Dr.Bass Steveo found 7s3p Module! Awesome Price!!

The 7s3p or 42s3p packs sounds great for an EV car, if the case is professional than I can save some time and money by buying these complete packs.
But are the tabs inside the good enough for 15C peak discharge ? 1000A, 300A per cell.
 
And is it possible to replace a single cell when one is faulty ?
And if you replace it, are the tabs still usable ?
 
New email update from victpower..... They also made similar discount for the 48 volt packs.

"By the way, we will do the discount in 15,Nov. to 15 ,Dec.
Order than 30pcs, 36v 20ah is US$299 include charger.
Over 50pcs, 36v 20ah is US$267 include charger."

Tempting to sell a Kidney!
 
mikebikerad said:
New email update from victpower..... They also made similar discount for the 48 volt packs.

"By the way, we will do the discount in 15,Nov. to 15 ,Dec.
Order than 30pcs, 36v 20ah is US$299 include charger.
Over 50pcs, 36v 20ah is US$267 include charger."

Tempting to sell a Kidney!
Click to expand...

They sell other stuff than your standard A123 packs from Fisker.
Are you being quoted for their duct taped pack?
http://www.weiku.com/products/13533142/Lifepo4_36V20AH_battery_pack_with_BMS_and_charger.html
 
http://www.evtv.me/vidarch.html

These guys have interessting video's also a DIY A123 build and info about the complete 28s3p Module.

But at the video of 17 Aug 2012 from about 17.00 Minute
http://www.evtv.me/vidarch.html

It seems that these A123 Cells also can burst into flames, I though they would never go into flames, but maybe it got a way way to high overcharge ?
Also a Burning Fisker with A123 Cells
 
I bit the bullet and ordered 7 of these. $2566 delivered to Orlando FL USA
 
Your a good man!! This will make good reading.
Did you se the thread on the BMS some one made as a perfect drop-in replacement for these packs?
Think it was peter perkins
 
Today I got my 28s3p pack from victpower, packed in foam, but for it's weight the foam is way too soft I think, a pack of 50 kg with sharp edges may not be dropped with 1 or 2 layers of foam. Anyway I got my pack with some dents but hopefully the cells won't suffer from it.

All cells are 3,2 V so that looks ok.

On both sides is a BMS, but as we know, we can not use that.

The bad thing is, based on pictures I saw on the internet I thought the pack would have the balans wires connected to the cells, but at my pack the balans wires have been removed, as far as I can see now I think I can solder new balans wires to the cells, because there is tiny bit of solder left where the original was.

The whole bottom of the pack is dirty with some white stuff which looks and feels like it is cooling paste.


imag0556sc.jpg


imag0554i.jpg


imag0555c.jpg


imag0553c.jpg
 
Bazaki said:
The bad thing is, based on pictures I saw on the internet I thought the pack would have the balans wires connected to the cells, but at my pack the balans wires have been removed
Click to expand...

That is both frustrating and bizzarre, all of mine had balance wires. Seems as the BMS might be less effective without them. The good news is that all cells stayed balanced without the BMS, all of my 28s packs have a cell that self-discharges faster than the rest. If your pack was rejected simply because of the missing balance wires instead of a drifting cell-group, you might have the best one yet! :mrgreen:

-JD
 
Does anyone have a p/n for the plug to match the 7 cell connector going to the BMS?
 
I found the one for the 28 cell, but couldn't find the one for the 7 cell
 
Has anyone ordered/ received these in a while? I'm wondering if stock is depleted, or if it's worth still taking the chance.
 
grinds their still selling them- but if you read over the thread and look at the videos vy evtv etc.... you'll see their not worth it for alot of us- you might get a good module you might get garbage- it seems to me that every module seems to have a cell or few with lower self discharge than the others- which means you have to tear this thing apart and that will not be easy at all- these are not serviceable
 
I received 7 of the 7S3P modules about 2 weeks ago. They all came at 3.3X volts. 3 had the A123 BMS still hooked up, 4 with none. One pack had all the balance wires removed. So far 2 packs have had 1 dodgy cell. I have run any discharge checks yet to see how bad they are, but on one module the cell came up to 2.65 way before the rest, and on the other the one cell took way longer than the rest. I am going to run a few cycles on them and see if they behave or if I will need to do surgery. I plan to run 6 of them as 3 module in series for 75 volts and 2 parallel for 120 AH, approx 9 KWH. So I have one spare module. Although, If I don't get the range I want, I will order 3 more to get to 180 AH.
 
Nice Drewjet. I'm thinking about using a very similar configuration. 21s 3p or 6p for my electric ninja project. Keep us posted, I'm very close to putting in an order...
 
davec said:
grinds their still selling them- but if you read over the thread and look at the videos vy evtv etc.... you'll see their not worth it for alot of us- you might get a good module you might get garbage- it seems to me that every module seems to have a cell or few with lower self discharge than the others- which means you have to tear this thing apart and that will not be easy at all- these are not serviceable
Click to expand...

why do you have to take the pack apart if one cell has a slightly different rate of self discharge? i don't understand why you told people they have to take the pack apart. all cells have slightly different self discharge rates. that is why you have to use a BMS to balance the pack with a bulk charger.

i really do not know why you made this declaration that the packs need to be taken apart. this is just misinformation imo.
 
For the price, if I have to perform some surgery, I'm OK with that. I would get an extra module or 2 for parts.
 
you would have to tear it apart IF you needed to repair it, but if the self discharge of a single cell in a 3P group is not major, there is no need to repair such a pack, but you do have to monitor it if it's not used regularly.

If the group is loosing an amp hour per day, then yeah, it would have to be cut open. but a few mah per month is no problem.
 
Exactly my point. I don't expect a full 20Ah out of the cells or a full 2000 cycles, but by my estimation so far, the price and performance is still worth it compared to nearly anything else I can get my hands on. Plus the additional packaging which is included might make my life alot easier.
 
but there is not any evidence to support your view that you will have to take the battery apart. just a stream of misinformation.

even if the cell voltage drops, that is not clear evidence that the cell is self discharging at a higher rate than the others.

you would have to measure how much charge is lost by recharging to fully charged, then bench testing the cell and establishing the total capacity in order to determine the rate of self discharge. nobody has done anything like that here, or even has a clue how to.
 
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