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Project:Bike|Batteries

A project log for 2002 Suzuki SV650e

2002 Suzuki SV650 electric conversion

NealNeal 05/08/2016 at 01:340 Comments

UPDATE: 05/30/2016- I'll have to scrap the 18650 battery pack idea. The best way to build battery packs is to find a battery supplier in which you can customize packaging and chemistry of the cells. This is too specific for my DIY system and I'm getting lost in the details. Building a battery pack has taken more time and energy (get it?) than converting the motorcycle. I'm stepping back from the custom pack idea and designing the rest of the system to be more versatile and battery agnostic.


Choosing a battery system

Over at the elMoto.net forum, I contemplated battery options. CALB-style LiFeO4 prismatic batteries were all the rage 4 - 6 years ago but in the past 2 - 3 years it's been all about Nissan Leaf battery modules. HybridAutoCenter.com has a great article on these modules and they can be acquired relatively cheaply compared to other chemistry. While the Nissan Leaf module may be the bees knees in terms of cost, quantity, price per kWh it does rely directly on Nissan (and usually wrecked vehicles) as a supplier of these cells.

18650 Lithium Ion cells

18650 cells are usually 3.7v 2500mAh batteries that can be configured into series packs for more output voltage and parallel for a higher current rate. I have recently negotiated a deal for 1,650 cells from battery packs built by Tesla Motors. This is approximately 15,675 Wh of energy in 170lbs of cells. Compare this to the 5,760 Wh of energy I currently have using 174lbs of lead-acid batteries. Because the individual cells are self-contained and smaller it will be easier to build battery packs of different shapes to fit the curves of the motorcycle build

18650 "Bricks"

I envision standard modules of 3p16s cells arranged in "Bricks". Each brick is approximately a 12v 40Ah module with an integrated BMS, temp sensor, and etc. This will allow me to configure larger packs easily from smaller bricks. Once I get the EV Box DisplayBox integrated (speed, voltage, and amp functions for now) I will work on the details of the Brick architecture.---------- more ----------

Brainstorming

Description

Applications:

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.

Actual Tesla-built batteries

I purchased a set of 5 battery packs designed and built by Tesla Motors for an electric smart car. There are 330 2700mAh cells in each pack configured for 15S22P configuration. The gamble was that the cells are mounted in the packs loosely without any adhesive. After communicating with the vendor he tore open a pack and it looked clear and easy to disassemble.

Once the packs were in hand, however, the were securely epoxied in at the top and bottom of the casing. The case appeared to have a seam that could be parted, but the tops and bottoms of each cell was attached with a hard black epoxy to the outer casing. These cells are next to impossible to separate without damage. It's back to the drawing board.

Tesla Pack

UPDATE: 05/30/2016- I'll have to scrap the 18650 battery pack idea. The best way to build battery packs is to find a battery supplier in which you can customize packaging and chemistry. This is too specific for my DIY system and I'm getting lost in the details. Building a battery pack has taken more time and energy (get it?) than converting the motorcycle. I'm stepping back from the custom pack idea and designing the rest of the system to be more versatile and battery agnostic.
TODO: Rewrite and add more formal details of the battery packs.
TODO: Get the details of the vehicle they were removed from.
TODO: Decide to keep or scrap the modular features. Link Zero motorcycle webcast as reference. If scrap, spinoff modular idea in a separte log for future revision.
TODO: Link photos to the Google Photos album.
TODO: Edit uploaded photos with labels and arrows (and unicorns)
TODO: Add purpose (or objective) section as top header of page.

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