New LFP Cell Capacity Expectations

[riverbug]

I have been communicating with a rep for a company that seems to be reputable on this forum and in some YouTube videos. After getting many questions answered I was feeling very comfortable and just had two final questions before ordering. One question was just clarifying the cost difference between purchasing stock from overseas vs out of their US warehouse which has the supply of cells and BMS that I would like. The other question and the reason for posting here follows (note that the order will be for 8 (possibly 16) Eve LF280K cells:

Question: Last question (I think)…if the cells do not test at 280ah, would I be working with you to resolve?
Response: The capacity might be around 270-280ah. It is normal.

This will be my first foray into building my own batteries. In all my research, I thought new good quality cells will have a minimum of the stated Ah capacity (typically more than the stated capacity) and anything below the stated capacity suggests sub-par or used cells. Is my understanding correct or misguided?

I would be paying $1,181 with the trade assurance fee, plus the credit card transaction fee for 8 cells, x2 if I decide to build both 24v cells at one time. Appreciate any advice...

 

[SparkyJJO]

The LF280K cells have a reputation of not always hitting 280Ah. Seems more often than not they are a little below that. Maybe a bum manufacturing process, or something else, but it appears you'll rarely see the 280K pull 280Ah.

 

[sunshine_eggo]

I have been communicating with a rep for a company that seems to be reputable on this forum and in some YouTube videos. After getting many questions answered I was feeling very comfortable and just had two final questions before ordering. One question was just clarifying the cost difference between purchasing stock from overseas vs out of their US warehouse which has the supply of cells and BMS that I would like. The other question and the reason for posting here follows (note that the order will be for 8 (possibly 16) Eve LF280K cells:

Question: Last question (I think)…if the cells do not test at 280ah, would I be working with you to resolve?
Response: The capacity might be around 270-280ah. It is normal.

This will be my first foray into building my own batteries. In all my research, I thought new good quality cells will have a minimum of the stated Ah capacity (typically more than the stated capacity) and anything below the stated capacity suggests sub-par or used cells. Is my understanding correct or misguided?

I would be paying $1,181 with the trade assurance fee, plus the credit card transaction fee for 8 cells, x2 if I decide to build both 24v cells at one time. Appreciate any advice...

All cells purchased through these means do not meet the manufacturer's full specification. Full spec cells are not sold outside the EV market. Failing to meet capacity is pretty common. The 270-280Ah claim is typical. My 9 EVE cells mostly fit this with capacities ranging from 264-278.

Always buy an extra cell or two.

 

[riverbug]

Thanks for the responses. I had previously searched for threads on these batteries and the supplier and mainly found positive information, but now that I posted my question I'm seeing "similar threads" being suggested that show this does appear to be a common issue. From what I can tell it doesn't seem to turn people away from purchasing them and I guess as long as the cells last for many cycles as advertised and hold their capacity I shouldn't be too concerned either.

 

[sunshine_eggo]

When you get 95%+ of the goody for 50% of the price, it certainly feels like a good deal.

The longevity is always a question, but there have been enough folks running 3+ years to give some confidence.

 

[riverbug]

When you get 95%+ of the goody for 50% of the price, it certainly feels like a good deal.

The longevity is always a question, but there have been enough folks running 3+ years to give some confidence.

That makes sense now. I just hadn't realized the difference in "new grade A" cells as advertised vs what you are getting. But for the price it's hard to argue that they may not be perfect. It'll be a fun project either way and if they last many years it would be icing on the cake. Thanks.

 

[John Frum]

That makes sense now. I just hadn't realized the difference in "new grade A" cells as advertised vs what you are getting. But for the price it's hard to argue that they may not be perfect. It'll be a fun project either way and if they last many years it would be icing on the cake. Thanks.

Were the advertised as new grade A?
Do they come with test certification?

 

[riverbug]

Were the advertised as new grade A?
Do they come with test certification?

Well now that you ask, clearly what I was looking at on their website is not what the rep was selling me. I'm just starting to put 2 and 2 together now. When I emailed her, I stated I wanted "new grade A cells and looks like LF280K would be a good match", based on what I was reading here: https://www.docanpower.com/index.php?route=product/product&search=280K&product_id=497&search=280K
but not realizing until just now that there are several variations to the LF280K. So, thanks for asking that. Now I can at least go back to her and ask specifically about the cells in the link.

