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diy solar

This seems way too good to be true ... 420ah from a "normal size" LifePO4 cell

So the cells finally arrived, nearly three months after ordering.
We were 99.9999% they could not be 420ah (we did have our eyes open so please comment appropriately), but curiosity won.
The question was really: How (good or) bad are the cells?

Individual cells came out at:
  1. 242ah
  2. 244ah
  3. 242ah
  4. 243ah
This was done at around 20°C at 15amps for each cell. The test took under 17 hours. We dropped the amps in the last hour just to eke out a bit more.

So .... less than 60% of the stated capacity. Not good.

Although the voltages were "similar" upon delivery, clearly the SOC was wildly different. We started off with a 14.6v charge in series with BMS set to HVD at 3.65v. This lasted only around 5-6 hours (Amy's cells normally take around 10-12 hours). We then connected the cells in parallel and top balanced at 3.65v which took another 12 hours or so (Amy's cells usually take less than one hour) - suggesting the the SOC upon arrival had a very big delta. We had also weighed the cells and although I can't remember the exact weights there was around a 0.15kg delta which is huge.

All in all those cells are a fail and we shall of course be attempting a clawback of our money.
We have clear correspondence from them that every cell is a minimum of 420ah.

They are now back in series and being charged at 20a. I want to see what the delta looks like between the knees, and then to see how close (or far) they are at full SOC. After two hours the delta is 0.015 which is not too bad. Amy's are normally 0.00something
 
So the cells finally arrived, nearly three months after ordering.
We were 99.9999% they could not be 420ah (we did have our eyes open so please comment appropriately), but curiosity won.
The question was really: How (good or) bad are the cells?

Individual cells came out at:
  1. 242ah
  2. 244ah
  3. 242ah
  4. 243ah
This was done at around 20°C at 15amps for each cell. The test took under 17 hours. We dropped the amps in the last hour just to eke out a bit more.

So .... less than 60% of the stated capacity. Not good.

Although the voltages were "similar" upon delivery, clearly the SOC was wildly different. We started off with a 14.6v charge in series with BMS set to HVD at 3.65v. This lasted only around 5-6 hours (Amy's cells normally take around 10-12 hours). We then connected the cells in parallel and top balanced at 3.65v which took another 12 hours or so (Amy's cells usually take less than one hour) - suggesting the the SOC upon arrival had a very big delta. We had also weighed the cells and although I can't remember the exact weights there was around a 0.15kg delta which is huge.

All in all those cells are a fail and we shall of course be attempting a clawback of our money.
We have clear correspondence from them that every cell is a minimum of 420ah.

They are now back in series and being charged at 20a. I want to see what the delta looks like between the knees, and then to see how close (or far) they are at full SOC. After two hours the delta is 0.015 which is not too bad. Amy's are normally 0.00something
I received my delivery as well .. and first two tested were also really low. #1 272 ah. #2 267ah. as received 0.026 v cell variation . as recived used std practices to equalize cells than .1 charge rate and a 1 hour soak.
 
Let us know how the dispute process goes. A friend of mine saw these and wanted to buy them too. I told him that there is no way in hell the exact same size and weight (compared to 280AH eve cells) could produce 420AH.
 
We raised a dispute with AliExpress who have said that we will be refunded 100% but will need to return the cells to the seller (at our expense). Essentially this whole "experiment" is going to cost us around £100 in return shipping fees.

Our credit card company may or may not have clawed the money back - but they also wanted to know if we'd returned the goods first.

I'd asked for advice in this thread:

...but as no-one was able to advise us we decided to take the hit of £100 in order to ensure that we get the bulk of the money back. We could have gambled that our bank would claw the money back and expect the seller to collect the goods at his/her expense, and our thinking was based on the premise that they blatantly lied. Having blatantly lied why should the transaction cost us anything? But would the bank have agreed with us? I'm not sure. They could have said that the seller didn't blatantly lie and that the goods were merely faulty.

