Group Buy? Dr.Bass Steveo found 7s3p Module! Awesome Price!!

[deVries]

Yes, you'll get to keep it, and you won't get a refund. The seller has already stated as much.

For the sake of accuracy, no one was ever promised a refund. The seller has stated a replacement warranty for 7s3p, which is the topic of this thread. There never was mentioned a warranty for 28s3p, which someone posted that they won't sell those with a warranty. Fine. We don't need to talk ourselves out of a warranty for 7s3p, now, do we? If you continue on, then this may happen. That's not a good idea, ehh?

We don't need to debate this back and forth "here" on thread, as this is not being productive and helpful from a buyer standpoint. If you need to express more please do so by PM. IMO.

I'm equally sure that the seller in China is not going to count on that honesty and start sending free replacement packs on the basis of a picture of a voltmeter.

Hobby King has routinely allowed for digital photos to be taken for warranty & return issues, so you are just offering an opinion that is giving the seller an "out". Who's side are you on? Anyway, you are not the seller, so it's not for you to push the issue or agenda on their behalf. IMO.

Let's move-on. Debate by PM.

As for obvious poor packaging practices, we need to point that out so hopefully they will correct it! Or, maybe you will be next person with the defective module, because it wasn't packed correctly. The trading company is selling these overseas, because they probably make 10x to 20x times the profit they could selling to a local. They need to package better, period. Again, let's move on.

No need to banter this back and forth on this thread. PM if you must. Thanks! for understanding.

[SlyCayer]

Who's side are you on? Anyway, you are not the seller, so it's not for you to push the issue or agenda on their behalf. IMO.

\o/ I was wondering the same thing, and I agree...

[zEEz]

Sorry if I bother you all
I saw lot of pictures, very cool from the side of who got the toys
.. I mean, to be so fast and precise ... but as a potential buyer, I must say
I'm not so inclined anymore ... oatnet 7s3p modules were kind of in working order ...
... one 28s3p miracle was fine, other 3 were quite abused ...
BUT CLEARLY WE ARE TALKING OF SOME USED CELLS ... and if some module that is 70%
faulty has menaged to show up ... well ... statistics is, what you can tell

Good luck to whom has bought, have fun!

[Ratking]

Also, if you bring up the issue of their packing, you need to tread lightly. This vendor has already threatened to not sell to us over seas customers. If packing them becomes too problematic, they may just say no more sales. Trust me when I say they really don't need our business. There is more than enough of a market in china for these things. They really don't "need" to sell them out of country.

I would like to know more about your inside information. How do you know shit about how the Chinese marked is?
I would say close to the opposite, but thats just my subjective opinion just as yours as long as you don't give us some proof.
It's like you want to feed the seller with arguments.

[999zip999]

Dr.Bass and Steveo how do you name on the top of this thread ?

[zzoing]

victpower is a serious sounding company but the battery i bought from them in 2k9 was technically abit low quality, the cells were not so durable and it went tits up on me when i charged it in 3 4 degrees temperature on a 2.5 amp charger so i think they need some serious considering to review their products first. i had posted to ask about the low temp charging and no one answered at the time, and the victpower leaflet didnt say either... but they were known to be dodgy cells when i posted the image on here afterwards.

ez

[njloof]

If anyone's interested, I just received my 7s3p pack; it seems normal and tests OK on the voltmeter but I think overall it's more of a R&D effort than I'm up for to build a full size car pack. If you're in the US and want to buy it from me I'm happy to send pics; I promise to ship in a much bigger box filled with lots of packing material

[deVries]

Dr.Bass and Steveo how do you name on the top of this thread ?

If you read this thread from the beginning, then the answer is already there. The topic itself answers your question too.

victpower is a serious sounding company but the battery i bought from them in 2k9 was technically abit low quality, the cells were not so durable and it went tits up on me when i charged it in 3 4 degrees temperature on a 2.5 amp charger so i think they need some serious considering to review their products first. i had posted to ask about the low temp charging and no one answered at the time, and the victpower leaflet didnt say either... but they were known to be dodgy cells when i posted the image on here afterwards.

