LiFePO4 in 18650 format?

jonescg

jonescg

100 MW
Joined
Aug 7, 2009
Messages
4,224
Location
Perth, Western Australia
Can anyone suggest a half decent LiFePO4 cell in 18650 format? I think A123 were making them at one point, but not sure where that went. Also, does Samsung even make LFP chemistry cells? I suspect there are some Chinese heat-shrinking companies out there....

Thanks in advance.

Chris
 
I've seen a bunch of places that sell packs built of them, but none of the ones I've actually worked on had decent ones; no idea who actually made the cells.

There's probably *somebody* that makes good ones......

I think I had *one* A123 18650 Methods had sent me with some ohter stuff, but I nevver got to test it; it was stolen with a bunch of other stuff after the housefire. :/

Here's what google shows for Samsung on the subject...not much

https://www.google.com/search?num=100&newwindow=1&q=samsung+18650+%22lifepo4%22&sa=X&ved=2ahUKEwiyg5__5ZHdAhVk04MKHdUlC1sQ5t4CMAp6BAhiEAg&biw=989&bih=767
 
jonescg said:
Can anyone suggest a half decent LiFePO4 cell in 18650 format? I think A123 were making them at one point, but not sure where that went. Also, does Samsung even make LFP chemistry cells? I suspect there are some Chinese heat-shrinking companies out there....

Thanks in advance.

Chris
Click to expand...

Hello,

I've read somewhere that this brand is reliable.

https://www.nkon.nl/rechargeable/18650-size/heter-enerpower-18650-lifepo4-1100mah.html

https://www.nkon.nl/rechargeable/18650-size/heter-18650-1800mah-5-4a.html

They have different kind of cells, they've started to be popular in Europe.
 
amberwolf said:
Here's what google shows for Samsung on the subject...not much
.
Click to expand...

I wrote to Samsung Asia-Pacific and Samsung Korea and for this response:

"Hello
Thank you for your interest of Samsung SDI.
FYI, We don't produce LFP battery.
Best regards

이대의
<delee@samsung.com>"
 
A123, 1.1Ah 60C, LFP 18650, still available.....
..at a price ! :shock:
https://www.ebay.com.au/i/252985007571?chn=ps

OR .. if you want the ultimate..
http://www.ebaracus.com/product/a123-ahr18700-f1-kers-cells
AHR18700M1-Ultra-F1-Image.png
 
Why would you use lfo? Regular 18650's is superior in almost every way.
 
Jonesy..
Depending on what you are looking for.... Check your local Bunnings.
I just noticed they had a stack of "Energiser" 18650 (and 18500?) , 1.1Ah , LFP cells they were selling off for $2.50 a pair. In the garden solar lights section.
They are used in the solar lights, so i doubt they are much use for any power application.
FYI they also have AA size and NmHi in both sizes too.
 
I'll have a look.
My work has asked me to source some cells for an underground mining application. They have explicitly asked for LFP chemistry for safety reasons. Why 18650 format? Well that's the hill we've decided to die on apparently so that format will have to do.

I still think NMC or LCO are fine if treated nicely, but that's what they want.
 
flippy said:
Why would you use lfo? Regular 18650's is superior in almost every way.
Click to expand...

Except when it comes to cycle and shelf life.
This is where LifePo4 shines.
My wifes old 24V 10ah LFP pack for her bike is still going strong after almost 8 years with daily rides between 60-90% DoD each way when going to work.
It has probably passed 3000 cycles by now.
I would like to see any modern cell handle that and still be strong and efficient.
 
Honk said:
flippy said:
Why would you use lfo? Regular 18650's is superior in almost every way.
Click to expand...

Except when it comes to cycle and shelf life.
This is where LifePo4 shines.
My wifes old 24V 10ah LFP pack for her bike is still going strong after almost 8 years with daily rides between 60-90% DoD each way when going to work.
It has probably passed 3000 cycles by now.
I would like to see any modern cell handle that and still be strong and efficient.
Click to expand...
If you charge to 4.05v you can get 8000 cycles easy if you have the right size battery.
 
Easy you say?
Proof or it didn't happen!
 
Proof I have a 5yr old pack with 18yr old cells A123 20ah 1,209 cycles at 80 amps good as new almost a little capacity lost. Melted 4 Motors and two controllers and 3 sets sense wires for checking voltage no bms. Just bulk charge as my balance charger only gets used for curiosity. Just a big heavy pack. LTO is also big and heavy plus low voltage.
Honk make flippy prove it.
 
Honk said:
Easy you say?
Proof or it didn't happen!
Click to expand...


I got a 16S25P pack here used 6 days a week for about 4 years now (that is already 1250 cycles) and i lost about 6% capacity. And no, this pack was not treated well but was usually charged to 4.05v in summer and 4.1v in winter.
Do the math and you get 5000+ cycles before this pack is under 70% remaining capacity wich still means i can drive 50 miles with a "worn" pack.
If this pack was better cared for (it drove more then a year without a bms or balancing of any kind) and not abused with 300A peaks then it would live a lot longer.


I am also running cycle testing on a bunch of cells on dedicated hardware with the same useage cycle as you would get on a 30mph moped wich is slowly starting to show results.
 
