headway H-38120HP Headway LiFePO4 Cell

[nechaus]

Has anyone tested these cells ??

H-38120HP Headway LiFePO4 Cell
SPECIAL ORDER ONLY The 38120HP (8Ah) LiFePO4 cell is an excellent choice for your high discharging power needs. Capable of up to 25C (200A) of discharge and up to 10C (80A) of charging.
$23.75

http://stores.headway-headquarters.com/-strse-BATTERIES/Categories.bok


Was going to get some a123's which i think is still better, but having 25 c with these would be ideal for me, I can see the tabs on the 20 ah a123 cells will be a problem and time consuming for me. Have found headways to be the easiest to assembly for my ebikes + easy to replace cells if i need to.

$1120 for 48 cells not including shipping
24s 2 p lifep04
About 16 kg for battery pack and about 1.1 kwh +
They also have a 24 s BMS, with a nice discharge.

 

[neptronix]

I'll tell you right now...

Headway discharge specs, historically have been very overrated..
The packs come out at about the size of SLA equivalent, maybe even bigger.
And they weight a ton, literally having the worst energy density of any lithium cell i can think of.. ( 80-100wHr/KG ).
A123 is drastically lighter and smaller. RC Lipo, NMC, etc are even lighter than that.. ( and way smaller )

I have not tested the high power type cells, but the cells i did test that were advertised as 10C capable, got really really hot and saggy at 3C..

If you must go with lifepo4 and high discharge is a priority, stick to A123.

Also you need to figure out how to mount this to your bike. The pack is going to be extremely large and heavy.
There is a reason why most people on this forum have abandoned headway cells entirely.

 

[nechaus]

I would get the a123's 15ah or 20ah cells but i fear that ill break the tabs and have useless cells
I was thinking of some kind of way to clamp the tabs. no solder, no welding, just using copper bars + nuts and bolts?

 

[bigmoose]

nechaus search this site for A123 tab attachment methods. You will find many discussed from spot welding, to pinch rolling, to machined clamps. I believe there is a 20AH pouch pack up for sale at this time also. The gent has pictures of his PCB and metallic connectors on that thread. Good luck!

 

[neptronix]

I don't know anyone who sells legit 15AH/20AH A123 cells.. but if you do, right on!

http://emissions-free.com/catalog/c2_p1.html

Cell_man makes packs made out of the 2.3ah ( i think? ) cells.. hand assembled by him and company.
A cell_man pack won't be too much more spendy than your headways pack ( once you consider all the construction needs, BMS etc.. you can also get an 80A BMS from him.

Just 1 option of many, but you may want to consider sending him an email asking him if he can do a 72V pack for ya and what it would cost.

Wish we had better cells available to us. Everything is a compromise.

 

[cell_man]

Thanks Neptronix

I also supply packs made from A123 20Ah pouch cells. Here is a couple of pics of a 12S 20Ah Pack including BMS with insulation and mechanical protection (about 10% of the weight is BMS and packing/assembly materials):





Packs are only built from cells with low self discharge and packs are discharge tested. They all come out to approx 20Ah or even a little over.

A 24S 20Ah will be a little over 13kg, has almost 1.6KWhrs. Price is very similar to that 1.1KWhr headway pack and mine comes ready to plug in, tested and balanced, you don't have to built it yourself. Shipping from China will be a bit more of course.

 

[neptronix]

I didn't know you had access to the 20AH cells!

Are your 20AH premade packs a bit cheaper per amp hour than the cylindricals, btw?

 

[nechaus]

how are the cells connected when using the 20 ah cells ?
soldered
spot welded
crimping..
how is it done

 

[nechaus]

I don't know anyone who sells legit 15AH/20AH A123 cells.. but if you do, right on!

http://emissions-free.com/catalog/c2_p1.html

Cell_man makes packs made out of the 2.3ah ( i think? ) cells.. hand assembled by him and company.
A cell_man pack won't be too much more spendy than your headways pack ( once you consider all the construction needs, BMS etc.. you can also get an 80A BMS from him.

Just 1 option of many, but you may want to consider sending him an email asking him if he can do a 72V pack for ya and what it would cost.

