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

[gyrex]

Lithium Ion like the 18650 in my Vape Mods top out at 4.2V These LFP cells should be cut off at 3.65V. You don't gain any useful power above that. The only reason to charge to 3.60V is they will settle down to a lower voltage, once they rest. I'm perfectly fine with stopping at 3.5V. Even there I only gain an extra couple of hours at a slow drain. When you start using them, they will hang out at 3.35V(13.4V) for a long time.

Agreed - the discharge curve on LiFePO4 cells is extremely flat. My point is that the 280Ah claim of this cell is made based on a full charge and discharge of the cell from 4.2 - 2.5V at a low C discharge and unless one does tests within that range, we're not likely to see that 280Ah figure.

Obviously running these cells with these charge/discharge cycles isn't advised over a long period of time if one wishes to prolong the life of the cells since it breaks down the organic electrolytes at a much more rapid rate. Either way, these 280Ah cells appear to be awesome for large solar systems.

 

[Delta-V]

Full capacity test #1
Full capacity test #2

And we wonder why Steve tries to keep everyone on topic. So we don't have 40 pages of clutter.

 

[Sgt Raven]

Agreed - the discharge curve on LiFePO4 cells is extremely flat. My point is that the 280Ah claim of this cell is made based on a full charge and discharge of the cell from 4.2 - 2.5V at a low C discharge and unless one does tests within that range, we're not likely to see that 280Ah figure.

Obviously running these cells with these charge/discharge cycles isn't advised over a long period of time if one wishes to prolong the life of the cells since it breaks down the organic electrolytes at a much more rapid rate. Either way, these 280Ah cells appear to be awesome for large solar systems.

I started my test at 13.9V and it ended at 12.8V...... It was sitting on 0% left by the BMS dashboard from 13.1V to 12.8V...
After it was done, the BMS says it has 308AH. So my test results doesn't jive with your post.

 

[Sgt Raven]

Full capacity test #1
Full capacity test #2

And we wonder why Steve tries to keep everyone on topic. So we don't have 40 pages of clutter.

I am still talking about the same XUBA 280AH cells and my observations about them.

 

[Delta-V]

No issues with you Sgt Raven. I'm noting in general, assuming gyrex may not have known I'd already done a couple full capacity tests; possibly because of the topic clutter.

 

[Patrick-B]

Amy is saying they will have metal battery boxes large enough for 8 cells very soon. I'm holding off doing anything more with my 3d printed supports until I see what they come up with. If these look good I will design 3d print parts to support the cells and hopefully a Chargery BMS in any space remaining in the box.

Yeah. I did not order a batterybox. Because apperently the box had to be shipped seperately, freight calculated by volume. Meaning price for shipment by sea, was $50 to netherlands. The box was $38. And this was the plastic one..

 

[Steve_S]

Thanks for doing these tests. I think if you were to charge and discharge these cells to the specified voltage limits that you'd achieve the advertised capacity.

What I find interesting is that these cells are supposed to be the same as all the other 280Ah cells advertised on Alibaba (https://diysolarforum.com/threads/x...cells-purchase-review.3850/page-33#post-66256) but for some reason, Xuba's listing lists their upper voltage limit to 3.65V, whereas the other sellers advertise 4.2V. Some (including Xuba) seem to list the low cut-off voltage at 2.5V and some as high as 2.7V.

I appreciate that longevity of the cell will be improved by reducing voltage ranges but the manufacturer should be listing the cell's actual maximum and minimum voltage values then allow the customer to decide if they want more capacity with reduced cycles or reduced capacity with more cycles.

XUBA uses the same specs as shown in the EVE LF280 Specifications Document for the cells. What others are advertising and where they get their info from is unknown, you would expect they use the company specs. Wisdom is to follow the Manufacturer Specifications Data, plain & simple.

 

[Mrdanielmh]

Whats the general opinion on top balancing these cells on arrival? Im wondering if i can achieve it with my victron ip22 30a charger.

 

[LanduytG]

WOW!! I paid for my 12 280ah batteries over the weekend. This morning I woke up and had and email from Amy with pictures of my batteries with my name on them. She said they were shipping out today. I choose sea freight as she recommended so in about 30 days or so I should have them at my door.

Greg

 

[LanduytG]

I was just watching the video them measuring each cell. all were 3.33 volts and .14-.18 meg ohms resistance.
Can't wait to get these bad boys. I plan to run these 4S3P and I just keep thinking to have this in AGM like I have in the RV now would be way more money.

I run 3 140ah AGM's now and those were $375 each about 4-5 years ago and they weigh 120 each. So basically I run them to 40-50% DoD or about 170ah. Now I will have 840ah in the same space for about 675ah at 80% DoD and only weighs about 132 poounds. So almost 4 times the available power at 1/3 the weight. All said and done with cells and the 3 BMS I'll have about $1700 in them thats just over $2.50 pre usable AH. To get the same usable power in the current AGM's I'm using would cost $3000 and weigh 960 pounds and usable power cost at $4.50 pre AH.

But this is only possible do to what is now availbale. If I had to by Battle Born or any other pre made battery would be $7.5k.

Greg

 

[rbreding]

I plan to run these 4S3P

As a suggestion please look into 3p4s instead. You could use only one BMS in that config.

 

[LanduytG]

As a suggestion please look into 3p4s instead. You could use only one BMS in that config.

Put the BMS is only good for 120amps. I want to put in a 2kw invertor. Not sure which BMS to use for that config.

Greg

 

[Sgt Raven]

Put the BMS is only good for 120amps. I want to put in a 2kw invertor. Not sure which BMS to use for that config.

Greg

This might be a place to use a more expensive BMS that can handle a higher discharge rate. I think the Chargery can with the right parts. One more expensive or 3 cheaper ones.

 

[rbreding]

Put the BMS is only good for 120amps. I want to put in a 2kw invertor. Not sure which BMS to use for that config.

Greg

I will be using a 120a BMS on my 2p4s setup that will run all the 12v stuff. The victron inverter will be directly connected to the battery and controlled via low voltage cutoff and a relay that is controlled by the BMS as backup.

 

[LanduytG]

Been looking around and cost of a 4s 250amp is $200. Thats what I paid for the 3 100amp units with bluetooth. I see where you guys are coming from but does it really make a big differance? Willing to listen.

Greg

 

[Sgt Raven]

Been looking around and cost of a 4s 250amp is $200. Thats what I paid for the 3 100amp units with bluetooth. I see where you guys are coming from but does it really make a big differance? Willing to listen.

Greg

You've already got them, run them. Setup that way, you could pull any 1 pack out without having to change the others.

 

[Metamorfos]

Are you able to pay with PayPal if you order batteries from Xuba?

 

[LanduytG]

That was and option but I don't use PayPal I used my CC.

Greg

 

[loverofpeace]

Are you able to pay with PayPal if you order batteries from Xuba?

No neither of them will let you pay with PayPal even though it's written on their page. You have to go through the Alibaba payment system, which is a bit annoying as it'll automatically flag your card and you have to send in a photo of your id and the card.

 

[LanduytG]

No neither of them will let you pay with PayPal. You have to go through the Alibaba payment system.

I just ordered mine this past Friday and PayPal was and option. Along with Wire Transfer and other methods.

Greg