This company trades in all kinds of batteries. In this thread topic we are only discussing the recent A123 modules that have become available with primary focus on 7s3p modules. If you ordered a bigger module, then some limited feedback "here" about the shipping & quality of the module is acceptable too. People can search the ES archives for posts about other batteries from this company, but we need to stay focused only on the A123 modules in this thread, especially, the 7s3p module. Thanks.

If anyone's interested, I just received my 7s3p pack; it seems normal and tests OK on the voltmeter but I think overall it's more of a R&D effort than I'm up for to build a full size car pack. If you're in the US and want to buy it from me I'm happy to send pics; I promise to ship in a much bigger box filled with lots of packing material

Could you please weigh your module & post that info here? (Please use an accurate scale.)

[zaxxon]

If ordering the 28s3p, then I definitely suggest *insisting* that much more foam protection is used. These modules are expensive & there is no reason -or- "excuse" they should not package these much more carefully with foam padding all sides AND also covering the total entire module surface area too, imo.

Zaxxon, where were your three 28s3p modules shipped to?

The module were delivered to US Indiana. From pickup in China to my driveway in 3 days , amazingly fast. There were no added costs or hassle, the payment transaction and delivery arrangements went exceptional well.

The main issue with the shipping packaging IMO is need for additional wood feet in middle and possibly thicker bottom board. The bottom bowed in the middle up to 2.5 cm pulling out nails and unfortunately the module took on that shape. You can imagine the tops of the cells in the middle are under some high stress. I sent picture to Xin and asked her to alert her shipping department. She was very apologetic about it and said she had reviewed issue with them.

[TheWizard]

I ordered 3 7s3p's and just got them today. took about 5 days from Shenzen to Phoenix. the delivery man missed me at my house, so I went to the airport depot and picked em up myself.

The box was 4 pieces of warped 5-ply and tack nails. had i not picked up the pack, it would have probably fallen apart on the next delivery attempt...

one of the packs had an entire series (3 cells) that measured @ 0.8v, but all other cells were topped up to 3.2v. The welds varied in appearance from cell to cell, and a few cells got pushed enough to lift the bus bar out of its plastic clips. nothing I can't fix, and the form factor is perfect for long-distance cargo bike duty (i'll be using 1 pack per bike, maybe double/triple for a big road trip!). the aluminum sides felt cold to the touch after riding around in my truck bed in this summer heat, so i think this container will be good for air-cooling. The pack looks slightly worn from handling but not dirty. a few little dings in the aluminum sides, but nothing catastrophic.

A123 is also a big player in grid storage, I wonder if these packs may be swap-er-oos for a power company customer. I don't understand the economics of A123 shipping these (supposedly) made-in-USA batteries to China (and now back to the US?!), maybe they're trying to maneuver their way around any DOE scrutiny over ARRA's contribution to the development and manufacture of these "defective" packs? at least the merchandise is good, so I'm glad I bit, albeit I don't why the profit had to go to china instead of to A123 who really needs it. Hopefully these will last however long it takes until lithium flow batteries hit the market.

I disconnected the BMS-slave boards to prevent the chance of phantom discharge. I'm not skilled enough to reverse engineer them to be used with my own BMS or charger (which I have yet to buy/make), but I'd be happy to bring one to anybody local that would like to play with it.

pictures are here

[bigmoose]

A123 is also a big player in grid storage, I wonder if these packs may be swap-er-oos for a power company customer.

I wonder if you have something there! The date on the BMS PCB's in your picture is 2009, that would seem to be way too early for use in car production today. I sure wish we knew how to read the production date codes on the cells!

I wouldn't think the utility batteries would be spent in 3 or 4 years, but these could be "culls." Seems to be a weak, or bad, cell group in a statistically significant number of assemblies.

