# Leaf Modules - Gen 2



## Kevin Sharpe (Jul 4, 2011)

I've been stripping down some "Gen 2" Leaf Modules and thought I'd share the details because they are a lot easier to work with than the older "Sardine Can" design.

I'll start with some photo's and add more details over the next few days


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## Kevin Sharpe (Jul 4, 2011)

Note that you can separate the outer aluminium 'skin' using simple tools, no need to cut anything. Separating the aluminium 'skin' from the insulator protecting the cell pouch takes some time because it has strong adhesive.


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## Kevin Sharpe (Jul 4, 2011)

Not much weight in the skins and spacers...


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## Kevin Sharpe (Jul 4, 2011)

Nissan no longer have modules that swap the positive/negative terminals around, but they do have some with additional mounting hardware (12 of the 48 modules in the battery). This hardware can be easily removed although it could be useful for improving battery rigidity...


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## Caps18 (Jun 8, 2008)

Pretty interesting. I have taken apart the first gen LEAF batteries and have all the pieces on the floor. I'm not removing the aluminum shell though.


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## electro wrks (Mar 5, 2012)

It looks like to me the way the Al shells are bonded to the pouches, the shells may be important for heat transfer (both heating and cooling) in the battery pack. Do the adhesive patches look like they're made of a heat conducting material? If so, it may be something to think about if the pouches are used without the shells.


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## Karter2 (Nov 17, 2011)

Any test/performance data from these cells ?
Much change to the earlier type. . 
Capacity ?
DCIR. .?
Discharge plots ?

PS:... Have you tried the drop of Isprop Alcohol trick, to separate the glue from the shells.

Oh, and thanks Kevin for posting these pics ...very interesting.


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## Kevin Sharpe (Jul 4, 2011)

electro wrks said:


> It looks like to me the way the Al shells are bonded to the pouches, the shells may be important for heat transfer (both heating and cooling) in the battery pack. Do the adhesive patches look like they're made of a heat conducting material?


The adhesive is not a heat conducting material and nor IMO is the 'plastic sheet' which I tested with a heat gun on one side and my hand on the other 

It's clear from the pack design that no active cooling/heating of the modules is undertaken in the Leaf. I'll include temperature measurements when I test the cells.


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## Kevin Sharpe (Jul 4, 2011)

Karter2 said:


> Any test/performance data from these cells ?
> Much change to the earlier type. .
> Capacity ?
> DCIR. .?
> Discharge plots ?


We've produced no test data but I'm happy to run any tests that people would find useful. If you have a particular test setup or process let me have the details.



Karter2 said:


> PS:... Have you tried the drop of Isprop Alcohol trick, to separate the glue from the shells.


Worked like a charm... thanks!




Karter2 said:


> Oh, and thanks Kevin for posting these pics ...very interesting.


No problem... happy to share... were seeing ~3 Leaf's a day at auction in the UK so only a matter of time before these modules get really cheap


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## Karter2 (Nov 17, 2011)

Kevin,
I could not see from the previous photos, but what are the internal cell connections like ?
Welded ?, crimped ?, screw clamps ?. .??
Does it look feasible to re terminate a module to be 4S, 1P without major rework. .?

PS: I read the 2016 leaf will have a 30kWhr pack with modules of 4S,2p , presumably with 40Ahr cells?

http://insideevs.com/2016-nissan-leaf-107-miles/


> As for the actual pack structure, the original 24 kWh battery is made up of 48 modules composed of 4 cells each, for a total of 192 cells. *The new 30 kWh battery has double the cells per module (8), but still 192 cells in total. *Nissan once again points to automotive-specific battery formats as a superior commodity.


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## Kevin Sharpe (Jul 4, 2011)

Karter2 said:


> Kevin,
> I could not see from the previous photos, but what are the internal cell connections like ?
> Welded ?, crimped ?, screw clamps ?. .??
> Does it look feasible to re terminate a module to be 4S, 1P without major rework. .?


Here are some photos of the internal cell connections. I believe the tabs are cold welded to copper strips and IMO it does not look impossible to rewire the cells internally


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## Yabert (Feb 7, 2010)

Ultrasonic welding. Nice!
Similar to the welding on chevy Volt cells and on some good electric motors.

Thanks to share Kevin.


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## Kevin Sharpe (Jul 4, 2011)

Karter2 said:


> PS: I read the 2016 leaf will have a 30kWhr pack with modules of 4S,2p , presumably with 40Ahr cells?


I believe the new "Gen 3" module is simply using two of the "Gen 2" style modules stacked together but with a higher capacity cell... I'm investigating a 4 module stack to save a little weight and thickness 

One of the things I like about the Leaf battery's is that we already have three cell capacity's to choose from


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## Kevin Sharpe (Jul 4, 2011)

No room for cooling/heating at the module level (and none included in the battery pack)...


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## dcb (Dec 5, 2009)

Kevin Sharpe said:


> Here are some photos of the internal cell connections. I believe the tabs are cold welded to copper strips and IMO it does not look impossible to rewire the cells internally


Thanks for posting, it looks fairly identical to the previous generation, with attendant headaches for reconfiguring for higher voltage.


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## Kevin Sharpe (Jul 4, 2011)

final tally of easily removable parts and stripped down modules (note two different scales in use and while the KERN is calibrated the Salter is not )


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## Karter2 (Nov 17, 2011)

Kevin Sharpe said:


> Here are some photos of the internal cell connections. I believe the tabs are cold welded to copper strips and IMO it does not look impossible to rewire the cells internally


Superb photos Kevin.
Yes , US welded,....or one Mutha of a crimp !
Thanks again.


