a123 32157 8ah pack builds?

[BiGH]

Hi all,
just looking to see if anyone has built an a123 pack from the 32157 based cells that appear around the place ie:

I'm looking at building a pack using these cells (or headway as the alternative) and screw connectors joining the cells.

at the moment i'm thinking these cells would be better than the headway ones. Does anyone have thoughts? suggestions please?

Kind Regards,
Haydon

 

[arkmundi]

I'd try to talk to ES folks who have sourced A123 cells through OSN first. Legitimate sourcing of A123 cells has recently grown here in the ES community. Its a question a reliability and not the underlying cells.

 

[BiGH]

thanks for the tip re osn. I always look around for the right distributor, i'm just interested in screw together packs, and looking at options at the moment.

so far im thinking of:

16s2p AHR32113 pack
16s1p AHR32157 pack
16s1p headway 8 or 10 ah pack.

But there appears to be almost no builds of a123 packs (that aren't spot welded).

edit: i want to build something like this:

 

[davec]

osn sells fake dumpster garbage
the a123 AHR32113 are not common because it's simply overpriced
the 32157 cells dont even show up on the a123 website as an official product- maybe w9 can comment

 

[BiGH]

osn sells fake dumpster garbage
the a123 AHR32113 are not common because it's simply overpriced
the 32157 cells dont even show up on the a123 website as an official product- maybe w9 can comment

yes doing a bit of a pricing comparison i do agree. ~2x the cost of headway for a123s.

The other thing i noticed that comparing headway to the AHR32113 dimensions and weight
hw: 122 x 38 330g 10ah
a123:113 x 32 205g 4.4ah

 

[Hillhater]

You cant really compare the A123 32157 to any Headway cell,...the performance of the A123 is far superior, They are rated for 30C continuous, 60C burst .
Another ES member "major" ran some tests on these cells a while ago.
http://www.diyelectriccar.com/forums/showthread.php/a123-m1-b-tests-83331.html
I think the 32157 is a discontinued product, (unfortunately !) ,
...which is why it doesnt show up in the stock lists.

 

[999zip999]

I'll take a 12ah A123 screw top round cell A123 spec's @ 30C or just 20C is fine. Now price ?

 

[major]

You cant really compare the A123 32157 to any Headway cell,...the performance of the A123 is far superior, They are rated for 30C continuous, 60C burst .
Another ES member "major" ran some tests on these cells a while ago.
http://www.diyelectriccar.com/forums/showthread.php/a123-m1-b-tests-83331.html
I think the 32157 is a discontinued product, (unfortunately !) ,
...which is why it doesnt show up in the stock lists.

Yep, those are impressive cells. Here is a load test I did at nearly 50C.

My current transformer maxed out at 375A (10V for its output), so the initial peak current is a bit higher. Also note that cell voltage drops to just about one half which indicates this is at peak power out of this cell. I think it ran for about 35 seconds. Nice long pulse The little sucker was pretty warm. About 160ºF. And it seemed consistent across the cell body. Terminals were actually cooler, about 100º.

I figure this is about a 47C rate.

 

[BiGH]

That is very impressive indeed... does anyone know where I can purchase these? (reliable seller) with screw terminals?

 

[wb9k]

Screw termimal cylindricals were only made as prototypes to my knowledge. I've seen them in 32113 size as well. The 32157 is a rare size, but A123 has indeed made some quantity of these. I actually have some waiting in the wings here for myself, but I don't believe they have the screw terminals. The cells from OSN are probably genuine, but provenance and quality (they could be "B"-grade, for example) are probably unknown. If the seller guarantees a certain capacity and DCR, you could go for it with reasonable confidence. As always, any purchase from an unauthorized dealer carries some risk.

 

[999zip999]

OSN has there own screw top welder.

 

[wb9k]

OSN has there own screw top welder.

Ah, well.....then there's no way for me to know what's been done here or if it's OK. OSN seems to have a better rep than some grey-market sellers, but the bar is pretty darn low.

 

[999zip999]

I think china has some type of battery wholesale action. That sells lot's of different size batch of cells that this wholesaler resells to battery vendors to make packs or resell.
Now this is only a quess so let's not blow this answer out of the water or light it on fire.
Don't know how's back door is open or when.
I could ask but won't tell.

 

[Hummina Shadeeba]

Bigh did you decide on cells? I'm looking for screw top a123s as well if they're shown to be legit or have similar performance to the real ones. If not I'll go for the headway. Or are there any other screw terminals/destributors that people like?
The screw terminals seem ideal for making a pack. I was hoping to screw them into a mount other than the housing typically used that would allow no expansion and would be the sole means of holding the battery: bolted to the bottom of a skateboard. Do you think an unmovable mount without any room for expansion would damage the cells or risk breaking from expansion? I'm also assuming ricocheting rocks or pebbles won't be a problem. I won't send them into thermal runaway at least

 

[wb9k]

Bigh did you decide on cells? I'm looking for screw top a123s as well if they're shown to be legit or have similar performance to the real ones. If not I'll go for the headway. Or are there any other screw terminals/destributors that people like?
The screw terminals seem ideal for making a pack. I was hoping to screw them into a mount other than the housing typically used that would allow no expansion and would be the sole means of holding the battery: bolted to the bottom of a skateboard. Do you think an unmovable mount without any room for expansion would damage the cells or risk breaking from expansion? I'm also assuming ricocheting rocks or pebbles won't be a problem. I won't send them into thermal runaway at least

It depends on current. For a skateboard, I would think heat is not going to be a big problem, but I really have no idea what your numbers are. Just as importantly, the cells must be physically protected. The can of these cells is at cathode potential. Avoid creating breaches of the PET sleeve or denting the cans and be careful of any metal objects that might get lodged between cells that are in series (rather than parallel) with each other in a pack. I don't think you're likely to make parts that can compress a swelling can, so if anything goes, it will probably be the mounting system. Whatever you use, it must shield the cells from debris. The cans aren't as fragile as the pouch cells, but you don't want rocks bouncing off them for sure. What are the performance goals for your system?

