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

SlyCayer said:
Got my pack today, Lo freaking L, the packaging was non-existent and the ply box had useless wood attached to it, pictures coming later tonight....
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Was there more than one module in a single crate? :?:

So far, that seems to be a real problem, when more than 1 module is in a wood crate it overloads the wood to properly support more than one 7s3p. It will be interesting to see if they will change their method of crating the modules, and, perhaps, one 7s3p module per crate is best. Crating one module per crate will prevent the modules from damaging each other & "overloading" the crate, hopefully, preventing it from bowing & distorting the wood stressing the modules & cells out of alignment.
 
Here is the packaging part, sorry for quality... Iphone 4s ain't the best.

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SlyCayer said:
deVries said:
Was there more than one module in a single crate? :?:
Click to expand...

Yes, only 1, but it looks good tho, the packaging is just none-existent.
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That one picture is very strange with all the layers of wood? :?: What was the purpose of all the layers of wood? :?: :lol:



It does look that ordering One Module per One Crate will get the best results for safe shipping. :idea: :D
 
deVries said:
That one picture is very strange with all the layers of wood? :?: What was the purpose of all the layers of wood? :?: :lol:
Click to expand...

If I recall, they used those as shims to keep the battery from sliding around inside the box (for whatever that's worth).
 
drgrieve said:
Charging LiFeP04 basics.

There is a formula called CC/CV to charging these batteries. You can't pick and choose what parts of the formula is easiest - it doesn't work that way.

To charge to 100% you should charge at 3.65v at a constant current until cell or module voltage is 3.65 then decrease current holding voltage at 3.65 terminating charge when current is 0.05C (3 amps on 60h). After settling (24 - 36 hour period) the resting voltage will be 3.4V. This is 100% charged.

My main issues with some of the recent comments is as follows.

1. If you are charging at 2 amps you are below 0.05C already and you should charge to a lower voltage otherwise you are over charging.
2. Charging LiFeP04 batteries is NOT excessively lossy, you should get back 99% of the energy you put in. Counting AH is an effective way of measuring SOC if you know your starting reference.
3. A cell resting at over 3.4V is OVER charged and likely suffered a small capacity drop.

Note [except for capacity testing] I recommend charging so that the resting voltage is 3.33 or 3.34 for extended cycle life. Replace 3.65 with 3.5. Also even when testing capacity 2V is too low (not much room for error!), aim for 2.5v when capacity testing as ah between 2.5V and 2.0v is minimal.
Click to expand...


This is a noob that's used to dealing with high parasitic loss LiFePO4. ThunderSags, ping, deadways, etc.

Set a current limited supply to 3.65v/cell and forget about it. You don't have to turn current down, it's a natural effect of cell voltage being close to the power supply max voltage (current can only flow when you have a voltage imbalance across a resistance to make it flow). You can't overcharge LiFePO4 at 3.65v, and cells that have good solvents won't have any dissociation effects being left at 3.65v over time (unlike other blends being left at 4.3v etc). Good LiFePO4 (like A123) will stay at 3.65v for months resting.
 
A123 recommends float charging their cells a 3.4V (actually they say charge them to 3.6V then float them at 3.4V). My testing shows about zero capacity difference between 3.4 and 3.6V, you just get to the fully charged state a lot quicker a 3.6V
 
njloof said:
deVries said:
That one picture is very strange with all the layers of wood? :?: What was the purpose of all the layers of wood? :?: :lol:
Click to expand...

If I recall, they used those as shims to keep the battery from sliding around inside the box (for whatever that's worth).
Click to expand...

a wood box is better than a cardboard box ... :wink:
 
Ypedal said:
a wood box is better than a cardboard box ... :wink:
Click to expand...

Agreed. I don't think it would be possible to use cardboard for these heavy modules. No way.

I am just observing & referencing that one pic that I put in my original post... check it out... all the layers of wood on one side... anyway, these were probably just spacers or "shims" instead of using Styrofoam or air bubble spacers, but it is a confusing pic to me, especially, when compared to another photo that shows the module fit very tightly within the crate... and, you don't see all that spacer/shims layers of wood or how those could even fit within that tight-fitting crate. I don't see how those layers could even be used in that other photo that SlyCayer posted. You have to compare those two photos to understand what I'm getting at... :idea: :wink:

After looking at that photo again I see SlyCayer wrote: "the ply box had useless wood attached to it"

It seems this many layers of wood might also have been used for the outside bottom of the crate underneath the module to give some crazy support to the bottom/floor of the module. :?: :p :D
 
so we're upto post # 23 here
lots of battery pics and chatter
yet no one bothered to test their pack and post results?
isn;t anyone a bit curious if their 7s3p can put out at least 54aH ?
i mean when doc bass did his thread- it was one of the first things he did.
 