[Pure]

Also, if you bring up the issue of their packing, you need to tread lightly. This vendor has already threatened to not sell to us over seas customers. If packing them becomes too problematic, they may just say no more sales. Trust me when I say they really don't need our business. There is more than enough of a market in china for these things. They really don't "need" to sell them out of country.

I would like to know more about your inside information. How do you know shit about how the Chinese marked is?
I would say close to the opposite, but thats just my subjective opinion just as yours as long as you don't give us some proof.
It's like you want to feed the seller with arguments.

Dude, lighten up.

My inside information? This shit aint no secrete. But I guess none of them want cells with the specs like A123. lol

In China, electric bicycles are leaving cars in the dust. Last year, Chinese bought 21 million e-bikes, compared with 9.4 million autos. While China now has about 25 million cars on the road, it has four times as many e-bikes.

Read more: http://www.time.com/time/world/article/ ... z1trJRXzfA

And never did I suggest that none on ask for better packing. My post was short because I'm busy. Just that when you ask for better packing ask polity and don't be an ass. I've been reading post on here where members are giving this guy crap. I can only imagine how many emails he's getting and of those how many are getting their panties in a wad.

We are dealing with a company in a different country, we need to act accordingly.

[deVries]

I ordered 3 7s3p's and just got them today. took about 5 days from Shenzen to Phoenix. the delivery man missed me at my house, so I went to the airport depot and picked em up myself.

Thank you for your very detailed report. Obviously, packaging needs to improve.

One module per crate would prevent that "bowing issue". IMO.

Can you weigh your modules to give us the individual weight(s) & any variances or differences too, please.

Thanks!

[SlyCayer]

Can you weigh your modules to give us the individual weight(s) & any variances or differences too, please.

Is it me or it's hard to get the weight of the modules? I promise that if we do not have a weight by the time I get mine, I will provide a very accurate weight .

[oatnet]

I took my packs apart today.

Is it me, or do the BMS's STINK? I mean SMELL, really, really bad? The 28s3p had a (2) BMS, one on each end (dated 2010), and all three 7s3p had a single BMS (dated 2009). All but one of the 2009 BMS looked thicker and lighter, tacky to the touch, and I had to take them outside because they were stinking up the garage. I wanted to disconnect them anyhow because I didn't know if they were draining current.

The good news is that all of the cells on my 19v pack are the same voltage - bad that they are all low, but good that none are dead. Every cell of every pack has every voltage! All the the cells were in balance relative to their respective pack. Wonder if it helped that I was a good customer.

I like that the same screws are used to mount the covers and secure the BMS on both types of modules.
I believe that the painted metal seperators are a soft metal cooling fin, so having one side of each cell is enough. The endcaps have nice, big, metal-lined holes through them, providing an excellent mounting points. The 7s have horizontal holes, and the 28s has vertical holes, but I think you can remove the liner and use either set of holes.

Because of the different metal in each tab, the welds on the negative terminals are gold, and the welds on the positive terminals are silver.

1 IMG_1944.JPG (162.46 KiB) Viewed 743 times

Note the dowels demonstrating the vertical mounting holes on the 28s. Now that I have seen professionally installed balance wires, I feel better about my own work. I do appreciate the design feature of the wiring channel up the center.

2 IMG_1943.JPG (89.07 KiB) Viewed 743 times

Note the dowels demonstrating the horizontal mounting holes on the 7s.

3 IMG_1954.JPG (112.62 KiB) Viewed 743 times

Closeup of a horizontal hole

4 IMG_1937.JPG (52.8 KiB) Viewed 743 times

Side view of a row of welds. You can see the different colors of the cell tabs. A very narrow gap between the buss bars, on the left.

4 IMG_1935.JPG (30.64 KiB) Viewed 743 times

A row of welds. A plastic cap sits on top of each cell pair, the tabs stick through, and the buss bar is welded at the top. The screws that secure the top cover of this pack go into knobs in the foreground, which are part of the plastic carrier. I think the tabs are tensioned between the plastic carrier and the buss bar, and I remember Luke saying the tabs couldn't move around or they'd stress-fail, so I figure that is part of their purpose.

