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Discussion Starter · #1 · (Edited)
Hi guys,

Built this bike some years ago,pics here: https://www.facebook.com/zvexx.motorbike/

I'm running on 26 Leaf cells, first gen bought in September 2014, they were supposed to be new. Been riding since spring 2015 with them, never had any problems. The 26 cells are paired by 2, then the 13 pairs are in series. I can pull 600 amps peak without too much strain.

Now, after 4 years, my range has reduced somehow, not catastrophic, but there are days I would like to ride longer and pull hard on pack.

So I'm thinking about installing new batteries next winter, starting in October.

What are my options in 2019 ?

I attach a picture showing how my pack is built, with dimensions.

The least amount of work for me would be to buy new Leaf cells and just swap them. I saw some here (and they seem to ship abroad, I live in Switzerland):
https://greentecauto.com/hybrid-battery/nissan/lot-of-5-2012-nissan-leaf-battery-module-7-6v

But if these are not new, i might end up with not so much more range than currently.

I would be ready to redesign the pack if i could get a significant increase in range (and not loose on peak power, i need to pull 600 amps for a second or two).

Would this Tesla module make any sense ?:
https://greentecauto.com/hybrid-battery/repurposed-batteries/tesla-model-s-battery-cells

At 25 V, I would need 4 to reach my current voltage of around 100 volts. That would be 21 kWh, that would be awesome, compared to my 13kWh when my Leaf pack was new. They don't rate max Amps of that module, I guess they can handle 600 amps for a second or two ?

Any other options ?
 

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I'm running on 26 Leaf cells, first gen bought in September 2014, they were supposed to be new. Been riding since spring 2015 with them, never had any problems. The 26 cells are paired by 2, then the 13 pairs are in series. I can pull 600 amps peak without too much strain.

...

I attach a picture showing how my pack is built, with dimensions.

The least amount of work for me would be to buy new Leaf cells and just swap them. I saw some here (and they seem to ship abroad, I live in Switzerland):
https://greentecauto.com/hybrid-battery/nissan/lot-of-5-2012-nissan-leaf-battery-module-7-6v
As the linked page says, what you are calling "cells" are actually modules, internally configured as a 2S 2P set of four cells; each cell is about 3.75 V and ~30 Ah, so modules are 7.5 V and ~60 Ah. That makes your original pack about 98 V and the 13 kWh that you mentioned.

I only mention this because it could be confusing if anyone thinks you are actually using only 13 cells in series.
 

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Would this Tesla module make any sense ?:
https://greentecauto.com/hybrid-battery/repurposed-batteries/tesla-model-s-battery-cells

At 25 V, I would need 4 to reach my current voltage of around 100 volts. That would be 21 kWh, that would be awesome, compared to my 13kWh when my Leaf pack was new. They don't rate max Amps of that module, I guess they can handle 600 amps for a second or two ?
First, the ad says 24 V and it's actually 22.5 V nominal, like any other 6S module of similar lithium chemistries. I don't know why people want to call them 24 V... they're not lead-acid batteries. You are currently running a 26S configuration, so four of these Tesla modules would be 24S and a bit lower voltage - maybe not a problem at all.

These are the modules of the 85 kWh Tesla model S, which have 16 of these modules. 600 amps through 16 of these modules at nominal voltage would be 216 kW... and yes, that's well under the commonly quoted battery power for any 85 kW Model S so 600 amps (for at least a few seconds) must be possible.

While the Leaf modules are designed to be stacked directly against each other (and actually need stacking and end plates), the Tesla modules cannot physically sit on each other - you would need to build a framework to hold them close together but not supporting each other. The Tesla modules also require circulating coolant to manage heat distribution among the cells, unlike the Leaf modules which have more modest performance expectations and do not have cooling provisions. Most other production EVs use modules which are clamped down to "cold plates" with circulating coolant in them.
 

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Discussion Starter · #5 ·
thanks guys,
seems the new Leaf modules could be the best option, more range without me having to redesign the whole system.

I checked the size of the Tesla modules, they are too long to fit 4 of them, i could fit 2, so around 10 kwh for ~50 volts, definitely not worth the work. I would need to fit 4, but this is a major overhaul of the bike.
 
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