Nissan Leaf Cells Test Data

[blisspacket]

Maybe this will work for fotos:
http://jpbliss.smugmug.com/organize/Boats/Leaf-Battery/i-MnwZHWP

 

[Hillhater]

...the inner "diaphragm" of each module has about 1/16" of airspace between the top surface of one module and the bottom surface of the next.

?? so are you saying there is not actually any contact (or compression) between the surfaces of each module in a "static" condition ??

Maybe this will work for fotos:
http://jpbliss.smugmug.com/organize/Boa ... /i-MnwZHWP

What is this for ?
If you have hosted photos there..it needs a password !

 

[blisspacket]

Still trying with fotos.
http://www.smugmug.com/gallery/n-zWgHk

To answer Hillhater: there's 1/16" space in the middle. At the two ends of each module, where the spacer bars go, everything's tight up against. The holes in the modules have compression tubes so's not to collapse the module.

You'll see a dime-size bit of modeling clay in one foto on the endplate. That's the gap--1/16--that appears to prevail.

 

[Giovanni LiCalsi]

Thanks for the photos.
Can you tell me what the length of the battery pack that is standing on edge?
I estimated somewhere around 34.5".
I'm assuming that there are 24 battery modules in the row.

 

[mvly]

I might need some more nodules. Any way to get a hold of these at a reasonable price?

 

[cassschr1]

What do you consider reasonable ?

 

[Giovanni LiCalsi]

The modules are as low as $100.00 each at the wrecking yards.
You will be able to find used Tesla motors, with all of the Model S sedans out there.

 

[Hillhater]

To answer Hillhater: there's 1/16" space in the middle. At the two ends of each module, where the spacer bars go, everything's tight up against. The holes in the modules have compression tubes so's not to collapse the module.

You'll see a dime-size bit of modeling clay in one foto on the endplate. That's the gap--1/16--that appears to prevail.

OK, so to be clear.. it would seem that the spacers, end plates, bolts, etc, ..form part of a structure to support and protect the modules, and are in fact designed so as NOT to compress the actual cell pouches. ?

 

[Giovanni LiCalsi]

Yes. These module cases are very similar to an aluminum sardine can and can easily be crushed in an impact.

 

[Hillhater]

Yes. These module cases are very similar to an aluminum sardine can and can easily be crushed in an impact.

Obviously, but my point was that these packs are deliberately designed NOT to compress the cell pouches, where as some other cells require compression in order to function correctly ( EG:- A123 )

 

[icecube57]

When I dealt with them i dont think the cells were under compression. I stated that when I did heat shrink them which did compress them that they gave more capacity.

 

[Giovanni LiCalsi]

Here you can clearly see how the pouches are not in compression and how the internal module corner frames protect the pouches.

 

[Arlo1]

Here you can clearly see how the pouches are not in compression and how the internal module corner frames protect the pouches.

Doesn't look like... But the cutaway might have been done in a way that they didn't want the sharp edge against the pouch...

 

[999zip999]

How big of a pack are you building 24s 60amp. ?

 

[mvly]

Reasonable is $100 per pack. But again that is used packs so my guess would be $150 for new would be reasonable price for these cells.

I have tested them on my ~110lbs bike and I can realistically pull 25Ah out of it at around 1-2C. Note that I do not fully charge it or fully drain it either. I usually charge to 4.15V and stop around 3.71V. Last time that gave me around 25Ah. Again I am using it mostly at 1C but occasionally up to 1.5 or 2C.

Maybe I can get an extra 2-3Ah if I fully charge it and fully drain it. But these cells in my opinion are over rated. No way are they 30Ah cells.

The voltage sag is still in check. I am running 24s and it sags to around 93V at 2C from close to fully charge.

But most of the time it is above 90V even for hard acceleration for most of the ride until I am around 40% where it begins to sag below 90V around 50A battery current.

Overall I like it so far because it seems to be good in term of aging. Even in the cold it is still giving me solid 25Ah with a bit more voltage sag. It performs as the day I put the cell together. Since then I have put around 50-60 cycles on the battery.

 

[mvly]

From the image of the aes battery, it looks like it is NOT the same Nissan pack because it is 3 cells vs the 4 cells in the leaf pack. Just FYI for those who don't know.

 

[blisspacket]

Giovanni, the length of the 24-module stack is 32.5" endplates included.
Because there are compression-prevention aluminum tubes within each corner of each module, you're not actually compressing the module, just containing it. The center of the top of each module is indented, and that seems to provide for a "breathing" surface, but I suspect it's nothing end-users like us really need to worry about. We just accomodate for it. Probably on a massive 240v charge in the original package that space is necessary--I'm outta my league, and just guessing here.

 

[Arlo1]

From the image of the aes battery, it looks like it is NOT the same Nissan pack because it is 3 cells vs the 4 cells in the leaf pack. Just FYI for those who don't know.

The picture has 4 cells. You can see it from the tabs at the tops of the cells on the right.

 

[Giovanni LiCalsi]

Yes. You are correct.

 

[Hillhater]

Maybe I can get an extra 2-3Ah if I fully charge it and fully drain it. But these cells in my opinion are over rated. No way are they 30Ah cells..

Obviously you are setting you own standard here.
Most cells are rated at 0.2C discharge ( These at 0.3C ?) for some reason , but it appears to be the "industry standard procedure".
Several others have tested these cells and reported 30+ Ahr.
I am certain they are not the "ultimate" EV cell, but they appear to be reliable, have good packaging and easy connection features, and are available at reasonable prices ( $125 per module of 4 cells)

 

[Giovanni LiCalsi]

It would make a very efficient EV using 24 Leaf modules in a http://www.vintagespyders.com
The ready to drive ICE version only weighs 1250lbs. It could even be better using an Alulight monocoque chassis.
An AC50 motor bolted to a Borg-Warner EV transaxle would create enough space for 24-48 a Leaf battery modules.

 

[mvly]

Here are the videos on how I disassemble them and wired them back to a 24s1p.

It's long, but it shows the full process.

1. http://www.youtube.com/watch?v=WcqaAz1vjlo
2. http://www.youtube.com/watch?v=VeTxXkBAc60
3. http://www.youtube.com/watch?v=J3kbQPb_kbA
4. http://www.youtube.com/watch?v=PypX2PQGzuc

How you guys mount it is up to you!

 

[cassschr1]

Thanks Larry for posting. I reviewed them all.

 

[MitchJi]

Hi,

Is it possible/easy, without taking the Modules apart, to use them as 1s,4p?

 

[cassschr1]

Harold in CR is going to try that.
I've taken 4 apart . Completly though.
If trying to leave cells together, you're going to need to remove the top 1" of the can,all the way to approx 1" from the edges. Then get creative on figuring how to complete the series wiring.