Honk said:
flippy said:
Why would you use lfo? Regular 18650's is superior in almost every way.
Click to expand...

Except when it comes to cycle and shelf life.
This is where LifePo4 shines.
My wifes old 24V 10ah LFP pack for her bike is still going strong after almost 8 years with daily rides between 60-90% DoD each way when going to work.
It has probably passed 3000 cycles by now.
I would like to see any modern cell handle that and still be strong and efficient.
Click to expand...

I agree with you 100%. All my lithium packs started to sag a lot after 1.5-2 years of daily use and finally had to replace them in order to have maximum performance - capacity.

If you compare them with the chemistry you are talking about there is no comparison in cycle life.

Of course IF you have a huge lithium pack, IF you charge it only up to 4.1 volts only, IF you don't abuse it by not drawing more than 50% of the maximum current according to cell specs then the pack can live for five years or more.

BUT there is not always big space for a such huge pack also its heavy & expensive for some ebikers so the result is the most of lithium packs lose performance - capacity very rapidly compare to your wife's battery.
 
LFP/O takes up a lot more space and weight then a simmilair sized lipo, so why stick to having a big , heavy pack with 50miles of range when you can fill the same space amd weight with a battery that will live just as long and give 100miles of range for basically the same cost. Or reduce the size and weight and cost for a small reduction in possible lifespan...

Honest question here, sometimes the reasoning for choosing LFP/O is completly passing over my head.

I understand LFP/O has its place, just not on bikes and other applications were weight and size are serious constraints.
 
999zip999 said:
Proof I have a 5yr old pack with 18yr old cells A123 20ah 1,209 cycles at 80 amps good as new almost a little capacity lost.
Click to expand...

That's no proof as the A123 is LFP, proven sturdy and longlife, just as my wifes LFP pack.
I refered to NCA, NCM, and similar 4.2V 18650 chemistries being less capable in the long run.
But perhaps I'm wrong and you can get extreme cycle life with sag when pussy handling the cells.
 
you dont have to handle to handle them like a pussy, just charge them slow and not higher then 4.05V and you will have a happy, productive battery.

parial charging is almost impossible with LFP/O cells as the curve is almost flat so SOC calcualations based on voltage is almost impossible. that kinda sucks unless you use coloumb based meters.

LFO/P might have a seductive advantage in lifespan, but that does not save it from its many drawbacks.
 
flippy said:
you dont have to handle to handle them like a pussy, just charge them slow and not higher then 4.05V
Click to expand...

Great. But isn't slow and gentle charging kind of coddling the pack.
I wonder what cycle density one could get out of LFP if charging them similarly...
How about the sag issue of LFP vs 4.2V chemistries ?
 
Honk said:
flippy said:
you dont have to handle to handle them like a pussy, just charge them slow and not higher then 4.05V
Click to expand...

Great. But isn't slow and gentle charging kind of coddling the pack.
I wonder what cycle density one could get out of LFP if charging them similarly...
How about the sag issue of LFP vs 4.2V chemistries ?
Click to expand...
Why not charge slow? There is no need to charge in 1 hour exept for edge cases or if you made some realy poor sized pack. A 4~8h charge is something almost anyone can do.

What sag issue? A lipo pack that is physically the same size as a LFP pack will kick its ass on all performance metrics.
And if voltage sag is a issue then you built your pack wrong.

Dont blame the chemestry for poor pack building choices.
 
It like comparing apples and oranges when comparing standard charging vs slow charging.
Initial post was about my wifes standard charged LFP that's still going strong after 8 years.
Not much sign of either cycle damage or shelf life detoriation.
In similar conditions not many 4.2V chemistries is equally durable.

Don't get me wrong. I like the NCM 29E and is building several 1kW packs right now for my outboard.
Just to threat them well I will use slow charge rate at 0.2C until 4.1V max.
They will also be stored cold at 50% SoC between rides.
By pussy coddling them this way I expect very long life time, perhaps up to 20 years.... time will tell.
 
I think LFP also can kick ass in terms of current drain.

The LFP 18650 sized A123 can give 60 AMPS per cell !!!?!
Now I've never seen any other chemistry in 18650 sized format than are rated for more than 35 amps max !

The LFP is the NiCad of lithium chemisty in terms of amps draw and low internal resistance...
 
Honk said:
Don't get me wrong. I like the NCM 29E and is building several 1kW packs right now for my outboard.
Click to expand...

Don't get me wrong but Samsung INR18650-29E is based on NCA chemistry like many others cells in 18650 Samsung production line. For example 30Q, 25R, 48G and others...
 
You must log in or register to reply here.

Similar threads

L
Which are the worst cells in the format: 18650, 20650 and 21700 that you have encountered?
Replies
3
Views
427
leffex
L
O
Lifepo4 cylinder 32650 cells simplified stationary design idea?
Replies
7
Views
153
jonescg
jonescg
I
What to do with these used 18650 Ni-MH ?
Replies
5
Views
387
amberwolf
amberwolf
M
Help with first pack build
Replies
10
Views
483
mynameisjoe
M
Skyler
LFP reverse polarity.
2 3 4 5
Replies
105
Views
4,524
DaLanMan
DaLanMan
Back
Top