A123 20AHr Pouch Cell Battery Build & Info Thread

[dnmun]

lifepo4 is fully charged at 3.65V and considered fully discharged at 2.1V.

[999zip999]

These are victpower cells from the mid west group buy and just want to bring life to them NO ah test as I can feel in my seat they need a few cycle's to get them filled up. Plus they are in tupperware tubs looking for some armor. Waiting for my updated Lyen 12 fet to run my 2810. So no hurry.

[999zip999]

I made the box for the triangle 12s and 12s in tupperware on the rack. Maybe hang on the front ? The third charge as 24s is great 34mph with a bmc 600hs 30amp. 2150 watts. All well balance after ride 8ah. The 1420 balance prefect to 3.59v. Maybe will be better after a few cycles. Maybe go with the 2810 and a 12fet lyen ? Happy.

[999zip999]

24s as two 12s A123 Off charger 84v. Put it on the bike it drop to 80v. and stay's at 78v on the ride for 17,966mah close to 18ah. cells off charger 3.59v after ride 3.2v and it's all done 76v. almost 18ah. bmc 600hs at 27amps. It likes to live at 78-76v. ? That's where the cells live. No bms.

[ohzee]

Some battery porn figured id take a pic of what I have in my office now.

My latest 24s build with agniusm's kit and an evaasseuble 100/150 Amp BMS A123 20ah pouch cells
20s build using compression and a ping high power BMS A123 20ah pouch cells
small one on the left 12s headway 10ah with a cellman low power BMS

[potatorage]

So I've assembled my pack but I just realized I'm retarded, since I folded the positive tab over the negative one, making soldering on balance leads extremely difficult. What are some other ways of attaching balance leads?

[ohzee]

Can you screw a small screw into it ? Post a pic and it would be easier to come up with a better solution.

At least you got it all together ok.

[docnjoj]

When I messed up the traces on my first 6S build I had to screw the wires at the blocks with one of the button screws. I works fine and Cellog shows all 6 cells are fine.For the second 6S pack I clear nailpolished the traces and at 4 cells finished no problems at the euroconnector.
otherDoc

[oatnet]

So I've assembled my pack but I just realized I'm retarded, since I folded the positive tab over the negative one, making soldering on balance leads extremely difficult. What are some other ways of attaching balance leads?

You would be challanged to solder the balance wires to the tabs even if they were not folded, which is why we are folding instead of soldering tabs. If you look at my guides for folded tabs (linked earlier in this topic), you will see I put the balance wire in with the first fold. You could probably pull back the last fold, insert the balance wire, and fold it down again. Unless you are doing some extreme charging/balancing, that will be plenty of contact to carry the current.

[megacycle]

So I've assembled my pack but I just realized I'm retarded, since I folded the positive tab over the negative one, making soldering on balance leads extremely difficult. What are some other ways of attaching balance leads?

Have you got a photo of that issue?

[potatorage]

The positive tab is always folded over the negative tab. I purchased some solder that contains flux advertised for soldering to aluminum, but the joints are extremely difficult to make and it takes forever. Not to mention they aren't very solid either.

[ohzee]

heck id get a small heavy duty whole punch and just attach some small bolt/nuts.

I think trying to solder is out of the question.

[megacycle]

To get around soldering if your having problems, a lot of us are , could put lead between tabs and clamp around tab with a u shape of say copper, and I'm not sure were you live but some countries use earthing clamps to bond items to earth they are a small C clamp with screws for clamping to thin guage items and usually have a ring lug for connection could make them if your your handy, bent copper and set screws.
Another way is a termi-foil crimp (the weapon of choice ) if you can get some, squeeze on tabs, secretions bite in.
Good luck.

[teklektik]

Another way is a termi-foil crimp (the weapon of choice ) ...

Termi-Foil crimp! Who knew?

termiFoilCrimp.jpg (6.35 KiB) Viewed 744 times

[docnjoj]

Another way is a termi-foil crimp (the weapon of choice ) ...

Termi-Foil crimp! Who knew?

termiFoilCrimp.jpg

They were in a thread (this one?) a while back when Peter Perkins posted about them. They ain't cheep and dont exaactly fit the tabs. Also the crimp tool is about 1000 USD. I believe there was some discussion about trying to make a proper crimp tool from locking pliers. Luckily agniusm came through before anyone got too serious about them, but the idea seems sound.
otherDoc

[teklektik]

They were in a thread (this one?) a while back when Peter Perkins posted about them.

Oops - caught as a casual tail-of-the-thread reader!
You are quite right - here's the post - Thanks!

[agniusm]

Why cant it be drilled 3mm and balance wire bolted through?

[megacycle]

If you did end up sourcing termi-foil, which are like $0.50 each or a sample, could be less than a bolt price and are made for foil connections, similar to this and can be pressed on in a vice, besides Agniusm is right about a bolt, termi-foil punctures the tab too, same as a bolt hole would, just won't look as sexy IMO.

[EVPowers]

I've been down the termifoil path guys, and they require a minimum 2,000 piece order.
Price to the consumer would be about $1.25-$1.50 per connector.
Also there is a 12-14 week lead time.

I'd do it, but I'm not sure I'd ever be able to recoup the money.
Anyone wanna' go in on it with me? (Half serious here.)

I have some at my shop and it can be a bit tricky to correctly crimp.
Their "official" crimping is $600+.

You can make a poor man's termifoil connector with some copper and a hammer and nail.
I have pics somewhere around here.

[megacycle]

http://www.futureelectronics.com/en/Tec ... ICS5513395

Go half, 1/3rds, sorry 1/5ths dont need that many yet, got $50 spare.

Because we're on balance leads it only has to take say 10 amps max.
So maybe could use copper foil and a meat tenderizer half

[EVPowers]

Butt splices you linked to are not the same as the one in teklektik's post.
Cost is much different.
I notice that even on the butt splices there is a 500 piece minimum order and they do not stock them.

[drutledge]

I realized I never finished my build posts and thought I'd add some shots of my finished project.

I used ''Garolite' (think thin fiberglas) along with some strips of spring steel in between to add rigidity when then plates are clamped together. I threaded each bolt through some thin tubing to reduce conductivity between the pouches and the bolts. I placed some very thin,somewhat rigid foam between the two end pouches and the plates to better keep everything in place.

I've used this pack for about 500 miles and 30 recharge cycles. So far so good.

IMG_2772 3.58.43 PM.JPG

(247.83 KiB) Downloaded 4 times

[ambroseliao]

Beautiful! Do you have any shots of your pack on your vehicle?

[megacycle]

Butt splices you linked to are not the same as the one in teklektik's post.
Cost is much different.
I notice that even on the butt splices there is a 500 piece minimum order and they do not stock them.

These are a different splice to those being considered on the Honda forum, as my set up was different and i did a fair amount of research on using them for a pack, in saying that the application considered in this thread is for balancing which is usually < 10A.
Its a shame they are not in stock,
I might bite the bullet in the near future and buy 500.

[999zip999]

I made one out of copper I forgot to heat it up and drop it in water befor folding. As you fold on it will harden and maybe crack.