter off. Ended test. Overall used capacity, about 89% @25.5V.
View attachment 12107

I did a similar test about a week ago where I charged the battery to 26.80V, but I set the charger to 26.80V, let the battery rest a bit, the voltage would drop, I'd charge it again, let it rest, the voltage would drop, charge again, etc... Did this numerous times and kept trying to stabilize the voltage to 26.80V. Still dropped. The best I got it to was 26.76V without wasting another day of fussing around.

The difference this time was I charged to a higher 27V then let the battery rest to 26.80V. Got a much better outcome this time compared to before.

So, it looks like a range of 27V - 25V is looking pretty reasonable to allow for some voltage fluctuation (charging, resting, under load) and still get a decent usable capacity of 80% - 90%.
Delta, when you say you "charged", was this via utility or PV?
My 32 cells came in and i was able to make 3 24v batteries (24 cells) using cells that were identically balanced of of the boat, 3.301. I had a few more of those, a few that were really close, and then one black sheep at 3.269. I made my 4th battery the misfit one, with the less harmonious cells put together. I tried using Will's little 5a charger, that was going nowhere, so I said screw it and plugged it in...started charging via PV. Just one day of cruddy cloudy weather and she's perfectly balanced on her own. No BMS. But, when charging is removed, and a tiny load is out on, like a 75w fan for a while, that cells seems to always dip quicker.

In fact, when charging stops all the cells do there own thing a bit and get out of balance, only to find there equilibrium again when charging. Do you see similar behavior.
It's crazy that you are getting that much power between 2 volts. It doesn't take much for my 2.25kw array to get them to 27v. I'm going to start running tests using your standards. I have seen nothing that tells me not to. Will talks about 29.2, but man, I don't know what it would take to get these that high. Seems almost impossible.
Quick question...does yours charge alright via 120v utility? For some reason, my LV2424s will plug into and recognize the utility connection, but will not charge these cells. Only PV will. Which is mostly fine, but I can't figure why. Doesn't seem to be a setting issue that I can see and the LV2424s SCC would charge my old BYD batteries just fine. It was a different and probably inferior charge than PV, but it worked on some level.
Appreciate any insight and experience.
 
Hey Delt, just saw this old post too. You said, "I went with a 8S2P configuration (8-cell Series packs, 2 Paralleled together) instead of 2P8S (2 cells paralleled, 8 in Series) to make one big 24V battery. Inverter connected to opposite terminals (- on one pack, + on the other pack)."

I have been thinking I would do the same on one of my systems. So you just put each battery together 8s, and then each had a free positive and a free negative. So you attach the negatives together to each other and positives to each other, and then just pick one of the two terminals for each to run to the pos/neg of the inverter. Is that right?
 
most of alibaba vendors do, but charge extra to compensate for PayPal fees. ask Amy to be sure
When I went to purchase directly w/ a credit card (not Paypal) there was going to be a +$14 fee that was waived if you were a first-time Alibaba user and opted to save your CC info (up to $25 credit). Every other payment method (bank transfer, wire, etc) also carried a significant fee. I'm not clear how to avoid these fees on Alibaba in the future.
 
Delta, when you say you "charged", was this via utility or PV?
My 32 cells came in and i was able to make 3 24v batteries (24 cells) using cells that were identically balanced of of the boat, 3.301. I had a few more of those, a few that were really close, and then one black sheep at 3.269. I made my 4th battery the misfit one, with the less harmonious cells put together. I tried using Will's little 5a charger, that was going nowhere, so I said screw it and plugged it in...started charging via PV. Just one day of cruddy cloudy weather and she's perfectly balanced on her own. No BMS. But, when charging is removed, and a tiny load is out on, like a 75w fan for a while, that cells seems to always dip quicker.

