After many many attemps we have the option...

4464 Views 28 Replies 9 Participants Last post by pm_dawn, Dec 2, 2010

LithiumaniacsEVRacing

Discussion Starter · Nov 27, 2010 (Edited)

now to buy A123 batteries. I cannot get into specifics, but the only issue is we must build our own packs to supply our needs. Lots of soldering, looking for a company that can "handle" this process for us, any suggestions?

Option two is to buy Saft Batteries, but they have not answered our requests "yet". The Saft Batteries would be much easier to build a large pack.

1 - 20 of 29 Posts

LiFe

· #2 · Nov 27, 2010

LithiumaniacsEVRacing said:
now to buy A123 batteries. I cannot get into specifics, but the only issue is we must build our own packs to supply our needs. Lots of soldering, looking for a company that can "handle" this process for us, any suggestions?

Option two is to buy Saft Batteries, but they have not answered our requests "yet". The Saft Batteries would be much easier to build a large pack.

Are serious about soldering a race pack

You need to buy the specific equipment and do it yourself. Spend a little time learning the basics. "Soldering" is for the village idiot. And only a shade tree tosser would lay waste to legitimate A123 made-and-tested cells by soldering them together.

Purchase a Miyachi Inverter welder, or an AC model Mitachi with at least a 3500amp rated transformer to weld the cells to nickel interconnects, or bump the power to 5000amp and do it with copper foil using tungsten electrodes.
When you're done with it, you can sell the setup to the next hillbilly ready to light their pants on fire

Saft? those frogs can't provide you with intelligent advice on how to assemble a safe and reliable pack. There's a lot to learn about stud cells, and they're not intended for mechanically supporting the cell.

LithiumaniacsEVRacing

Discussion Starter · #3 · Nov 27, 2010

Thanks, I didn't intend on building the pack myself. I used the word "soldering" as a basic welding term. I will have a professional build my pack.

LiFe said:
Are serious about soldering a race pack You need to buy the specific equipment and do it yourself. Spend a little time learning the basics. "Soldering" is for the village idiot. And only a shade tree tosser would lay waste to legitimate A123 made-and-tested cells by soldering them together.

Purchase a Miyachi Inverter welder, or an AC model Mitachi with at least a 3500amp rated transformer to weld the cells to nickel interconnects, or bump the power to 5000amp and do it with copper foil using tungsten electrodes.
When you're done with it, you can sell the setup to the next hillbilly ready to light their pants on fire

Saft? those frogs can't provide you with intelligent advice on how to assemble a safe and reliable pack. There's a lot to learn about stud cells, and they're not intended for mechanically supporting the cell.

G

· #4 · Nov 27, 2010

For liability reasons i doubt you will find someone to do that for you. It is a racing application and can't be guaranteed. You need to buy the equipment and tab them yourself. You are the racer and need to know exactly what goes into your vehicle. Not what someone else has done. If someone else does it for you, you then have the option to sue if something goes bad and I am sure with that kind of money involved you would. So get off the wagon and get into the shop and do some work. Learn. Grow. WIN.

toddshotrods

· #5 · Nov 27, 2010

Observation of the currently active racers does seem to confirm what they're saying. They usually have a team member who learns the process and does the welding. This really is the downside of the M1 cells. If you can work your way into a deal with pouch cells you'd be much better off, IMO. I was set and determined to use M1s until I really took a look at the new pouch cells. You can get them with even higher power density than the M1s, and you're talking hundreds of (pouch) cells instead of thousands (of cylindrical). Also, fewer connetions means less chance of something going horribly wrong. It's worth a look, before spending money.

LiFe

· #6 · Nov 27, 2010

toddshotrods said:
Observation of the currently active racers does seem to confirm what they're saying. They usually have a team member who learns the process and does the welding. This really is the downside of the M1 cells. If you can work your way into a deal with pouch cells you'd be much better off, IMO. I was set and determined to use M1s until I really took a look at the new pouch cells. You can get them with even higher power density than the M1s, and you're talking hundreds of (pouch) cells instead of thousands (of cylindrical). Also, fewer connetions means less chance of something going horribly wrong. It's worth a look, before spending money.

A123 pouch cells are basically off the table. In any case, I completely agree with you on your choice.

http://www.diyelectriccar.com/forums/showthread.php?p=210285#post210285

LithiumaniacsEVRacing

Discussion Starter · #7 · Nov 27, 2010

Pouch cells have less ratings if I am correct, I will take another look.