Wish we had better cells available to us. Everything is a compromise.

they seem cheap from a123rc.com

 

[neptronix]

Might want to check reports from other users on ES before buying from a company like that.

Lots of fake/reject A123 cells out there being sold by Chinese companies these days.

http://endless-sphere.com/forums/viewtopic.php?f=14&t=33939&hilit=a123rc
http://www.diyelectriccar.com/forum...6427087648bf1b07b32f1b1a6b0a42&t=66700&page=5

The 'made in USA' label seems incorrect as well. I don't believe A123 cells were ever made in the USA.
~$39 seems a bit too cheap for these if they were genuine.

It's up to you if you want to take the risk to save some money. I hunted around ES and did not find any indications that the cells from A123RC are genuine.

 

[nechaus]

awww man, I thought i read somewhere they were real...
that really sucks..

but thanks for pointing that out neptronix, going to call my friend and tell him to not order anynow!!

 

[neptronix]

awww man, I thought i read somewhere they were real...
that really sucks..

but thanks for pointing that out neptronix, going to call my friend and tell him to not order anynow!!

Well, don't take my word for it 100%, do your research for sure.
A lot of people have been burned on fake 20AH A123's though. So if you see uber cheap A123 20AH, i would be a little skeptical to start out

I take it you haven't been burned by a China battery seller yet and earned yourself a nice dose of skepticism

 

[nechaus]

haha yeah, when i first found alibaba and aliexpress i thought it was great.
but after buying so called A grade solar cells and a grade batteries
i got solar cells that were chipped, batteries voltages lower than some cheap meters would even read.

99% its all rejected and little Chinese men setting up websites and accounts with trade sites selling their rejected goods.
I once had to make a paypal claim on a guest account, it took so long.
I remember this email, this guy telling me he earns less than 50usd per month @ the factory and he needs to have a business on the side to feed his family.

Tried to get some "Body building supplements" from tradekey.com once, even got scammed about 1k about 2 years ago.. stupid western union, that one was my own fault tho. To dam trusting some times.

 

[neptronix]

Well, glad i could save you some $.
Batteries are definitely a big scam for these Chinese vendors.

I know you have not been on here long, so I'll tell you this though about batteries from what i've seen:

+ Headway cells are legit and i've not heard of any fakes going around.
+ RC Lipo has about a 10%-15% Dud rate from hobbyking, IE one cell will be bad here and there out of so many packs..
+ It isn't hard to find legit A123 2.3AH 26650's, but there are some fakes out there.
+ Going off heresay, it seems like well over 75% the China vendors selling 20AH A123 sell used/rejected cells. These are highly coveted/desired but A123 refuses to sell them to the public, so if you DO find legit ones, only god knows how the vendor got them!
+ Cell_man is a really reputable vendor on here, i don't know how he gets his 20AH A123 cells, but i do know that he tests them, and doesn't send out junk. Same goes for his 26650 packs.
+ Ping is rock solid as a vendor could possibly be and the ping packs generally live up to their discharge rate.

 

[dnmun]

those A123 cells are real. the ones labeled made in the US were manufactured at the a123 plant in livonia, michigan. JD had a video of the plant on the other thread where people pretend to know they are fake.

 

[nechaus]

why do people pretend to know they are fake? and they are not fake
they want all the damm cells, and there will be none left for me..

id take a good fake/reject, but id want them to be exactly the same ah or pretty damm close + last 1000's of cycles
from what i understand they don't even sell them to small business's ??

 

[neptronix]

A123 has never sold to anything other than a giant corp, so all cells have pretty much magically appeared in vendor's hands.. lol.

I'd like to see this vid dnmun; the majority of threads i've seen have people calling them fake.

Believe who you want, i've just hared of tons of people getting burned throughout the years on these cells. Order 1 or 2 if you must, have the proper testing equipment handy ( even an upper level RC charger will do ), and see for your self if they are even remotely new or just total rejects.

 

[nechaus]

i don't think im going to even bother tho, takes me a lot of time to build a good battery pack, i would not want to build one, and have a cell fail couple of hundred cycles, while expecting to get 1000 +

i do like getting stuff new