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nealwallace
27 April 2016, 1927
Im running a 2001 SV650 with the following specs:

ME1003 @ 72v
Alltrax SPM-72400
12 20Ah AGM batteries 6s2p (14.5lbs ea)

The batteries are too heavy and I've narrowed my choices to either custom built Tesla 18660 pack (using actual 3400mAh Tesla cells) or Leaf modules.
With the Tesla Gigafactory on its way to being finished 18650 cells are going to really start flooding the market. My gut is telling me to just build 18650 packs for my motorcycle conversion. Any thoughts on this idea? Ive heard it's tedious but I can handle the mundane. With the shape of the cells I can conform to any build.

Leaf modules look very attractive for the present. 8.4v means fewer modules. The boxes are larger than cells but they are still very compact compared to CALB style cells. Who thinks it's best to just grab the Leaf cells while they're hot and upgrade later?

Any ideas or random thoughts? I'm just stuck in my head about this decision and want to see if I'm missing something. Thanks!


(Had to teach my boy to ride to get better range with 180lbs of batteries!)
http://uploads.tapatalk-cdn.com/20160428/02876fa5995b132bf61b94a53a3d9d04.jpg


Sent from my Nexus 7 using Tapatalk

DRZ400
28 April 2016, 0610
Go with 11 the Leaf cells! Sooo much better than building up a 18650 pack. The performance over your present pack will be astounding! Can supply more then your ME1003 will ask for. I have over 150 cycles on mine, no BMS, all cells balanced within .005v. My next upgrade will be the next generation of ev auto batteries...fresh from the wrecking yard!

mistercrash
28 April 2016, 0816
I am also running Leaf modules and I agree they are a good choice. Super easy to put together and they give good power. But I also am convinced that a well built battery made with Tesla 18650 cells would be even more powerful and much smaller and lighter than Leaf modules. But the build will end up being more expensive. I went with Leaf modules because they are a good bang for the buck, but if I wasn't so poor, Tesla cells would've been my first choice for sure.

nealwallace
28 April 2016, 1110
Go with 11 the Leaf cells!

This seems like the best idea right now, too. How did you manage the 90v limit on the Alltrax SPM controller? (I'm guessing there are 2 options: capping the charge voltage or draining the pack to below 90 after charge.)

DRZ400
28 April 2016, 1123
Simple, I adjust my charger to stop at 90 volts (~4.1/cell). I also set the LVC on my controller to 75 volts. This way I can run without a BMS by avoiding the cliffs at both ends. You give up a little range with less tress on your batteries.

cfscrewed
28 April 2016, 1130
I working on a SV Build too, im going to use 11 leaf cells and a kelly controller :)

DRZ400
28 April 2016, 1156
Kelly controllers do ~ 1/2 their rated value (I had 2). My 400 amp rated Kelly maxed out at 240 amps. My SPM72400 hits 450 amps. BIG difference in acceleration and pull!! On the other hand you can get re-gen and they are very smooth.

cfscrewed
28 April 2016, 1244
Yea, well i had to go kelly due to the use of the ME1119 Motor and the sin/cos encorder and feedback

DRZ400
28 April 2016, 1259
Gotcha!

nealwallace
07 May 2016, 1804
I've weighed all of the excellent advice I received and decided to go with 18650 cells (1,650 2500mAh). I have this long-term vision of making a standard 3s32p and 3s16p "whole-brick" and "half-brick" respectively.

Description


Each "half-brick" will have a self-contained BMS (qty 3), pack fuse, temp sensors, etc.
To make a whole brick we parallel a special half brick w/o a BMS. Each brick is essentially a 12v 40Ah battery equivalent.
Each brick in self-contained enclosure that can snap/bolt in place. (Like a bottle enclosure)


Applications:


Motorcycle: 6 "half-brick" slots.
Lawn mower (push): 3 half-brick slots.
Lawn mower (ride): 4 brick
Go-Kart: 2 half bricks
Car Conversion: 12 whole bricks (or more)


Use
Build a battery cage assembly that resembles mail slots. The slots are already prewired for the series/parallel configurations needed on each brick. All we have to do is insert brick into slot and secure it. DIY Tesla PowerWall? Batteries for camping trip? e-Bike batteries for a quick trail run? Snap some bricks in and/or easily carry a few extras.

Conclusion
Once I nail down a versatile form factor for the bricks I'll start prototyping them.

Thanks for everyone's advice on this. Looking at this project long-term I don't want to rely on the availability of Nissan parts.

nealwallace
16 May 2016, 1827
You guys were right.... I'll post some pics and possibly a video but in conclusion the Tesla built modules have all of the cells epoxied together. There is no practical or safe way to separate the cells. I have 4 modules intact that are 15s22p. Each are putting out 60v right now. I knew this was going to be a gamble. My hope was that the cells could be separated easily and the only hard part would be assembling a custom pack. Now the hurdle is selling these modules so I can recoup something and then head back to the drawing board.

tomdb
16 May 2016, 2320
so you have the "tesla" modules from the Smart electric?

http://www.evwest.com/catalog/product_info.php?cPath=4&products_id=329&osCsid=rvo1bvg93jp94qlq5idklr5fk0

I hope you got them cheaper then they are priced at EVwest, because at that price you are paying 330 dollars a KwH.

Tadas
17 May 2016, 0917
You guys were right.... I'll post some pics and possibly a video but in conclusion the Tesla built modules have all of the cells epoxied together. There is no practical or safe way to separate the cells. I have 4 modules intact that are 15s22p. Each are putting out 60v right now. I knew this was going to be a gamble. My hope was that the cells could be separated easily and the only hard part would be assembling a custom pack. Now the hurdle is selling these modules so I can recoup something and then head back to the drawing board.

It's not so hard to separate the cells from tesla pack..I lost just 4-5 cells from 2 tesla packs.Yes it takes time yes you should be acurate with it but it could be done.There is no need for expensive tools just patience.If you are interested let me know I will try to explain how to do it.There is other question is it worth to go with tesla when you can get Leaf packs.My Answer is NO.

billmi
09 September 2016, 1059
I ran across this recently, and have only fast-forwarded through it. I need to watch the whole thing and the related videos, but it looks like he's using 18650s out of used laptop batteries for home power storage (a'la Powerall) on the cheap. https://www.youtube.com/watch?v=Bk50IuWXg-c

tomdb
09 September 2016, 1200
I would not listen to Jehu too much. He does not really get some of the concepts when it comes to electric cars/electric batteries. Plus too much "drama" or opinions in his videos.

However again, 18650's too much a pain to assemble when leaf or volt cells are that cheap.

blisspacket
13 September 2016, 1805
Another consideration that I think gives points to the Leaf: in the Nissan build, the batteries sit in a bellypan with no a/c, no venting, yes there's a Detroit latitude warming blanket, but otherwise there's safety and durability built into the battery chemistry. I have blown up some 18650 cells (no I don't know why they fired off in a Makita charger). Out of 30 Leaf modules, I've had one get warm on me and belly out the container, and I don't know what I did to make that happen. The other 29 continue to power a boat and a lawnmower. They're well behaved.