 

[Hummina Shadeeba]

Bigh did you decide on cells? I'm looking for screw top a123s as well if they're shown to be legit or have similar performance to the real ones. If not I'll go for the headway. Or are there any other screw terminals/destributors that people like?
The screw terminals seem ideal for making a pack. I was hoping to screw them into a mount other than the housing typically used that would allow no expansion and would be the sole means of holding the battery: bolted to the bottom of a skateboard. Do you think an unmovable mount without any room for expansion would damage the cells or risk breaking from expansion? I'm also assuming ricocheting rocks or pebbles won't be a problem. I won't send them into thermal runaway at least

It depends on current. For a skateboard, I would think heat is not going to be a big problem, but I really have no idea what your numbers are. Just as importantly, the cells must be physically protected. The can of these cells is at cathode potential. Avoid creating breaches of the PET sleeve or denting the cans and be careful of any metal objects that might get lodged between cells that are in series (rather than parallel) with each other in a pack. I don't think you're likely to make parts that can compress a swelling can, so if anything goes, it will probably be the mounting system. Whatever you use, it must shield the cells from debris. The cans aren't as fragile as the pouch cells, but you don't want rocks bouncing off them for sure. What are the performance goals for your system?

I can't find it now but someone else has made a board with what look like headway red cells exposed on the bottom. looks cool and simple but if you say it's not safe I'll reconsider. Maybe some kind of protective rubber paint would be good enough?
Other than being able to comfortably hit maybe 50 amps continuous the rest seems optional. Was hoping to bolt 8 or 10ah to the bottom and they'd connect to two 30v esc through a bms.
I've asked this question on here already and haven't heard..probably should just write a seller, but, my plan is, and I may have things wrong, ...bolt the exposed cells on the board's bottom somewhat recessed, ad a bms, on/off switch, and a charging port, and then charge solely with a 30v and appropriate current power cord/inverter similar to a laptop charger. And here's the part I don't know: will the bms charge each cell individually till full charge or will the bms shut all the charging once one cell hits the max voltage and leave the rest possibly under? I was imagining if the bms doesn't do all the cells individually I could use a simple $2 voltmeter and go through my 8 cells individually every couple rides or so and find the highest cell and discharge it by hand with a big resistor. I'd be balancing by hand every once in awhile and I think it sounds kinda fun and then Id be more personally involved
Maybe it's because they look like old school d batteries but the chemistry and shape has me feeling safe enough that the cells could be exposed under the board. I heard I'd need roughly 36v to get through the skin, and if I avoided puddles and rain? The lipos freak me out but how hard is it to zap yourself with these.
I'm feeling much safer with a switch. The little battery plugs are creepy

 

[wb9k]

Shock hazard isn't the issue at these voltages. You could get a little tingle here and there, but that's not enough voltage to electrocute you. Any cylindrical cell that gets dented badly enough can burn. Cells in any EV should never be exposed to the environment or the possibility of any physical damage during normal operation. Cells out in the open on the bottom of a skateboard sounds like a formula for a short-lived battery to me.

 

[Hummina Shadeeba]

How bout the expansion? You think if I permenantly mounted the terminals, locked into a rigid position they'd break the mount? The case is metal and honestly doesn't look like it even could expand.

 

[wb9k]

Expansion should not be enough to cause breakage of any mounting under normal conditions. Depending on a number of factors it could conceivably happen over a long period of time. Without pics or hard numbers it's hard to say for sure what may or may not happen, but this is a pretty remote risk I think.

 

[999zip999]

You need a protective box for impact and water. The pack should be made as one solid pack then put in a box.
The bms shuts off charg when one cell hits hvc the bms bleeds high cell the charger turns on till to next cell ( cells ) hit hvc and so on, till balance . If you have the right charger. I like the cells. Hard case protection, screw top, over the top c~rate. Screw those 2c cells running at 2c.

 

[Hummina Shadeeba]

I called headway and yea they said expansion shouldn't be a problem. He didn't think mounting them to the bottom of a skateboard exposed wasn't the safest way to do it but didn't scream foul.
He made a distinction between a bms and pcm. He said the pcm, which is more complicated than a bms, stops the charge when any cells hits 3.8, the cell will then drop down in voltage, and then there's charging again. As far as the details of bleeding or how much ballancing that does I'll have to see but it sounds good enough for everyone.
I'll bolt them to the bottom of the board and...see what happens

 

[quamau]

Just want to let you know that I am using a pack of 16 A123 32113, and I am very satisfied with it.

I am quite sure they are not legit. The weld job sure it's machine made, but it is clearly done afterwards. The weld is extremely weak mechanically, especially at the aluminum side: you either need the spacers or a very flexible connection. I ended up breaking two of them while learning-by-doing :-(

I tested every cell upon receiving them: they were in ok condition but exceeded 4.2Ah (out of the nominal 4.4Ah) only at very low discharge rate. Under load they are more like 3.5Ah. I'd bet third-hand, with at least one passage from China, perhaps osn itself.

And, men, they are bulky and do weigh and do cost! I bought them in the hope of having the least adverse effect from low temperature. So far so good: I am running them at 5C and work extremely well since about two years. These days their controller is out of service so I'm also using a pack of 16 Headway 38140 with 12Ah on the backup bike. Although I have peace of mind as pack is discharging at 2C only, in terms of sag on cold conditions it's an entirely different world...