VariCore 3.2V 90Ah LiFePO4 cells from AliExpress

[carlos1w]

Thanks for posting those, that price for the 150ah cells seems pretty good. It looks like another forum member has ordered from them and all cells tested full capacity (for 280ah cells).

I've been looking at these, CALB 4x200ah for $394 shipped via sea and aluminum cased 4x200ah for $424 shipped via sea. The pages say 2 packs minimum but if you contact them they'll make up an order for one. The company is Dongguan Lightning New Energy Technology Co., Ltd.

Grade A 3.2v Catl 200ah 202ah Lifepo4 Lithium Ion Battery - Buy Lithium Ion Battery,Catl Lifepo4,Lifepo4 200ah Product on Alibaba.com

Grade A 3.2v Catl 200ah 202ah Lifepo4 Lithium Ion Battery - Buy Lithium Ion Battery,Catl Lifepo4,Lifepo4 200ah Product on Alibaba.com

www.alibaba.com

This product is no longer available.

This product is no longer available.

www.alibaba.com

It looks like at least a couple forum members have ordered from them and the capacities for the aluminum cells are true (or may be a little over, indicating new cells). The page for the CALB cells states outright that the 200ah cells have a capacity of 190-195ah, but are matched. They both say they have a 1 year warranty. The CALB cells state that they can discharge at 2C and the aluminum ones at 3C.

The aluminum cells say they are rated to 3500 cycles and the CALB to 2000 cycles... I would think this, along with the actual capacities measured would indicate the aluminum cells are higher grade and the CALB are at least lower grade or maybe used? I haven't asked the seller if they're new or not.

I received a pretty good quote from them for some Al cased 200 Ah cells with some issues (see below).

They (Dongguan Lightning) quote $320 shipped (with taxes and shipping included) which is really awesome. However, they claim there are some defects in the plastic wrapping: They say "The Lishen factory send us the battery without pvc. We use pvc wrapped them. But the worker does not wrapped them perfectly. The appearance is not so good" and added the photos.

What do you guys think? Worth the risk?

 

[Britt]

I received a pretty good quote from them for some Al cased 200 Ah cells with some issues (see below).

They (Dongguan Lightning) quote $320 shipped (with taxes and shipping included) which is really awesome. However, they claim there are some defects in the plastic wrapping: They say "The Lishen factory send us the battery without pvc. We use pvc wrapped them. But the worker does not wrapped them perfectly. The appearance is not so good" and added the photos.

What do you guys think? Worth the risk?

Dang, that's a great price. I personally wouldn't care if it's only a cosmetic issue... did they say if they're new, full capacity and matched?

 

[Gazoo]

I think you can get new 200ah CATL cells from Mr. Dao for around the same price. I haven't placed an order with him but others have. I will be placing my order very soon...within a week. I will be ordering either 4 EVE 280ah EVE cells or 8 200ah CATL cells. I don't mean to promote anyone and he is a new seller and has been very active on the forum.

What are the main brands of LFP batteries sold in China

The largest battery manufacturers in China are CATL and BYD, both of which have very good quality, but CATL prefers NCM batteries and BYD prefers LFP batteries However, the shape of BYD's battery is not popular. People are more interested in the CATL shape of the battery. In addition to...

diysolarforum.com

 

[carlos1w]

Dang, that's a great price. I personally wouldn't care if it's only a cosmetic issue... did they say if they're new, full capacity and matched?

It is very hard to get a definite answer from these guys... There is always some ambiguity. They claim "The Lishen factory send us the battery without pvc", but if you ask specifically "are they grade A new cells" there is no definite response. It is frustrating. Anny did say the 152 Ah cells were new and grade A so I am more inclined to go with her. Overall the price per kWh is about the same for both offers so I am unsure as of now.

 

[carlos1w]

lots of stuff deleted

Look pal, I did not insult you. Stop taking things personally. I have a BS in Electronics (and 29 years of experience in it--in repair, design and build several digital and analog equipment for various research labs), a Ph.D. in Physics (in 1997), and have been doing research and teaching in physics (at a major US research university) and electronics (more of a hobby, but teach an electronics course at a major university every year) for more than 20 years . You can call whatever you want, but keep it civil and stop taking any discussion as a personal insult. And stop calling other people stupid without really knowing them. You are being very childish. What are you? 12?

