72V 45Ah, gen2 Leaf module - First battery build

MACK

10 mW
Joined
Apr 29, 2020
Messages
20
Location
Tucson, Arizona
Hello all, starting a thread for the battery I’m going to use to power my conversion of an old Honda motorbike that I’ve added a QS 4000W V3 16” hub motor to. The controller I will be hooking it up to is a KLS-7245N rated at 350A, but I realize from my reading that I probably won’t be able to pull all that. While I have the basic understanding and much interest in battery building, it’s not what I would call a comfort zone for me (yet!).


The Plan: I have received 10 gen2 Leaf modules, all tested with ratings from 45 - 46+ Ah capacity, and I plan to connect them in series which would give a bit over the 72V I’m looking for. I have end plates on the way to add to the rod, nuts and washers I have holding them together, to apply the appropriate pressure as I’ve learned about (I’ve been through the large, but chock full, leaf module test thread). I also plan to add a BMS…probably. The arguments against esp with these cells is temping, but I know I can get lazy.

modules.jpg


So for my first test in understanding series and parallel, if the modules are each 2s2p and I hook the 10 up in series I would have a 20s10p pack, yes?

Other initial questions include the material for the connecting bar/plate,besides copper I've seen various steel looking connectors. How about aluminum bar? I know it’s used in fuse/breaker boxes as the buss bar and connections to copper, and I’ve got it. I do have some ¼”copper tubing that I flattened for consideration, then the question occurred of what size is appropriate for the voltage, would I need to double up the copper pipe? I know end wires out are full voltage how about in between modules (I’m thinking so)?

copper.jpg



I’ve made a cardboard mockup of the complete battery to plan out a box and the frame and connections.
I’ve got more questions (like charging and actual voltage?) but I think they’re a little further down the road, . Please let me know other thoughts, or things to consider for this build that I might not have.

Thanks
 
So for my first test in understanding series and parallel, if the modules are each 2s2p and I hook the 10 up in series I would have a 20s10p pack, yes?....
NO ! Each module is 7.4 v (2s, 2p)...So 10 in series wil result in a 20s, 2p pack.
PS..those are not “Gen 2” modules which were much bigger with 8 cells in each module.
And the Ah rating is strange..
The leaf has had 3 different cell types.. 30Ah, in early 24kWh packs
..41 Ah in the 30 kWh pack
..56 Ah in the 40kWh pack (8 cells per module)
But your 46Ah results are none of those ?
......unless that is a result from the 2p x30 Ah module , IE:- 76% capacity of a 60Ah pair !
 
Hillhater said:
NO ! Each module is 7.4 v (2s, 2p)...So 10 in series wil result in a 20s, 2p pack.


Ah, I get now, thanks, -no better way to learn then making the wrong choice out loud :thumb:


Hillhater said:
......unless that is a result from the 2p x30 Ah module , IE:- 76% capacity of a 60Ah pair !

Yes, I believe so, I purchased them from Greentec auto who tests each module (4cells 2s 2p) for current (todays) capacity, marks it on them (can see the stickers to the right of the contacts in the original pic) and ships batches that are within ~1Ah of each other. They refer to them (as well as others) as gen 2 with 1 being the original sardine can, and I figured the double module - 8cell version was 3?

40559505_551348498612902_5285765789616439296_n.jpg


I know there is also what's call the lizard pac which was an early update(?)

Either way I have the module that is pictured in the middle above, what they call 2013/2016, that were recently tested for the 45-46Ah rating.

Thanks!
 
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