5 IMG_1936.JPG (61.09 KiB) Viewed 743 times

Closeup of a tab, and the weld in the upper left corner.

6 IMG_1936_crop1.JPG (56.13 KiB) Viewed 743 times

closeup on a row of welds, note the silver vs copper color.

7 IMG_1936_crop2.JPG (40.69 KiB) Viewed 743 times

On the left, the 2009 BMS that is normal, on the right one of the 2009 BMS's that STINK, are gooey, you can see the color and sorta matte finish on these.

8 IMG_1953.JPG (71.69 KiB) Viewed 743 times

7s (2009) vs 28s (2010) BMS, side 1 (click for large picture)

7s (2009) vs 28s (2010) BMS, side 2 (click for large picture)

Top of a 7s3p (click for large picture)

[deVries]

I took my packs apart today.

Oatnet, JD, thanks for the super pics. Man, those are excellent. Excellent commentary too.

If you get a chance no one has posted yet the weights of individual 7s3p modules. Would appreciate it if you can weigh yours & let us know.

Thanks!

[oatnet]

Can you weigh your modules to give us the individual weight(s) & any variances or differences too, please.

Is it me or it's hard to get the weight of the modules? I promise that if we do not have a weight by the time I get mine, I will provide a very accurate weight .

Just for you, deVries and SlyCayer. 30.6 lbs minus 14 screws, and when I removed the BMS/front cover it dropped to 30lbs even, so maybe 8lbs of packaging/wiring/buss bars on top of the weight of the cells. The others weigh pretty much the same, doesn't matter to me enough to carry them upstairs. The 28s (I am tired of adding "3p" to "7s" and "28s" ) is heavier than I want to lift at the moment.

I forgot to mention - I also like that '+' and '-' shaped holes are stamped through the buss bars that wrap around the terminals on the ends. Also, odd that on the postive terminal both pairs of bolt holes are live, and on the negative side only one pair is, the other is just a mount (see the third picture in my last post). Oh, the bolt holes for the power terminals are standard M6, I just screwed in one of the old bolts from my Headway cells. Judging by the screws that came on (1) 7s, a123 used red locktite on the bolts that secured the terminals, I usually use blue.

I am really pleased to be hands-on with a factory pack, so I know how to better package packs I build from 1s cells.

[deVries]

30.6 lbs minus 14 screws, and when I removed the BMS/front cover it dropped to 30lbs even, so maybe 8lbs of packaging/wiring/buss bars on top of the weight of the cells. The 28s (I am tired of adding "3p" to "7s" and "28s" ) is heavier than I want to lift at the moment.

You can skip the 28s as far as I'm concerned.

I'll be interested in your ideas about repairing that bad "3p cell", when you have time to do that repair. I think you got one low/bad or shorted 3p in a 7s, right...

...2 modules were at 22.x v and the third at 19.x v, so I assume it has a bad 3p cell.

Again, thank you JD for documenting everything you did today! Great stuff to know.

[oatnet]

It turned out that all the cells were at 2.75v in my 'low' 19v pack, but they all had voltage. Hopefully a charge up will fix things.

[SlyCayer]

Just for you, deVries and SlyCayer. 30.6 lbs

Thank you \o/

[davec]

.

[JRP3]

With three cells wired in parallel how are you going to load test a single cell without cutting it out?

[Harold in CR]

So, a 7S3P Module = 21 cells at 67V, correct ?? I have been trying to count cells, but, I get crosseyed.

Thanks for posting those excellent photos, Oatnet.

[Ypedal]

7S = 7 x 3.6 = 25.2v. .. call it roughly 24v

3P = 20ah x 3 = 60 ah

[EVPowers]

7S = 7 x 3.6 = 25.2v. .. call it roughly 24v

I thought these cells had a resting voltage of about 3.3v?