LithiumaniacsEVRacing

Discussion Starter · #8 · Nov 27, 2010

I have the skills, its the time I do not have. But, I have members that will be willing to help. We will get it done no matter what it takes.

gottdi said:
For liability reasons i doubt you will find someone to do that for you. It is a racing application and can't be guaranteed. You need to buy the equipment and tab them yourself. You are the racer and need to know exactly what goes into your vehicle. Not what someone else has done. If someone else does it for you, you then have the option to sue if something goes bad and I am sure with that kind of money involved you would. So get off the wagon and get into the shop and do some work. Learn. Grow. WIN.

toddshotrods

· #9 · Nov 27, 2010 (Edited)

LithiumaniacsEVRacing said:
Pouch cells have less ratings if I am correct, I will take another look.

There are high energy pouch cells and high power pouch cells. The high power cells are what you want for racing and the best of them have a higher power density than even the all-powerful 26650 M1 cells from A123. I think their best high power pouch cells do as well, but they're not for human consumption. Even Croation super powers can't get them. Just being silly Cro.

I looked at Kokams, like WZ is using - they're pretty impressive. The downside, according to the published stats is a really short cycle life, but Wayland says they have tested them for something like a couple thousand cycles, with more left in 'em. I think his comment is in the 10.25 thread here about the WZ. The ones I like say 500 cycle lifespan.

LithiumaniacsEVRacing

Discussion Starter · #10 · Nov 28, 2010

The only pouch cells i have found with the ratings i need are very expensive from Kokam. I do not have the relationship that Wayland has yet.

Is there a "cheaper" brand of pouch cells that will give me the ratings I need?

toddshotrods said:
Observation of the currently active racers does seem to confirm what they're saying. They usually have a team member who learns the process and does the welding. This really is the downside of the M1 cells. If you can work your way into a deal with pouch cells you'd be much better off, IMO. I was set and determined to use M1s until I really took a look at the new pouch cells. You can get them with even higher power density than the M1s, and you're talking hundreds of (pouch) cells instead of thousands (of cylindrical). Also, fewer connetions means less chance of something going horribly wrong. It's worth a look, before spending money.

LithiumaniacsEVRacing

Discussion Starter · #11 · Nov 28, 2010

Please let me know all you can find out on pouch cells. have you seen this website:

http://www.proev.com/P1Batt.htm

Each cell is $666.00 bucks?

toddshotrods said:
Observation of the currently active racers does seem to confirm what they're saying. They usually have a team member who learns the process and does the welding. This really is the downside of the M1 cells. If you can work your way into a deal with pouch cells you'd be much better off, IMO. I was set and determined to use M1s until I really took a look at the new pouch cells. You can get them with even higher power density than the M1s, and you're talking hundreds of (pouch) cells instead of thousands (of cylindrical). Also, fewer connetions means less chance of something going horribly wrong. It's worth a look, before spending money.

JRP3

· #12 · Nov 30, 2010

LithiumaniacsEVRacing said:
The only pouch cells i have found with the ratings i need are very expensive from Kokam. I do not have the relationship that Wayland has yet.

Is there a "cheaper" brand of pouch cells that will give me the ratings I need?

I thought you were willing to pay to play

toddshotrods

· #13 · Nov 30, 2010

LithiumaniacsEVRacing said:
Please let me know all you can find out on pouch cells. have you seen this website:

http://www.proev.com/P1Batt.htm

Each cell is $666.00 bucks?

Yes, Kokams are very expensive. My desired Kokam pack is nearly twice the price of the A123 pack I wanted (though lighter and more powerful).

JRP3 said:
I thought you were willing to pay to play

That's what I keep saying. You're sending mixed signals.

LithiumaniacsEVRacing said:
Please let me know all you can find out on pouch cells...

You're kind of on your own there dude, outside of the basic info we've been sharing. I am not ready to build my pack yet, and basic research is as far as I plan to go until I have a working vehicle to sort the rest of the details out, and to show any battery manufacturer I'm dealing with "what I'm working with".