I guess these cells will find their way to some poor sucker somewhere. I doubt these sellers would hesitate to sell them to someone as brand new grade "A". Other than the scratch marks on the terminal (which I'm sure you'd agree can't be helped) they are in perfect condition and have only had about four cycles never exceeding 3.65v and never lower than 2.5v
 
I have punched 4 batteries as well and all were at 265 to 274 AH .. aliexpress said I need to contact the seller and I told aliexpress I sent 4 messages over the month with no response.. I am glad I only bought 4, I originally only wanted 2 to test but was told they came as a 4 matched set … boy did I swallow a line of BS ..
 
I have punched 4 batteries as well and all were at 265 to 274 AH .. aliexpress said I need to contact the seller and I told aliexpress I sent 4 messages over the month with no response.. I am glad I only bought 4, I originally only wanted 2 to test but was told they came as a 4 matched set … boy did I swallow a line of BS ..
Did you also buy from Shop910787018 Store?
 
We raised a dispute with AliExpress who have said that we will be refunded 100% but will need to return the cells to the seller (at our expense). Essentially this whole "experiment" is going to cost us around £100 in return shipping fees.

Our credit card company may or may not have clawed the money back - but they also wanted to know if we'd returned the goods first.

I'd asked for advice in this thread:

...but as no-one was able to advise us we decided to take the hit of £100 in order to ensure that we get the bulk of the money back. We could have gambled that our bank would claw the money back and expect the seller to collect the goods at his/her expense, and our thinking was based on the premise that they blatantly lied. Having blatantly lied why should the transaction cost us anything? But would the bank have agreed with us? I'm not sure. They could have said that the seller didn't blatantly lie and that the goods were merely faulty.

I guess these cells will find their way to some poor sucker somewhere. I doubt these sellers would hesitate to sell them to someone as brand new grade "A". Other than the scratch marks on the terminal (which I'm sure you'd agree can't be helped) they are in perfect condition and have only had about four cycles never exceeding 3.65v and never lower than 2.5v
I don't know if it will do any good, but I would not accept settlement and would insist that seller pay for return shipping since the product was not as advertised. Not doing so encourages this continued practice. It is in no way your fault that seller misrepresented the product.

That said, I wonder if the dispute process would have been any better if you had ordered through alibaba as opposed to aliexpress.
 
Has anyone actually tried these guys?


I'd be tempted just to see how close to capacity they are. 420ah in my rig would be .... nice
But TBH they are very new and their store name looks a bit like the ID supplied by AliExpress. Also can't find them on Alibaba.
I bought 20 of these cells and tested them: about 240Ah. I am now trying to get my money back.
 
It’s horrible, why does the advertisement write 420Ah when it’s only so low?
 
It’s horrible, why does the advertisement write 420Ah when it’s only so low?
Blatant lies.

How many of their customers have the capability to capacity test?
Probably around 1 in 4? If so, 3/4 of their sales will not be returned. The math works for them, but wondering how well they sleep.
 
Criminals likely sleep well on the funds from their ill gotten gains. It is their job, and the booty is job satisfaction to them.
 
Blatant lies.

How many of their customers have the capability to capacity test?
Probably around 1 in 4? If so, 3/4 of their sales will not be returned. The math works for them, but wondering how well they sleep.
I am very sorry for your encounter with such a supplier. Hope you can get the corresponding
 
This is definitely not the fault of our readers. The big 420Ah in the advertisement, everyone knows?
That store is full of scam. I laso wonder how many buyers actually verify the capacity, it shows 85% positive feedback.
The 320Ah only weighted in at 4kg LOL! and the 420Ah cell weighted in at the same weight as 280Ah cell.


Product specifications

Product name: Lithium phosphate iron
Material: Aluminum
Rated capacity: 320Ah
Minimum capacity: 320Ah
Internal impedance: 0.1~0.5mΩ
Rated voltage: 3.2V
Size (L * W * H): 210*175*55mm(+/-10mm)
Weight: about 4kg
Recommended current constant: 320A (1C)
Discharge termination voltage: 2.5V
Recommended constant current: 320A (1C)
Charging voltage: 3.65V
Maximum continuous discharge current: 320A (1C)
Life cycle (90% DOD): 6000
Charging temperature: -5~60°C
Discharge temperature: -30~60°C
 
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