Again, how to make sense of lifepo4 quality grading based on price? What is grade A B…

[Off-grid lifestyle]

I have contacted more than 50 suppliers in china for what they call “grade A” lifepo4 cells but I am
More confused then ever, the discrepancy of information I have gathered made my PhD in economics journey looks so easy!!

When things don’t make sense to me, it means that either I am not well informed about the subject matter or the information itself is chaotic by nature.

I have received price quotes around 3,000$ for a 5kw battery pack with 10 years warranty from 3 reputable companies

Also received around 1,500$ Quote for the same battery with 5 years warranty from 2 other reputable companies.

I have received price quotes bellow 1,000$ from more than 20 other not-so-well-known suppliers with 10 years warranty.

I have received the similar price quote with 20 years warranty from few suppliers!

And the individual cells to form a 5 kw battery could cost anything between 500 to +1000$ with BMS, that is more than 20 suppliers.

In economics, prices should reflect all available information about the product. But that is only applicable in an efficient market where information are quickly transmitted among players.

If the prices I have seen are reflective of an efficient market, it means that there is at least 3 categories/quality of lifepo4 cells. The super VIP quality that last for +20years, the good quality that last for +10 years, and the not so good quality that I don’t know how long it will operate( recycled, defective ..) The warranty provided by the top reputable companies are mostly what I have made my analysis on as they have a lot to lose if things went bad. The warranty provided by the not-so-well-know companies are unreliable, not to go with the details…

On one hand, it does not make sense to pay +3000$ for a battery that last for +20 years knowing that 7 or 10 years from now technology might change for better, on the other hand it very risky to gamble with a 800$ on a battery that could Last less than lead acid. (Just to make a point here, Personally I am looking for a DIY +30 kw bank and +100kw banks for my brothers and friends )

But I am not a player in that market and that is why I am posting this thread.

In my opinion, the only way to clarify this obscurity is to have members that have bought cells or pre-assembled pack 2 or more years ago to share their experience. Information on price paid, warranty granted, reputation of the supplier, and more importantly how long the pack has been in operation without problems- how many cycles have the pack done and capacity lost, personal opinion about the pack quality, would clarify a lot of information for myself including forum members regarding the expected quality of lifepo4 batteries given a certain Price.

This post is trying to find answers from experienced members only on how many cycles we could expect from these cells.

If a cells is advertised for 3000 cycles on the manufacturer datasheet, and priced within the “good quality” category, would it make +1,500 cycles? Can we expect at least half?

What if it was priced within the “not so good quality” price range? Would it pass the 1,000 cycle mark?

 

[robby]

I have contacted more than 50 suppliers in china for what they call “grade A” lifepo4 cells but I am
More confused then ever, the discrepancy of information I have gathered made my PhD in economics journey looks so easy!!

When things don’t make sense to me, it means that either I am not well informed about the subject matter or the information itself is chaotic by nature.

Most of the Vendors are lying. They are typically going to be Grade B cells but the question is what kind of condition are the Grade B cells in. Some are used cells that are cleaned up and others are rejects from the factory after the one month testing process. There is like 5 main reasons why a new Cell will be rejected and reclassified as Grade B.

I have received price quotes around 3,000$ for a 5kw battery pack with 10 years warranty from 3 reputable companies

If you list the companies you will probably get some better feedback on their reputation.

Also received around 1,500$ Quote for the same battery with 5 years warranty from 2 other reputable companies.

I have received price quotes bellow 1,000$ from more than 20 other not-so-well-known suppliers with 10 years warranty.

I have received the similar price quote with 20 years warranty from few suppliers!

Everyone is trying to make a buck so you if you have the money and really want to make sure you get Grade A cells then deal with one of the big expensive brands like BYD, Simpliphi, Fortress or any of the other major brands.

And the individual cells to form a 5 kw battery could cost anything between 500 to +1000$ with BMS, that is more than 20 suppliers.

In economics, prices should reflect all available information about the product. But that is only applicable in an efficient market where information are quickly transmitted among players.

If the prices I have seen are reflective of an efficient market, it means that there is at least 3 categories/quality of lifepo4 cells. The super VIP quality that last for +20years, the good quality that last for +10 years, and the not so good quality that I don’t know how long it will operate( recycled, defective ..) The warranty provided by the top reputable companies are mostly what I have made my analysis on as they have a lot to lose if things went bad. The warranty provided by the not-so-well-know companies are unreliable, not to go with the details…

There is A, B and C grade batteries. They also claim some are A+. The C grade are usually recycled or dumped.

On one hand, it does not make sense to pay +3000$ for a battery that last for +20 years knowing that 7 or 10 years from now technology might change for better, on the other hand it very risky to gamble with a 800$ on a battery that could Last less than lead acid. (Just to make a point here, Personally I am looking for a DIY +30 kw bank and +100kw banks for my brothers and friends )

Technology changing does not matter all that much. If your batteries are still holding a good charge 10 years from now, why would you change them. If something that works ten times better comes along and you really want more power you can always add it to your existing system and use a separate charge controller.

But I am not a player in that market and that is why I am posting this thread.

In my opinion, the only way to clarify this obscurity is to have members that have bought cells or pre-assembled pack 2 or more years ago to share their experience. Information on price paid, warranty granted, reputation of the supplier, and more importantly how long the pack has been in operation without problems- how many cycles have the pack done and capacity lost, personal opinion about the pack quality, would clarify a lot of information for myself including forum members regarding the expected quality of lifepo4 batteries given a certain Price.

There are one or two member on here who have Lithium Iron battery banks that are 10 years old and they say they are still working perfectly, minus the expected loses with age.

This post is trying to find answers from experienced members only on how many cycles we could expect from these cells.

If a cells is advertised for 3000 cycles on the manufacturer datasheet, and priced within the “good quality” category, would it make +1,500 cycles? Can we expect at least half?

If they are good quality the cycle life for Iron Phosphate batteries should be around 6000 cycles.
If your being told 3000 then they are probably not Grade A batteries. It is highly likely that a 3000 cycle rated battery will give you 3000 cycles but that depends on the battery.

What if it was priced within the “not so good quality” price range? Would it pass the 1,000 cycle mark?

Most likely it would but if they are cycled daily that is less than 3 years of life. Also any LIfePO4 battery that had a 1000 cycle life guarantee is probably really used up or it might be a Grade C cell that got purchased in the grey market.

Your confused because it is confusing. About 20% of the threads on here deal with people trying to find out which battery to buy and which ones not to buy. It's easy to know if you go with the expensive brand name packs but the waters are really murky when dealing with battery suppliers from China. From remarks I have read you do have some very reputable distributors on the forum that import batteries from China. Just look around and you will see some threads that involved very good sellers.

 

[Loadtoad]

Warranty? Forget about sending them back if there is a problem. If I bought from China I would not put stock in any warranty claims. Those vendors come and go there, I don't think the outfit you bought from will be there in 10 years.

 

[Bob B]

So ... What is your goal? To get the best pack / cells available .... or get something that will work?

The only way to guarantee either one of those things is to find a supplier that others on here have rated as highly reliable .... over a long period of time.

The warranty is worthless if you have a bad provider .... they will demand that you return the item to China ... or just claim that things are all your fault.
As a rule of thumb ... the ones selling what seem to be the same cells at a much cheaper price are very likely to be poor quality cells or even an outright scam.