 

[Alkaline]

Why are you messing around with the 280K don't you know this is BS cell eve made that doesn't meet capacity or barely meets it even with test reports?

Grade A 280k = Barely 280AH usually 276 ish but it will meet WH of around 900
Grade B 280k = In the mid 260AH and WH is in the low 830, some as low as 795

There are far better options out there, like grade B REPT cells from 18650store.

If you want cells with test reports and intact QR codes then you need to buy grade A and demand a copy of the test report that lists each cell and its test data.

But you not getting those for $140 or a cell, those will be near $190-$220 / cell

 

[sunshine_eggo]

Here we go again.

 

[riverbug]

Why are you messing around with the 280K don't you know this is BS cell eve made that doesn't meet capacity or barely meets it even with test reports?

Grade A 280k = Barely 280AH usually 276 ish but it will meet WH of around 900
Grade B 280k = In the mid 260AH and WH is in the low 830, some as low as 795

There are far better options out there, like grade B REPT cells from 18650store.

If you want cells with test reports and intact QR codes then you need to buy grade A and demand a copy of the test report that lists each cell and its test data.

But you not getting those for $140 or a cell, those will be near $190-$220 / cell

But the cells at the link states new grade a+ with test report included. Being new to this how would I know that it's not true? And states 285-290Ah.

 

[Alkaline]

I have been communicating with a rep for a company that seems to be reputable on this forum and in some YouTube videos. After getting many questions answered I was feeling very comfortable and just had two final questions before ordering. One question was just clarifying the cost difference between purchasing stock from overseas vs out of their US warehouse which has the supply of cells and BMS that I would like. The other question and the reason for posting here follows (note that the order will be for 8 (possibly 16) Eve LF280K cells:

Question: Last question (I think)…if the cells do not test at 280ah, would I be working with you to resolve?
Response: The capacity might be around 270-280ah. It is normal.

This will be my first foray into building my own batteries. In all my research, I thought new good quality cells will have a minimum of the stated Ah capacity (typically more than the stated capacity) and anything below the stated capacity suggests sub-par or used cells. Is my understanding correct or misguided?

I would be paying $1,181 with the trade assurance fee, plus the credit card transaction fee for 8 cells, x2 if I decide to build both 24v cells at one time. Appreciate any advice...

go look on this site: https://www.18650batterystore.com/collections/lifepo4-prismatic-cells

Now go to this product: https://www.18650batterystore.com/products/eve-lf105

Do you see that green / yellow spread sheet? That is what a grade A cell is, it comes with a test report. Those are the ones that will meet your requirements, but you are going to pay more.

90% of the forum users prefer "TESTED GRADE B" where the supplier of the grade B does there own test and sorts them, but understand the grade B failed manufacturer testing for whatever reason could be quality, capacity, or some bs cosmetic reason... But we can get them at a good discount.


You have to decide how important this is to you, if you are the type of person that only the best will do then you need grade A with test report. But you are a bit scrappy, decent grade B can be an option.


I'm assuming you are in the US so its best you buy locally so you can return if you are unhappy, no possibility of returning if you are buying from China direct, but you will get better pricing from China direct though.

 

[riverbug]

go look on this site: https://www.18650batterystore.com/collections/lifepo4-prismatic-cells

Now go to this product: https://www.18650batterystore.com/products/eve-lf105

Do you see that green / yellow spread sheet? That is what a grade A cell is, it comes with a test report. Those are the ones that will meet your requirements, but you are going to pay more.

90% of the forum users prefer "TESTED GRADE B" where the supplier of the grade B does there own test and sorts them, but understand the grade B failed manufacturer testing for whatever reason could be quality, capacity, or some bs cosmetic reason... But we can get them at a good discount.


You have to decide how important this is to you, if you are the type of person that only the best will do then you need grade A with test report. But you are a bit scrappy, decent grade B can be an option.


I'm assuming you are in the US so its best you buy locally so you can return if you are unhappy, no possibility of returning if you are buying from China direct, but you will get better pricing from China direct though.

In all my research over the past several months I never came across 18650. It seems to me this would be a no-brainer based on their website. They state new grade A cells with report (upon request), matching voltage capacity and internal resistance, with 30 day money back guarantee and 1 year warranty, and based in-country (US). And the price difference for 8 cells with all fees (shipping, taxes, etc.) is $118 more than what I have been quoted from Docan. Now assuming everything stated about the cells is true, then I'm also getting cells that will meet or exceed the rated capacity vs the somewhat misleading experience I am having with Docan about the same cells right now.

