# headway cells



## mizlplix (May 1, 2011)

They are good cells. I have some in a small application.

Although I have known people to assemble many into an EV pack, it becomes quite expensive.

Miz


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## ricklearned (Mar 3, 2012)

I have also used them. I have two 36 volt packs on two bicycle conversions I have done over the past two years. They are good cells for that application and are easy to configure into pack sizes to fit two different bike frames. One is a triangle pack in front of and below the seat and the other is a rectangle pack on a rack over the rear wheel. I am considering them for a VW conversion/build but I haven't been able to find a price that is competitive with the $/whr of the prismatics on a scale of KW that I would need for the VW.


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## crashedup (Oct 28, 2008)

There isnt a huge price differance in the headway and say other prismic cells like thundersky etc. headway works out to $1.50/ah and around $1.20 for the others. And headway is the only battery that ive seen thats available that can peak discharge at 10c.
for a fast ev conversion I think headway is the only way to go!


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## frodus (Apr 12, 2008)

I've got almost 200 of them, all going in my motorcycle and most of them have been tested at 5-10C and perform just fine for my needs. They have a higher C-rate, are available readily and they're great cells. While not as easy to package as the prismatics, they're very versatile and you can shape them easily.

Here's a mockup of what I'm working on now, a 32s5p pack:










Not the final shape or design, but it's an example of a headway pack.


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## Yabert (Feb 7, 2010)

crashedup said:


> they seem to be the best on the market at this moment.


Good, but not best. 
I have a good experiment with headway cells. I think you missed this and my build threads.

There have some types of headway cells. Most powerful is 38120HP (8Ah) who can discharge at 20-25C. With an impedance of 3 mohm or less, they are rated at over 1500w per Kg. 
Good cells for high performance..., but not for high performance and range of 65 miles. The price and the energy density (weigh) is too bad to justify large pack.


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## frodus (Apr 12, 2008)

Yeah, they're not the most dense cells out there, but they're a good bang for the buck IMHO. 

They're mid-level batteries. Not the best, but better than others.


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## crashedup (Oct 28, 2008)

What are the best cells available for us normal people on the market then? 
A123 looks great but from what i could understand we cant buy them yet!
If we can please let me know where?


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## rwaudio (May 22, 2008)

crashedup said:


> What are the best cells available for us normal people on the market then?
> A123 looks great but from what i could understand we cant buy them yet!
> If we can please let me know where?


You can buy what are regarded as grey market A123 cells. They might be legit, they might be rejects they might be who knows what. But they can be had from china for a decent price and they perform very well. They aren't the easiest to make into a pack though. All things considered, I wouldn't choose any other cell for my car!


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## Brute Force (Aug 28, 2010)

Currently, the only legitimate outlet for A123 cells is:

www.mavizen.com

Be prepared for some sticker shock. And A123 is a little behind trying to get their recall fiasco resolved.


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## crashedup (Oct 28, 2008)

Could i have the link for those gray market china made ones?


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## frodus (Apr 12, 2008)

victpower

look it up on alibaba and contact them.


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## steven4601 (Nov 11, 2010)

A123 pouch cells are nice, but there's no suitable DIY connection method thought up yet. Way too time consuming & flimsy in my honest opinion. Thun/Calb/Head. batteries are difficult enough to work with as they come with ready to use connection terminals... prevent projects within projects...


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## frodus (Apr 12, 2008)

steven4601 said:


> A123 pouch cells are nice, but there's no suitable DIY connection method thought up yet. Way too time consuming & flimsy in my honest opinion. Thun/Calb/Head. batteries are difficult enough to work with as they come with ready to use connection terminals... prevent projects within projects...


+1 for that, based on personal experience with TS/SE/CALB/Headway/A123 Cylindrical/A123 Pouch/Lipo Pouch. Screw/bolt terminals are MUCH easier.