In fact, when charging stops all the cells do there own thing a bit and get out of balance, only to find there equilibrium again when charging. Do you see similar behavior.
It's crazy that you are getting that much power between 2 volts. It doesn't take much for my 2.25kw array to get them to 27v. I'm going to start running tests using your standards. I have seen nothing that tells me not to. Will talks about 29.2, but man, I don't know what it would take to get these that high. Seems almost impossible.
Quick question...does yours charge alright via 120v utility? For some reason, my LV2424s will plug into and recognize the utility connection, but will not charge these cells. Only PV will. Which is mostly fine, but I can't figure why. Doesn't seem to be a setting issue that I can see and the LV2424s SCC would charge my old BYD batteries just fine. It was a different and probably inferior charge than PV, but it worked on some level.
Appreciate any insight and experience.
I've not had any issues charging a number of different ways, utility or PV. I've used the old-school Progressive Dynamics 24V@25A designed for lead acid batteries (mainly for bulk charging). I have a cheap 24V@15A power supply that came with a Shunbin LiFePO4 battery box I bought back in November. I also have a variable power supply to help with individual cell charging, fine-tune or top balance charging. I recently bought a Samlex 4000W inverter/ charger that makes utility charging simple and reliable, so that's my go to now if I need to charge via utility. I haven't charged by utility lately. I also have a a couple of gas generators as last resort (ie. hurricane season now).

I've been charging by PV (1kW array) all the time lately. I recently bought more panels, 6 x 390W, but now dealing with shading issues before I permanently setup 3 pole-mounts on the side of my backyard. I also recently transitioned from the Epever 40A@24V charge controller to a Midnite Solar 150 Classic with Wizbang Jr. Needed something to support the new 2.3kW array @94A (panels paralleled due to shading challenges).

The PV charge profile I'm using now: 28.5V Absorb (10 minutes), 27.3V Float. After trying various PV charge settings and tests, I can see why folks are so ambiguous with definitive settings. Different configurations and scenarios can make it tricky for a catch-all optimal profile.

My 16 Xuba 280Ah cells (~14kWh, 24V@560Ah) have been working great! I currently average about 3 - 5 kWh a day. Powers my home office as I've been working from home lately. My 2 cheap 15A BMS's have been working great as well. Cells are staying balanced each day. No complaints.
 
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Hey Delt, just saw this old post too. You said, "I went with a 8S2P configuration (8-cell Series packs, 2 Paralleled together) instead of 2P8S (2 cells paralleled, 8 in Series) to make one big 24V battery. Inverter connected to opposite terminals (- on one pack, + on the other pack)."

I have been thinking I would do the same on one of my systems. So you just put each battery together 8s, and then each had a free positive and a free negative. So you attach the negatives together to each other and positives to each other, and then just pick one of the two terminals for each to run to the pos/neg of the inverter. Is that right?
Yes, 2 packs of 8 cells paralleled together (24V@560Ah), negative to negative, positive to positive, I'm using 3/0 AWG lugged cables. Inverter Positive connection to Pack 1, inverter Negative connection to Pack 2. I have my solar charge controller connected to the Samlex inverter/ charger input connections. Each pack voltage closely match each other and all cells are staying balanced (using cheap 24V 8S 15A BMS per pack, just for balancing). To be expected as I'm averaging a low C-rate.
 
When you say 'connect' to the battery, you mean after installing separate battery terminals, right? not directly to the battery positive and BMS negative lead?
 
Amy just messaged that:

Shipping by sea (door-to-door) channels and ordinary Air Frieght have not been restored, only express delivery can arrive to Canada
The super fast shipping (8 working days) to interior BC, Canada is $623 USD. Has anyone been able to get the cheaper sea freight shipping from anyone recently?
EDIT: Sorry, wrong thread. Meant for the Canada one. Please delete.
 
I heard from Amy and my order went to logistics Monday and should be on their way shortly... (y)
 

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Can someone who's received their EVE batteries from Xuba measure the exact dimensions in mm? Thanks!
 
State of charge doesn't change the physical dimensions of the individual cells.
I think there is a thread around here that shows it indeed does. That is why when cells go in cradles, and then joined, they can swell up a bit. Like the end of a Thanksgiving dinner, the tummy sticks out. Like a dickydoo sorta..
 
I got a FedEx tracking # today from Xuba on Alibaba... shipping from CA, ETA of 6/24??? o_O
 
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