Plan to build a 10345 cell-based wall - opinions needed

eAnic

eAnic

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Mar 20, 2017
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Hi,

i have thoughts to build a 10345 (flat cells) based Powerwall.
Why?
- i'll get them cheap
- they are nice and small
- already fused and can be spot welded
- it's something special andnew looking onto all these 18650s based concepts

My plan is to combine them into a 7s24V Pack and to support the grid at night
from solar energy gained over the day.

What are your opinions on this plan? It looks, i have several topics to solve, e.g.
grouping them together (do holders exist for these babys?)
They also tend to expand when they age, so my holders have to digest that.
 
Do you have link where you would buy them? Or are they local? This is a new cell format to me. Is it kind of like a bulky prismatic cell? Pictures?
 
Have heard of and used 10440 in torches, maybe this is the unprotected version, are they similar size to a aaa alkaline?
 
Korishan said:
Do you have link where you would buy them? Or are they local? This is a new cell format to me. Is it kind of like a bulky prismatic cell? Pictures?
Click to expand...

I can buy them in spare laptop batteriesfrom a reseller.
These are the cells inside the packs:
https://www.alibaba.com/product-detail/Prismatic-Li-ion-3-7V-103450_1268386192.html

Mostly Sanyo 1900mAh and also Moli 1900mAh cells.
I already buyed some of them. Many were between 2-3 Volts when buying them.
Some are loosing capacity but lots are holding the voltage stable.
Capacity of some cells testet is between 1600-1800 mAh.
 
When I made ebike packs I deliberately left a little slack in the fuse wires when soldering to the bus in order to allow for movement due to vibration. You could do the same thing with those cells to allow for expansion.
 
Just a side note related to why we are using 18650s now... At some point the industry figured out that an 18650 cell (18mm diameter by 650mm in length) was the optimal size for wrapping up the plates inside a single cell and allow a 1C - 5C charge and discharge rate. I looked into this because I was wondering why massive batteries like Tesla (up to 100KW now) were using such small individual cells.

However, as many know, Tesla has been working with Panasonic for many years to provide the next gen cell. They have recently decided that the next gen cell will be solid-state and in a 21x700mm package. They are calling it a 2170.

So in 5 years or so we will all be creating new packs with 2170s, once the used cells start hitting the market :)

but for now, we use what we can get. Just keep in mind that the flat pouch-type lipos are a bit more vulnerable to certain environmental factors.
 
Interesting this topic should arise , I've just been testing some old cell phone flat cells that I've had lying in my junk box for years ... they are about the same weight as a 18650 and these old discarded cells have a capacity over 1AHrs still in them (after charging)!!!
This opens up a whole new universe of possibilities ... powerwalls built from discarded cell phone batteries!!!

They are more numerous than laptop batteries ...and probably a lot cheaper scrap price..... my investigations continue .

I think these flat cells are generally Li- polymer (although eAnic's are Li -ion)...the 18650's are Li -ion .... Li- polymer are used in radio control planes and helicopters handling high discharge (20C) without problems.
 
ok a small update...

I got 24 Packs with 192 cells so far. My procedure was to get them out, cleaned and charge up to 4,2V.
All cells above 2V have been charged with 500 mA, others with 200 mA.
Then i let them sit for ~2 weeks and checked the voltage again.
Cells with a voltage above 4,14V went into my discharge test.
Cells above 3,9V got a recharge and were checked again after a week.
Cells below 3,9V have beendiscarded.
I'm not sure if this is the correct method to determine the health state but i liked this method.

Since the cells have a nominal rating of ~1900 mAh when new, i consider anything above 1000 mAh
as usable.
154 cells > 1100 mAh (A+, A and B rating by me);122 cells are > 1500 mAh(A+ and A rating by me)
Rest is unusable because they are blown up and do not hold the charge. I'm also very strict and kick them out if
they drop from 4,2V to 4V within 3 weeks.
This makes a success rate of 80percent. Is this bad or do you have same success rates?

This is a really hard and time intensive work. But i must be sick because i love it! :p

(more packs -around 200 - are on the way to me, so i have toprepare myself for a long and hot summer project)
 
I have sucess rate of 45% here on laptop cells.
That is min drop 0.1v and 2Ah or more.

Above rate is based on random packs. Packs i bought on bigger occassions and such have sucess of above 80%
 
@eanic hey I have 8pcs hp tv08extended battery packs 8 cell each with the Sanyo/moli cells. Bought 10 originally thinking they were 18650, oops, opened 2 up 1 had Sanyo the other moli so I'm guessing the rest are a mix of both. I played with them a few months ago but from what I remember 2 or 3 cells out of 16 were bad the rest were over 1Ah I
I was planning on throwing them in ebay but if you're interested, let me know.
image_idaxzc.jpg
 
Let me know as well , I have quite a few that I'm not going to use and considered eBay as well but would rather someone on here have them if needed. PM me for details if you're interested.
 
Hello,

i'm interested for further 10345 packs but i think shipping from US to Austria (not Austrialia!) would ruin the whole calculation. But thank you anyway :)

But first of all i need to discover a simple and cost effective mount for my packed cells.
Buyable holders do not exist and i have no 3d printer...
 
eAnic said:
Hello,

i'm interested for further 10345 packs but i think shipping from US to Austria (not Austrialia!) would ruin the whole calculation. But thank you anyway :)

But first of all i need to discover a simple and cost effective mount for my packed cells.
Buyable holders do not exist and i have no 3d printer...
Click to expand...
Hello eAnic,

I am also new around here and deaing with prismatic cells. I am using these because I get them for free... in small numbers but hey, it is a start...
I will prepare a post in the coming days explaining how I am doing it, but I keep the cells inside their plastic case, cut out the part where the PCB is, get rid of it, and so exposing the cells' terminals. Since all batteries are the same so far, the terminalls allign nicely and it will be quite easy to connect them to a buss bar. Here is a picture of how they look


image_ugtemt.jpg


what you see is a 3S16p arrangement. At an average of 3400mAh, it is about 600Wh.
I am planning to hold them together with a long threaded bar (dont know if you call it like that... it is like a long screw without head), bolts to get the right spacing between cells and 1mm thick Al plates. hmm... I think it is difficult to see... lets draw it!


image_hvsmip.jpg



image_zydilb.jpg


For now it is only an idea, but I think it should work... cheap materials and I can use metal objects since the cell are inside their original plastic case.

Anyway, I hope you find it interesting and perhaps inspire you in some way!

Cheers
 
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