I repeat: you set a GOOD PSU at 3.50 V and it CANNOT overcharge anything over 3.50 V (that is basic physics), so given that LiFePO4 voltage vs. charge curve means that 100% is ABOVE 3.50 V then you cannot overcharge it unless there is some problem: for example, your PSU may not be so good and may produce short period spikes that elevate the voltage above that. That is a problem with the PSU. Alternatively that cell was bad to begin with and 3.50 V was more than it really could take. Would have failed with a BMS too.

Also bear in mind that many choose not to charge above certain voltage (i.e., at 3.30 V LiFePO4 has achieved some 90-95% charge). 3.50 is getting really close to the full charge. YMMV

Do you think a chinese made BMS (that may charge LiFePO4 to 3.60 or 3.65 V) will protect your cell better than a good PSU working properly? Sigh.

 

[Frank in Thailand]

I received a pretty good quote from them for some Al cased 200 Ah cells with some issues (see below).

What do you guys think? Worth the risk?

Why are you asking us??
"expert in electronics and physics"?

You already know.
As LiFePO4 is electronics.

Wake-up call in this thread...
The seller doesn't make the cells, they are box movers.

CATB & BYI are the biggest factories.
The EVE cells many of the forum members buy / bought are from smaller factory.

The seller can't guarantee anything.
Nice words during sales, you can't really expect to receive any warranty after the sales assurance period of Alibaba have passed.
That's 14 days.
After this, you are on your own.

You might try to contact the factory directly to receive warranty...
I wish you good luck with it.

Many sellers make the specifications look more nice.
AliExpress makes it totally crazy

(The gift controller is 750watt)

Naturally you can thrust the advertised number and think that (like above) you get 6000 watt wind turbine.
Or use your brain, compare the specifications with other, similar products to find "average" specifications.

LiFePO4 a few years back did 500 cycles, if you got lucky.
Then it was dead.

Modern cells are a lot better.
If you use low C rates, keep the charge between 10 and 90%, and around 25-30 degrees Celsius, you might get lucky and manage to have 3500 cycles, and have 80% capacity left after the 3500.

Might and lucky..
Magical words.

Realistic?
2000 cycles on above low C rate and partial cycle is doable.
You can expect to reach this number.

Anything more is welcome!

I'm expert in real life experiences.
What does happen and not what fancy specifications tell you.

Buying from China, especially via low QA sites like Alibaba and AliExpress is a gamble.

If you like warranty, use Amazon.

@ghostwriter66 made excellent guide on how to order and how to communicate with Chinese seller
How to order Chinese Batteries

Don't expect Chinese to think like an American.
You are in their backyard and play by their rules.
There are HUGE cultural differences.

This can avoid disappointment, like to even think about warranty.

CATB & BYI can have the better quality.
Don't expect those to end up at low price site like Alibaba.

The packaging (aluminium or plastic) doesn't say anything about the quality of the cells.
Even a brand name is dubious to use for quality measurements..

You don't buy new Mercedes for the price of a TaTa in China and can possibly expect to have all the goodies that come with buying Mercedes from the Mercedes dealer.

Maybe you can..
I can't, being expert in real life.

 

[Frank in Thailand]

.lots of stuff deleted

Hello...

Who is starting to call anyone stupid?
Or tells that something did not happen while he was not here?

I've told you the basic ingredients.
New cell, new lab power supply.
Both tested with multimeter.

As "expert" you should be able to tell what went wrong and how it could have been prevented.

Yes.
I agree.
A good PSU should not have done this.

Next step.
How do you know a PSU is good?
Before you use it?

I do not know what happened.
I can tell you the start and end situation and the "QA" done to confirm functionality.

You tell me.
What went wrong and how could the problem that did occur, be prevented

 

[Frank in Thailand]

This is not meant to piss you off, genuine question.

As I don't know.

