A123 20AHr Pouch Cell Battery Build & Info Thread

[agniusm]

Hi. I would reconsider using brass. Have you calculated resistance on brass? I did and it is less than aluminum. Second is weight, trust me it adds a ton to the pack, bad for EV use. If you going to use brass flat bar to connect cells in 3,4,5P configuration which i bet is meant for cars and bikes you will have problems regarding conductivity. I tested mine with 211amps and my blocks which are just clamping tabs get worm. Solitons and zillas go beyond 1k amps Just my point of view.

The brass won't be taking any of the current - the 1.6 mm copper plate goes on top to clamp the tabs down - this is what will be taking the current. The brass is simply there to provide good tension when tightening the copper down. Brass is a pain to work with, but that's why I'll get a fabrication shop to do it for me. The other benefit of brass is that it can be soldered down onto the pads on the PCB to hold it in place. Then, traces can be run from the pads to serial sockets.

As for weight, yes, I know it gets heavy, but the brass component of my car battery will really only be adding 3 kg to the whole 25 kWh pack. The copper will be an additional 7 kg, so 10 kg all up. I don't think it will matter much on a 950 kg car.

Ok, missed that part, was looking at the image . Copper will be best for this and 10kg is nothing for sure.

[999zip999]

I order from McMaster for the Drutledge build tuesday 2pm and got it 4pm wed. Wow. Charging 6s with 4 voltfreacks 3.65v2a. Have a hyperion but love those little things for A123 and headways voltage. See how long this takes.

[999zip999]

I found 1/4 od x.170 poly tube I think for ice cube maker. Perfect even fit's thru the punch hole in the tabs ( paper punch ) one peice.

[ohzee]

Yea I used the same stuff for my build worked pretty good for me.

[999zip999]

My fluke 113 won't pickup the 3.32v, But my free ( coupon ) H.F. m.m. does ? ? Can't wait for those voltfreaks and hooked up the 1420 for 11a on 6s to 3.62v. An old 10in. carbide 40t on a chop saw cuts the 1/4in. alumiun bar just fine.

[999zip999]

Drill the holes in the tabs a little bigger as to free them up. Do I use the grease ? What grease ? local hardware stuff or home depot or forget it ?

[docnjoj]

I'm waiting for my agniusm kits to arrive but in the meantime I;'ve used my No-Ox ID-A on all my plugs and outlets outdoors and by the pool. It seems to really help conductivity since when I do a before and after with a Killowatt meter the current draw seems to be about 1 amp in 10 lower. Maybe a fluke but I will swear by this stuff and use it on my 12S battery when the kit comes. Seems like good stuff.
otherDoc

[ambroseliao]

I bought some Noalox in preparation for my A123 build. Has anyone else used this stuff?

http://www.idealindustries.com/prodDeta ... dId=noalox

Ambrose

[999zip999]

Yes Ambro i think that's the stuff from home depot. Is there some high temp. or something ?

[999zip999]

O.k. the drills don't work for the tabs even the drill point, but from dewalt little different center drill. I use a 3m paper pouch wit the two outer punches taken out, perfect. The bule plastic the drill drifted even in a dril vise with 3/32 pilot hole ? No problem. The 3/32 drill for the 4/40 is small so ream the hole with the drill or find the right drill. Put a wooden cloths clip on 6s parelle at 3.6v for balance.

[josh786]

Here is what I have been working on. I have to give thanks to all the people that contribute to this forum I got all my ideas from others builds. (Long time lurker) The green stuff is urethane with copper inserts. I plan on putting a tube thru the holes before I put the bolts in. There will be a wire that will exit into the middle from the series bus bar for BMS. With this I think I will have every possible configuration covered. Feed back is welcome will start making molds next week. Still having a hard time with copper vs aluminum for the bus bars.

[bigmoose]

Josh your design was so elegant, I thought the pixs should show in line.

4S2P complete 2b.jpg (28.42 KiB) Viewed 1006 times

4S2P completeb.jpg (34.04 KiB) Viewed 1006 times

[docnjoj]

Hey Josh! That is an interessting and clever design. Will the urethane be cast, like the kind for making model railroad parts?
otherDoc

[josh786]

The parts will be made from urethane adhesive (I build the equipment at work) we have alot of left over product. Once the molds are made the cost will be just the copper + time. I am not sure about the compression strength of the modeling urethane, the stuff we have will set hard enough to thread.

[docnjoj]

Thanks Josh it sounds quite solid!
otherDoc

[bigmoose]

Josh, just a thought to not forget the balance wires. That may be what the hole for is on top of the conductor in your green molded piece. If not, we should figure out how to elegantly attach a balance wire.

[josh786]

Big, My though was to solder a wire to the S plates that will exit into the V on the top. I have some 6061-T6 aluminum (1/2 X 2 should be good to 700-1000amps?) that I can use to build the prototype but the wire attachment is what is holding me up. Might just drill and tap a hole and use a plated ring terminal but I am not sure about longevity there will no way to fix it later. I have no problem with using copper for the final product just that I have the aluminum and I am getting antsy. I am trying to extend the end plates down to contain the cells but it is getting very bulky. May need to rethink how the cell terminal sits so the end plate can be thinner. Ideas?

Josh

[999zip999]

If it's 2p can you get rid of the buss between the parelle's with it being tab to tab ? Will this srcew of the spacing ? Yes alumiun is hard to think of over copper. As in houses ect. and how hot it can get ? I guess it's all about mass. To a point of to to much heat.

[josh786]

Here is what I have currently. If the pic shows up inline.

4S2P complete 3.JPG

(82.28 KiB) Downloaded 3 times

Mod Edit: I resized your pix. It has to be below 800 pixels in width to show up in line. (one of the boards little quirks!)

4S2P complete 3-600px.JPG (82.28 KiB) Viewed 1007 times

I added the holes for the balance wires. The lines in the top of the plates are to mark the connections. This would have plastic or steel shipping bands wrapped around to hold the cells. Maybe getting to heavy for a bike?

[josh786]

Zip, Removing the bus from the 2P makes the S plates wider, may have to think about it more. My plan was to be able to reconfigure this to any size pack by changing out the plates. What about terminals stud vs. taped hole I can see advantages to both.
Josh

[999zip999]

I mean in a 2p pack the cells at 2p will fit togethere in one taps pressed togethere and fit in your buss bar? Only maybe. I find they fit togethere very easily as 2p. But I would like to have one in hand as to help as would you.

[megacycle]

I'm waiting for my agniusm kits to arrive but in the meantime I;'ve used my No-Ox ID-A on all my plugs and outlets outdoors and by the pool. It seems to really help conductivity since when I do a before and after with a Killowatt meter the current draw seems to be about 1 amp in 10 lower. Maybe a fluke but I will swear by this stuff and use it on my 12S battery when the kit comes. Seems like good stuff.
otherDoc

Been through this on agenius kit thread, viewtopic.php?f=14&t=38545&start=135
They ac outlets around the house
Can anybody please proof this stuff decreases resistance to dc
Other than provide corrosion protection is it that much better than vaseline.

[999zip999]

O.k. Vaseline it is. Stiil charging for days. They just look so sleepy.

[megacycle]

Aka snake oil

[999zip999]

When I took apart my ping I put a set of extra balance wires and if i put a bms on these packs I still will have a set of balance wires for checking and balance as probing the bms will mess up the wires and.