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## Brute Force (Aug 28, 2010)

Unofficial, but in stock here in the USA:

http://evtvshop.projectooc.com/products.php?cat=10


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## rwaudio (May 22, 2008)

steven4601 said:


> A123 pouch cells are nice, but there's no suitable DIY connection method thought up yet. Way too time consuming & flimsy in my honest opinion. Thun/Calb/Head. batteries are difficult enough to work with as they come with ready to use connection terminals... prevent projects within projects...





frodus said:


> +1 for that, based on personal experience with TS/SE/CALB/Headway/A123 Cylindrical/A123 Pouch/Lipo Pouch. Screw/bolt terminals are MUCH easier.


Although I love these cells I 100% agree with both of you. If there was an alternative I would be all over it. These A123 cells are a pain in the A$$ to use, the project to be able to use these in my conversion is larger than any other single portion of the conversion itself, if I was using prismatics or even headways I would have been driving last year. I have a small CNC mill at home and I already manufacture aluminium brackets that I sell to other companies. Without already being set up for this I would say these cells just aren't worth it for a car (e-bike maybe as the current requirements are lower). I finally finished my FIRST module (of 24) that will actually go into the car. I've made many, many test modules and stuff that ended up getting taken apart, I went through a few different revisions of the design and for the first time I am happy and confident in the results. The key being Nord-Lock washers and less aluminium spacers between cell tabs along with absolutely OCD/Anal attention to detail on preparing, cleaning, aligning and bolting the tabs together.

If the other available cells meet your design requirements for power output then use them. If A123 pouches are the only cells that will make your conversion do what you want then settle in for a time consuming but worthwhile learning experience in electro-mechanical assembly.

Good luck.


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## crashedup (Oct 28, 2008)

I wrote to http://www.mavizen.com/ for a quote on there A123 prismatic pouch cells. And wow sticker shock is an understatment! There 20Ah cells go for $100 the price goes down the more you buy, but for a 20kw pack you would need around 314 cells give or take , they would come out to 73$ each. For a total of $22,900.00 ,20kw headway pack comes out to around $9000.00
Now thats a big differance. 
But now ive just seen the link for those china made ones wich on the mavizen site say they are defect and potentaly dangerous cells. But $31.00 each instead of $73 . That puts them at around the same price as the headways. Very interesting!!


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## rwaudio (May 22, 2008)

crashedup said:


> I wrote to http://www.mavizen.com/ for a quote on there A123 prismatic pouch cells. And wow sticker shock is an understatment! There 20Ah cells go for $100 the price goes down the more you buy, but for a 20kw pack you would need around 314 cells give or take , they would come out to 73$ each. For a total of $22,900.00 ,20kw headway pack comes out to around $9000.00
> Now thats a big differance.
> But now ive just seen the link for those china made ones wich on the mavizen site say they are defect and potentaly dangerous cells. But $31.00 each instead of $73 . That puts them at around the same price as the headways. Very interesting!!


From Victpower the A123 20Ah cells are under $18 a piece......
Still a pain in the you know what to work with, but awesome power, good price, questionable origin.


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## Yabert (Feb 7, 2010)

crashedup said:


> for a 20kw pack you would need around 314 cells give or take , they would come out to 73$ each. For a total of $22,900.00 ,20kw headway pack comes out to around $9000.00
> Now thats a big differance.


Another important difference is than 20 *Kwh* of A123 AMP20 weight 345 lbs (cells only) and same capacity of Headway will weight 454 lbs (10Ah) or 567 lbs (8Ah).

The A123 will also take less space, but like other guys said, the battery fabrication will be more complex.


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## crashedup (Oct 28, 2008)

I used to work as a technician in a company called bathium where i was in the rnd department , we were developing LMP batteries (lithium metal polymer) for a prototype car called the "blue car". To make a long story short, we used to use a *ultrasonic welder* to weld each cell into packs of 48volts woked pretty good. and used a sheet of polypropylene between each cell for added insulation. when we welded the cells we also added copper pins to the cell tabs for battery managment.However if for some reason you need to dismantle the packs afterwards and recycle the cells it would be difficult because the tabs end up being pretty short after cutting them to take apart.
Anyways this could be an interesting methode for making packs with those A123 cells!


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