I share the many mistakes I make and errors I experience with cheaper Chinese products.
Sometimes to laugh about, as some of my mistake are plain stupid.
Mostly to help others to prevent them from making the same mistake.

@Jeremiah bought 3 similar PSU.
I told him about my experience during the charge, where leaving the charge not supervised was a mistake.

That did result in atleast one cell not defective as one of his 3 PSU suddenly spiked in Amperage.
He monitored for hours and hours.

That is real life and how I contribute in this forum.
Not by stating that something could not have happened, being "expert".

Theory is miles away from what happens in real life.

That it should not have happened, I agree. It did.

There are no good power supplies.
Only the ones that aren't defective yet.
They all get defective, being after hours, weeks, decades.

I share real life experiences, and I don't need to make them up or change numbers to make it look more interesting or what ever some people need to be creative about.

If you state it could not have happened, you are calling me a liar.
That, I do take personally.

I don't need to lie to make a story look better or more thrilling..

Before you make a statement that I do lie about something, be ready to back that up, as it is a personal attack on my integrity.

 

[carlos1w]

Look, I merely stated that if a PSU is set to 3.50 V (and it displays the correct V) it cannot put more than 3.50 V. Then you got all combative saying I knew nothing about it (which I explained later why I have credentials and that I know something about it). Posting with angry emoticons, and all... In a technical forum. All too personal and too upset. OK. To each his own.

I also explained reasonably well what could go wrong (PSU putting out more V than it stated, perhaps in short pulses; or cell being actually defective, in other words would have failed with a BMS anyway).

Then you also say "Buying from China, especially via low QA sites like Alibaba and AliExpress is a gamble." Yes, we know it. You know it... and you buy at AB and AE. And so do we... I am willing to take a risk if it costs 1/2 of what it costs at Amazon (whose warranty is also not as good as you may imagine).

And "Please do study. Become educated." Yes... That is why I am asking questions on things I don't know, and getting "real life knowledge" from people who may have experienced some sellers/vendors at AE and AB. And I am thankful for the responses (which I thank explicitly and/or with a "Like"). When I make a mistake, I recognize it (check my response when I was corrected about BMS functions and DC-DC coupler, I understood my mistake and learned from the responses---that is how we scientists operate, we try to learn and not repeat mistakes).

"Why are you asking us?? "expert in electronics and physics"? You already know. As LiFePO4 is electronics."
Really? You know about complexity and emerging phenomena? And no, LiFePO4 is not electronics, it is electrochemistry. And quantum mechanics, if you want to go deeper. But alas, a VERY VERY VERY complex system (nanometer size cavities with complex shapes, and electrolytes that when they enter change the shape of the cavities, etc.). I was a juror in a M.S. Defense on development of sodium batteries 3 years ago in France. It is very difficult, and a lot of empirical data. WHY AM I "ASKING US" because knowing whether some particular vendor or manufacturer is more or less well known or reputable is not electronics or physics (unless you think the basic equations of quantum mechanics and statistical thermodynamics can predict the behavior of a person...). So that is where experience counts. You give good advice on some of these topics and I appreciate it.

I also try to share my knowledge on what I know (and electricity, basic electrochemistry, etc., I do...). And I explained what were possible caused of what you said happened to your cells. But you got aggressive for my responses and claimed I called you a liar. No, sir, I just claimed that you were either wrong or something else happened. Take it or leave it.

Let me explain you one more thing: you said "You can set at CC or CV. All I can think of it was accidentally set to constant current". That should not be a problem if you set the CV limit UNDER what you final V is desired. In other words, if you set your CV = 3.50 V and your CC = 5.00 A what the PSU does is sets a MAXIMUM V = 3.50 V, and a MAXIMUM I = 5.00 A. It will not push 5.00 A if the voltage would have to be higher than 3.50 V for it to happen. So the correct way to set up things:

0) Disconnect PSU from anything.
1) With open connections set the V to the desired maximum value (e.g., 3.50 V).
2) With shorted leads from the PSU (now the V should show 0 or close to 0), set the maximum desired I (e.g., 5.00 A).
4) Now you can connect the PSU to the cell.