I did my research to find out what kind of pack I needed, and what would work best for my goals. It's a long road from where I am to the ultimate performance goals I have, so that all goes on hold for a while. I'll probably throw together a "cheap" Headway pack to do some initial testing, sort through some of the bugs, and make final decisions. I still think you're going about this all wrong. Even pro racers, with multi-million-dollar budgets have tons of issues to sort through to get a car up and running. Just swiping plastic, and throwing a bunch of parts together, isn't the path to record-setting performance. You need to accumulate a lot of hard data. I shouldn't have to tell you that racing is an incremental process. You build upon a foundation, towards a set of goals, analyzing and adjusting as you go. The most important part of that whole process is the foundation.

Put some motors and batteries in that thing and start pounding on it, before you spend $30-50K on a battery pack. Wayland, Dube, and Lawless, all had a significant amount of track time - in their EVs - before they set records in them. I'm an old-school ICE drag racer as well (I've lived and breathed this stuff since I was 14-16) and a lot of that experience doesn't translate directly to EVs. It helps, but is not a direct transfer of knowledge, because of the nature of the beast (the electric motor).

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ewert

· #14 · Nov 30, 2010

If money is not much of an issue, you could just throw together enough of those 90C burst RC batteries (Turnigy nano-tech from Hobbyking) for whatever max volt max amp draw you can get from the controller / motor you put in your car. So they might have crap-o-la cyclelife. They have insane kW/weight and kW/$ ratios. Was it $5000 for around 1MW burst power (for 40 secs

).

Firehazards? No problem for drag teams, yes? Short cycle life? Well it is a test battery for controller/motor. Have to do manual construction? Prolly less than on zillion A123? ... What's not to like, as they are buyable right now. So you might burn them out "fast", but they are cheap/kW ...

toddshotrods

· #15 · Nov 30, 2010

ewert said:
If money is not much of an issue, you could just throw together enough of those 90C burst RC batteries (Turnigy nano-tech from Hobbyking) for whatever max volt max amp draw you can get from the controller / motor you put in your car. So they might have crap-o-la cyclelife. They have insane kW/weight and kW/$ ratios. Was it $5000 for around 1MW burst power (for 40 secs ).

Firehazards? No problem for drag teams, yes? Short cycle life? Well it is a test battery for controller/motor. Have to do manual construction? Prolly less than on zillion A123? ... What's not to like, as they are buyable right now. So you might burn them out "fast", but they are cheap/kW ...

I've thought about those. Links and info were posted here before. I am curious about the connections. I think I remember seeing something like 4mm wires. Seems like a lot of current through such a small connection. There was a guy on NEDRA who claimed to be building a 300+v/2Kamp pack that would weigh less than 200lbs. I think it was supposed to have a 90c rate, and he admitted it was just a drag race setup (not much range) - sound like these RC cells.

I might consider it, but again you become part racer/part battery tester with something like this. If the primary goal is experimenting with advanced EV componentry, and seeing what it will do, this is a great idea. If one's primary goal is record setting performance, you're adding a whole new dimension to the plan that could be a hindrance to acheiving the main goals. In that case it would be wiser to use a proven technology and adopt new ideas after they have been proven.

DavidDymaxion

· #16 · Nov 30, 2010

BYU used the stock A123 connections -- but they were running about 50 A per cell, not the much higher Amps the Killacycle team runs. You can see some pics here:

http://explodingdinosaurs.com/byugarage

They run the 10 cells in series from a DeWalt tool battery pack using the stock connections, and then ran wires across each group of cells to put them in parallel.

pm_dawn

· #17 · Nov 30, 2010

You can check these out.

http://www.eigbattery.com/

Check the Product Tab and Cells
They have both Lipo pouches and LiFePo4 Pouches. Up to 30C in the LiFePo4.

I think they are willing to sell in small quantities.

Regards
/Per

JRP3

· #18 · Nov 30, 2010

ewert said:
If money is not much of an issue, you could just throw together enough of those 90C burst RC batteries (Turnigy nano-tech from Hobbyking)

I've heard they don't really do anywhere near 90C.

pm_dawn

· #19 · Nov 30, 2010

Not what I heard.

http://endless-sphere.com/forums/viewtopic.php?f=14&t=22464

regards
/Per

DavidDymaxion

· #20 · Nov 30, 2010 (Edited)

Something I forgot: Bill Dube has a bead on someone that'll build you an A123 pack (it might be him or someone he knows, not sure which). You can contact him on the NEDRA board.

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