I would have already tested it if the modules were 8s3p not 7s.
 
It's now Wednesday almost noon in OZ. :mrgreen:

I expect Sutho will be reporting soon about his 22 modules of 7s3p sometime later today, hopefully! :D

Sutho, we look forward to your initial report w/many details to follow too, hopefully! 8)
 
deVries said:
It's now Wednesday almost noon in OZ. :mrgreen:

I expect Sutho will be reporting soon about his 22 modules of 7s3p sometime later today, hopefully! :D

Sutho, we look forward to your initial report w/many details to follow too, hopefully! 8)
Click to expand...

Received my modules today. They certainly weren't new as promised.....and like others, the packaging was very poor. :(

Of the 22 units:

  • 12 units were in the correct voltage range (around 23V) with minimal damage
  • 6 units have 1 group of dead cells
  • 1 unit has the negative terminal burnt off (shorted)
  • 1 unit has been partially stripped (missing BMS internal wiring, cover, etc.)
  • 2 units are severely damage and would not be safe to use

I have been in communication with Victpower. They have agreed to replace the modules if I pay the freight and return the faulty units.....probably so they can resell them to someone else. :?

I have traded with China for many years. Most of my experiences have been good and the companies I have dealt with have always rectified any problems. We'll see how this company functions.

I believe Xin's intentions were good. Can't say the same about the company's principals. :roll:
 
Indeed. Shipping what is obviously garbage is questionable, to say the least. A few shorted cells in a pack with no visible damage is one thing, but what you describe sounds as if they don't care what they put in the box and are counting on the high shipping costs as a deterrent to returns.
 
Sutho said:
I have been in communication with Victpower. They have agreed to replace the modules if I pay the freight and return the faulty units.....probably so they can resell them to someone else. :?
Click to expand...
I would suggest asking to use photos or Skype & video to show the defective parts. It seems an incredible waste of effort to return what is worthless. Obviously, paying for the return shipping is just too expensive, since these modules should have been in much better condition when shipped. I can understand one or two failures, but this really is ridiculous, imo.

This is very disappointing from my POV. :evil:

How many modules were shipped per crate? :?:
 
Sutho said:
  • 12 units were in the correct voltage range (around 23V) with minimal damage
  • 6 units have 1 group of dead cells
  • 1 unit has the negative terminal burnt off (shorted)
  • 1 unit has been partially stripped (missing BMS internal wiring, cover, etc.)
  • 2 units are severely damage and would not be safe to use
Click to expand...

45% percent Failure Rate!

$283 x 55% good modules = $155 per module new price! :idea: :mrgreen:

Sutho was promised repeatedly that his modules would be new! :shock:

It's definitely a deal breaker for me IF they force you to return defective modules. They need to accept pics or Skype video in lieu of any defective returns. Otherwise, the price needs to be as I suggest above.
 
JRP3 said:
For what reason? We know how they are assembled and what's inside.
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Are the cells glued or adhered to eachother ? or just held together with the straps under compression ?

how difficult is it to seperate the 3P groups... i would have zero need for a 60ah pack.. from the looks of it it's best to order up single cells vs these modules and all the work involved to split them.. if you want 20ah ..
 
Ypedal said:
JRP3 said:
For what reason? We know how they are assembled and what's inside.
Click to expand...

Are the cells glued or adhered to eachother ? or just held together with the straps under compression ?

how difficult is it to seperate the 3P groups... i would have zero need for a 60ah pack.. from the looks of it it's best to order up single cells vs these modules and all the work involved to split them.. if you want 20ah ..
Click to expand...
Unless you want the 60Ah module in 3p, then you are correct that building your own battery from the cells is a better way to go by far!

If they cut the price to $155 per 7s3p module -OR- they don't force you to return damaged modules, then hacking a module might be worthwhile IF one is inclined to hack away! :idea: :p :lol:
 
deVries said:
I would suggest asking to use photos or Skype & video to show the defective parts. It seems an incredible waste of effort to return what is worthless. Obviously, paying for the return shipping is just too expensive, since these modules should have been in much better condition when shipped. I can understand one or two failures, but this really is ridiculous, imo.

This is very disappointing from my POV. :evil:

How many modules were shipped per crate? :?:
Click to expand...

I am pretty confident that most of the damage occurred prior to them being packaged :? Some have evidence of being dropped on one edge which pushes the cell divider plates, and the pretty much the whole module, out of alignment.

They were packaged 2 modules per crate. Some crates were well in tact and hard to open. Others fell apart.

I have started adapting new BMS nodes into the good modules and hope to have a charged, monitored pack (or half-a-pack) in a few days.....
 
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