It will NOT go over 5.00 A or over 3.50 V (assuming it works correctly, of course).

"Theory is miles away from what happens in real life." No, not really. Theory is the basis to understand real life. Not a complete basis, but without it you get much less understanding.

Please keep it to the issue of the discussion.

This is my last response to your rants. I will not respond anymore to this thread unless it is really about this thread.

 

[Jeremiah]

Look, I merely stated that if a PSU is set to 3.50 V (and it displays the correct V) it cannot put more than 3.50 V. Then you got all combative saying I knew nothing about it (which I explained later why I have credentials and that I know something about it). Posting with angry emoticons, and all... In a technical forum. All too personal and too upset. OK. To each his own.

I also explained reasonably well what could go wrong (PSU putting out more V than it stated, perhaps in short pulses; or cell being actually defective, in other words would have failed with a BMS anyway).

Then you also say "Buying from China, especially via low QA sites like Alibaba and AliExpress is a gamble." Yes, we know it. You know it... and you buy at AB and AE. And so do we... I am willing to take a risk if it costs 1/2 of what it costs at Amazon (whose warranty is also not as good as you may imagine).

And "Please do study. Become educated." Yes... That is why I am asking questions on things I don't know, and getting "real life knowledge" from people who may have experienced some sellers/vendors at AE and AB. And I am thankful for the responses (which I thank explicitly and/or with a "Like"). When I make a mistake, I recognize it (check my response when I was corrected about BMS functions and DC-DC coupler, I understood my mistake and learned from the responses---that is how we scientists operate, we try to learn and not repeat mistakes).

"Why are you asking us?? "expert in electronics and physics"? You already know. As LiFePO4 is electronics."
Really? You know about complexity and emerging phenomena? And no, LiFePO4 is not electronics, it is electrochemistry. And quantum mechanics, if you want to go deeper. But alas, a VERY VERY VERY complex system (nanometer size cavities with complex shapes, and electrolytes that when they enter change the shape of the cavities, etc.). I was a juror in a M.S. Defense on development of sodium batteries 3 years ago in France. It is very difficult, and a lot of empirical data. WHY AM I "ASKING US" because knowing whether some particular vendor or manufacturer is more or less well known or reputable is not electronics or physics (unless you think the basic equations of quantum mechanics and statistical thermodynamics can predict the behavior of a person...). So that is where experience counts. You give good advice on some of these topics and I appreciate it.

I also try to share my knowledge on what I know (and electricity, basic electrochemistry, etc., I do...). And I explained what were possible caused of what you said happened to your cells. But you got aggressive for my responses and claimed I called you a liar. No, sir, I just claimed that you were either wrong or something else happened. Take it or leave it.

Let me explain you one more thing: you said "You can set at CC or CV. All I can think of it was accidentally set to constant current". That should not be a problem if you set the CV limit UNDER what you final V is desired. In other words, if you set your CV = 3.50 V and your CC = 5.00 A what the PSU does is sets a MAXIMUM V = 3.50 V, and a MAXIMUM I = 5.00 A. It will not push 5.00 A if the voltage would have to be higher than 3.50 V for it to happen. So the correct way to set up things:

0) Disconnect PSU from anything.
1) With open connections set the V to the desired maximum value (e.g., 3.50 V).
2) With shorted leads from the PSU (now the V should show 0 or close to 0), set the maximum desired I (e.g., 5.00 A).
4) Now you can connect the PSU to the cell.

It will NOT go over 5.00 A or over 3.50 V (assuming it works correctly, of course).

"Theory is miles away from what happens in real life." No, not really. Theory is the basis to understand real life. Not a complete basis, but without it you get much less understanding.

Please keep it to the issue of the discussion.

This is my last response to your rants. I will not respond anymore to this thread unless it is really about this thread.

Yeah I have 3 identical DC bench chargers I got on AB.
1 of them I witnessed twice suddenly decide to spike it's voltage up over 4.
This is what @fhorst is talking about. I got these from an Alibaba seller with nice ratings.
Since then it's been fine. All 3 of them seem to work great but there was those 2 times it jumped in voltage. Of course I set the voltage on them when they are not connected to a cell. I have a sticker on that one and it is not trusted to take cells to 3.65. When they are very low I let it help out and will do some unattended stuff but I have an alarm set so the final few hours it's out of the game and I keep an eye on the others since they are from the same manufacturer.