So why all over YouTube and this forum do you only hear about ordering from China and all that entails? Is this too good to be true?

 

[Zwy]

In the past I ordered from China, specifically from Amy Wan at Shenzhen Luyuan and she is a great seller from China. I purchased 48 cells from her. Recently I wanted to add 16 more cells, 304Ah cells, Grade B. I looked at prices thru Amy, Docan and 18650 plus some others.

The price difference was minimal between shipping from China or US, maybe $200USD at the most on 16 cells. Docan has changed the price 5 times in messaging. How about the best price the first time? And if I have trouble with a cell, what about shipping or warranty?

I decided it isn't worth the hassle of dealing with an overseas seller as the savings might be less than 10% difference. I ordered the Grade B 304Ah from 18650. They arrived in 4 days, look great. I will be assembling them soon in 12V packs for top balancing and testing. I doubt there will be a problem.

 

[timselectric]

My LF280k cells from 18650batterystore all tested over 285. You get what you pay for.
Ignore the A and B grading. It's just marketing hype.
Just look at what people here are saying about what and where they buy cells. Find what gives you what you want for the price you want to pay. As long as you don't see really bad reviews here, you'll be fine with whatever you choose.

 

[John Frum]

Well now that you ask, clearly what I was looking at on their website is not what the rep was selling me. I'm just starting to put 2 and 2 together now. When I emailed her, I stated I wanted "new grade A cells and looks like LF280K would be a good match", based on what I was reading here: https://www.docanpower.com/index.php?route=product/product&search=280K&product_id=497&search=280K
but not realizing until just now that there are several variations to the LF280K. So, thanks for asking that. Now I can at least go back to her and ask specifically about the cells in the link.

Its not clear from your explanation, what did you order and what did you pay for?

 

[riverbug]

Its not clear from your explanation, what did you order and what did you pay for?

I didn't order or pay for anything yet. The reason for starting this thread was to get feedback so I could understand things better and make a decision on whether or not to place an order. Now that I understand everything better, I realize that what I thought I was being quoted for were cells certified at 285-290Ah but the quote was for cells that are not certified but promise 270-280Ah. And now after being made aware of 18650, I have another option to consider purchasing from.

 

[John Frum]

I didn't order or pay for anything yet. The reason for starting this thread was to get feedback so I could understand things better and make a decision on whether or not to place an order. Now that I understand everything better, I realize that what I thought I was being quoted for were cells certified at 285-290Ah but the quote was for cells that are not certified but promise 270-280Ah. And now after being made aware of 18650, I have another option to consider purchasing from.

Glad you stopped by before you pulled the trigger.
Wish more people would follow your example.

 

[riverbug]

Glad you stopped by before you pulled the trigger.
Wish more people would follow your example.

Hey thanks, but if it weren't for the helpful people on this forum I really wouldn't have been the wiser. It wouldn't have been a catastrophic mistake by any means but I would have been disappointed and maybe felt a little embarrassed once I realized I bought something that didn't match my expectations. It's pretty confusing for a newbie trying to decipher the variety of cells. Live and learn...

 

[Alkaline]

In all my research over the past several months I never came across 18650. It seems to me this would be a no-brainer based on their website. They state new grade A cells with report (upon request), matching voltage capacity and internal resistance, with 30 day money back guarantee and 1 year warranty, and based in-country (US). And the price difference for 8 cells with all fees (shipping, taxes, etc.) is $118 more than what I have been quoted from Docan. Now assuming everything stated about the cells is true, then I'm also getting cells that will meet or exceed the rated capacity vs the somewhat misleading experience I am having with Docan about the same cells right now.

So why all over YouTube and this forum do you only hear about ordering from China and all that entails? Is this too good to be true?

Cause that is how we all started before there were USA vendors. But now I think its game over for them and the word is getting out between grade A and grade B.

Good that you came on the forum and asked.

Don't be hard on yourself, at least you are not a Moron like me who decided to be cheap and buy a Sungold 6548 that apparently has a garbage out put and rocky mountain style sine wave... I knew I shouldn't have ordered it...