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## winzeracer (Apr 3, 2012)

Just modeled the Leaf cell. If anyone needs it let me know. Modeled in Solidworks 2015


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## winzeracer (Apr 3, 2012)

I didn't model the guts. I doubt many would need that


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## ekwok117 (Sep 6, 2014)

Oh sweet! I would love the model. PM'd


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## Karter2 (Nov 17, 2011)

Just to be clear,...that is the original ( Gen 1) module , not the Gen 2 being discussed here.


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## Kevin Sharpe (Jul 4, 2011)

some module discharge test results published by bigmouse here;

http://www.diyelectriccar.com/forums/showpost.php?p=685122&postcount=2


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## Kevin Sharpe (Jul 4, 2011)

winzeracer said:


> Just modeled the Leaf cell. If anyone needs it let me know. Modeled in Solidworks 2015


Great work! Would you also model the "Gen 2" module?


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## winzeracer (Apr 3, 2012)

Yes that was the Gen 1 module. Modeling the Gen 2 today, both configurations. When finished I will publish a link for downloading all Gen1 and Gen2 of the Leaf cells. If you PMed me, sorry I had a few finishing touches to add I will respond when all 3 models are completed. On The Gen2 models I did not do all the cosmetic details but all the dimensions that you need for building parts will be accurate.


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## winzeracer (Apr 3, 2012)

oopps sorry wrong info


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## DreamMachine (Sep 28, 2015)

Hate to kinda hijack the thread, but I don't suppose any of you know the dimensions of the complete leaf pack?


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## winzeracer (Apr 3, 2012)

Hey all,

Here are the 3 differernt models I have:

1. First Gen Module
2. Second Gen with Brackets
3. Second Gen w/o brackets

Here are the SW 2015 files, also threw in a step of the gen2 since it was in the folder.

Also a rendering of half a pack (24modules) with the new wireless BMS boards on it. We will have one 24 module pack in the front and back in Jay Leno's 1914 Detroit Electric that we are rebuilding, pretty fun project and every car guy's dream to get to work in his garage. 

Regards,
Brock


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## JCC (Mar 19, 2015)

Winzeracer,

Thanks for posting those CAD models! What bms boards are you using? Do you know of any that fit well with the geometric constraints of the leaf modules?


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## jwiger (Oct 18, 2014)

Brock,

Do you mind if I upload these to Onshape and share them?


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## winzeracer (Apr 3, 2012)

Hi guys,

I have uploaded them to my GrabCad account here https://grabcad.com/brock.winberg-1/projects

The BMS we are using is one that we have developed, unfortunately it is not for sale at this time. It is a wireless system that bolts directly on top of the busbars, no wires for BMS inside battery box

Thanks,
Brock


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## winzeracer (Apr 3, 2012)

jwiger said:


> Brock,
> 
> Do you mind if I upload these to Onshape and share them?


Feel free to upload just give me the Cred In fact the main reason I wanted to upload them was because I found someone that had modeled them and was selling the model for $1200. Robbery I tell you.

Thanks,
Brock Winberg
simplesolutionsinclusive.com


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## jwiger (Oct 18, 2014)

Thank you Brock, they look great!

I've made these public on Onshape, for those of you whom don't have Solid Works, you can make a free Onshape account and do some pretty good CAD stuff. It's like Google Docs for CAD.

Here's the link to Brock's Drawings:
Nissan LEAF Batteries - By: Brock Winberg

PM me your email address if this link doesn't work right.


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## JCC (Mar 19, 2015)

Brock,

Just curious, but did you end up using threaded rods to secure the battery or did you end up doing something different?


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## winzeracer (Apr 3, 2012)

JCC said:


> Brock,
> 
> Just curious, but did you end up using threaded rods to secure the battery or did you end up doing something different?


JCC,

Yes we are going to use the threaded rod, endplates and a couple additional brackets. We are ditching the stock endplates as they are really heavy and overbuilt. 

Thanks,
Brock

Sent from my XT1254 using Tapatalk


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## Scottydog (Nov 4, 2014)

Cool post, has anyone got any idea yet on the dimensions of the Gen 3 batteries yet? Gather will be a smidge slimmer than 2 Gen 2's, just wondering how much? Could make what was not possible for me before, possible!


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## winzeracer (Apr 3, 2012)

If you ship me one I will Model it, ofcourse you will need to pay shipping return too.

Sent from my XT1585 using Tapatalk


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## Matej (Dec 4, 2015)

Scottydog said:


> Cool post, has anyone got any idea yet on the dimensions of the Gen 3 batteries yet? Gather will be a smidge slimmer than 2 Gen 2's, just wondering how much?


It does not appear so. They may actually be slightly wider.


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## agniusm (Apr 30, 2012)

So whats the total weight saving removing aluminium , and the rest from the module not including the mounting hardware? 295g?
Does anyone knows what the Gen2 module weighs? Gen1 was something like 3.8kg


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## Hugues (Jul 13, 2014)

agniusm said:


> So whats the total weight saving removing aluminium , and the rest from the module not including the mounting hardware? 295g?
> Does anyone knows what the Gen2 module weighs? Gen1 was something like 3.8kg


This page seems to be about Gen 2 and gives 3.7g per module and 799g per cell:
http://hybridautocenter.com/HAC4/in...15-64ah-nissan-leaf-battery-module&Itemid=605


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