I'm using 3x 32v 10a Dc bench power supplies

 

[carlos1w]

Yeah I have 3 identical DC bench chargers I got on AB.
1 of them I witnessed twice suddenly decide to spike it's voltage up over 4.
This is what @fhorst is talking about. I got these from an Alibaba seller with nice ratings.
Since then it's been fine. All 3 of them seem to work great but there was those 2 times it jumped in voltage. Of course I set the voltage on them when they are not connected to a cell. I have a sticker on that one and it is not trusted to take cells to 3.65. When they are very low I let it help out and will do some unattended stuff but I have an alarm set so the final few hours it's out of the game and I keep an eye on the others since they are from the same manufacturer.

That makes sense. They shouldn't but ... You know, it has been a while since I dealt with the innards of a switch mode PSU (and these cheap 30V 10A PSUs are all switch mode PSU's---I have a couple, and also have a couple of Linear PSUs that only do 30V 3 A and weigh about 5x more and get a lot hotter). In SOME switch mode PSUs there is a requirement to have some minimal current draw, otherwise the voltage regulation may be not perfect. This is common with PC power supplies because they always have a load, but this shouldn't be the case for benchtop PSUs... Oh, well, you know quality control is not so great!

 

[Frank in Thailand]

That's what I've been saying at the start.

Claiming that I must have made mistake as you are "expert in electronics and physics" and know it is not possible..
In that order..

I didn't.
Except maybe to leave the charge unattended.

I'm sure you have a lot more knowledge about many things and for sure like to get your advice in the future.

Just don't make statements about something you don't know enough about, like my bloated cell, and how it happened.

That it happened and showing the bloating, have prevented several cells from suffering the same fate.

It's different reading about it and seeing it.

@Jeremiah shared with me that till 3.5v (so 3.49) takes ages (hours and hours) to get at / over 3.50
After this, it's a matter of just minutes to get to 3.65...

Really really fast.

Something that you won't expect, or I didn't.
Minutes..

That, together with the unstable spike for recharge a cell after capacity test..
Enough to make it bloated.

 

[Gazoo]

Just don't make statements about something you don't know enough about, like my bloated cell, and how it happened.

From reading your posts sounds like you have a love relationship with your bloated cell...

Sorry, couldn't resist...j/k

 

[carlos1w]

peace, brother

 

[Frank in Thailand]

Love/hate relationship...

Really educational moment.
After having my cell bloated I've done a lot more research about LiFePO4, bloating and gassing.

Learned a lot!!

I did replace the cell, as "that is what you are supposed to do".

Looking back, there was no real need to do so.
It might have some capacity loss, a few%.
Most cells aren't exactly what they are rated for.
Jeremiah's rated 120Ah have up to 127Ah
Losing a few% won't really influence total capacity (736Ah rated)

My costs for replacement where $50
Learned a lot!

Bloating at LiFePO4 is NOT the same as bloating at Lithium polymer.
The last one is dangerous and should not be used.
For LiFePO4, next time (of there would be) I won't buy a new cell!

 

[svetz]

Watch the voltage on the power supply...

 

[tictag]

+1 for Mehdi ... an iranian canadian national treasure

 

[ghostwriter66]

Watch the voltage on the power supply...

My professor in EE 401 use to play all this guys stuff during the breaks ... I LOVE THIS GUY .. I have learned more about what NOT to do from him then anyone .. and you can tell he's not faking it ... funniest guy on the net

 

[ghostwriter66]

peace, brother

Just make sure you pay with a CREDIT CARD and if its not what its suppose to be open a complaint and you will be fine ... It should take you about 60-90 days to get the batteries ...keep us posted as the results ... I avoid Aliexpress and normally use Alibaba for several reasons but thats not important here ... good luck ..

 

[carlos1w]

+1 for Mehdi ... an iranian canadian national treasure

I love watching his channel... My family not so much, though