Noob Attempts EV Conversion: reVOLT

saha6818

1 mW
Joined
May 20, 2017
Messages
10
Location
Seattle, WA, USA
I fixed up my girlfriend/fiance's 1973 CB350F that had sat outside for 17 years. It's nearly original and pretty fun to ride - all-out racing around without necessarily breaking the speed limit. But we both got tired of me constantly having to tinker with the carbs because she doesn't ride much (plus I'm apparently not great with carbs). Also, the engine is showing signs that it might be near the end of its life. So she bought a new Ninja 300 ABS and loves it. Meanwhile, I've begun a commute that is 18 miles and one hour each way. It's a mix of road types and briefly requires a top speed of at least 65mph. I currently split the commute between a Daytona 600 and a WR250R. The WR gets great mileage, is comfortable, and will go anywhere. The Daytona is fast, fun, and good at lane splitting (which is illegal here, so, ahem, I don't do?).

But all that carb tinkering, sucking on/siphoning gasoline hoses, and general knowledge of ICEs has me, as a minimalist, longing for a simpler commuting machine. Fewer moving parts. Fewer fart sounds. Less pollution. Also, the CB has a history with national parks, so it'd be cool to continue its story. It was a finely tuned, powerful machine when new. Let's get it back that way. So, the conversion I've long dreamt about is finally starting. I want to call it reVOLT.

Requirements:
1. Top speed of at least 65mph
2. Usable range above 40 miles
3. Fun
4. Target price: sub-$4500 USD (CB350F not included)
5. Slightly sportier ergonomics than stock
6. Doesn't look like a high school science project. Maybe even maintains some retro-awesome style. Identifiable as a CB.
7. Reliable (as reliable as the other bikes would be great)

Plans so far:
* I've got some specific info from Enertrac that sounds good. Includes liquid-cooled motor, controller, DC-DC converters, throttle, etc. A hub motor would be quieter than a chain drive, less finicky, and save space in the frame for batteries and electronics.
* I was thinking of using two used Tesla Smart ForTwo battery packs, but now I'm thinking of building my own custom pack using new 18650 cells. On back-of-napkin calculations, I'll need about 830 of them. The math is subject to change when I do it right.

What I need from you:
Shout if you think these plans are more flawed than I know!
 
Have you looked at QSmotors? Some people are using their motors with success. Maybe just another option to compare with.

Building batteries is a lot of work but should give you the flexibility you'll need to try and keep the styling organized.
 
Go for a QS hub motor if you can. They are reliable, cheap and powerful, so it's basically a no brainer here. IMO, hub motors are the way to go, they don't use space, they have plenty of torque and they are quite efficient. Unless you plan to use some kind of gearbox, there is no point using an inboard motor.

For the battery, your plans seems ok. If I were you I would purchase a ready to be used pack or tailor made from a decent expert, since building your own is quite difficult, the time you'll spend on it, plus the probability of screwing up, giving up, doesn't worth to make the effort (in my opinion). Especially if this is the first time you're building a lithium pack, you probably shouldn't directly tackle high power applications, any screw up can potentially be dangerous and costly.

About the controller, it will mainly depend on what you plan to use as final battery capacity, voltage and C rating, plus the weight of your machine, your own weight, wheel size and motor characteristic. In my opinion, decide first of what battery you'll use/you can afford, and then it will make the other choices more obvious.

The positive point is that this chassis seems to be lightweight, with potentially enough space to put a good battery. You can expect great performances with this, 70 mph shouldn't be an issue at all, with very good accelerations.
You can have a parallelogram shaped battery up front and put the controller in the triangular shaped space in the middle. Could look good if you do the job properly.

Again, start by defining your battery: contact suppliers and define your maximum cost for this element, then see what is available. If you have doubts about different batteries offers from different suppliers, we can help you decide :)
In my opinion, you should go for at least 72V, ideally 100 or more, with a minimum capacity of 50Ah, the more the merrier. I have no idea how much this could cost in the USA, here in China I guess it would be around 8000 - 10 000 yuan or so for a 100V 50Ah LiFe.

Good luck in your project, the most difficult part is to actually make the first step and start it!
 
Thanks for the info, folks. This being a noob thread, I'll introduce some noob questions. The Enertrac motor I'm looking at has a claimed 30KW peak. I'm not seeing motors that powerful in the QS selection, though they certainly look large enough. And I'm not seeing motorcycle ("escooter") hub motors with liquid cooling, which I'm thinking is a good idea. Do you have a model in mind? Also, is the selling point the price? I'll Google around too, but your impressions about QS reliability will be nice. Lastly, one selling point on the Enertrac is that they've recommended 12v converters, controller, throttle, etc. But I'm sensing that the community here would have ideas of which of those would be good fits. My worry is that I'll buy some wrong components resulting in wasted time and money. A sort-of kit is attractive.

Thanks!

As I was sitting in traffic on my hot bike today, I was fantasizing about shooting home on a clean, quiet, little 1973/2017 motorcycle.
 
They were an awesome little machine, so electrifying it would be a great lease on life.

Lots of options for small-medium power motors, and controllers too. Just make sure when you order them you let them know what motor or controller you would like to pair it up to. Efficiency difference can start to matter if they haven't been optimised.

Hubs are great for a clean looking build with minimum cosmetic effort.

Keep us posted!

Chris
 
Go for hub motors. Enertrac are nice, too (I scored one used), but QS have winds that require less voltage (another mistake I made, but well...).
QS only rate continuous power, the MHM 602 has 10/30 in the single variant. Check https://endless-sphere.com/w/index.php/Electric_Motor_Selection for some options.

I'd say speak to Mark in Enertrac and PM Vito from QS (see https://endless-sphere.com/forums/viewtopic.php?f=31&t=65972) to see what they might recommend.
BTW, if you buy a new controller, go sinewave... :p
 
Okay, I'm 90% sure about buying Enertrac. I'd like to feed it a little over 100V, so I'm thinking of buying one of the 1000-cell packs from ebay (link and description below). I've been hearing about these from jehugarcia's YouTube channel, and I'm somewhat confident about their quality. So here's today's stupid question. Let's make it three. I took a few college physics classes but have forgotten most of it. (1) Can I put 48 of these packs (10s2p w/18650 cells for 36v and 4.4AH) into a 3s16p configuration and get 108V and at least 300A? (2) The current part has me confused (I'm still working on the current and range math in a different window). Is the last battery in a series of batteries okay with having a whole lot of electrons coming through? Is there a limit to the number of cells I can put in series before BLAMMO? For what it's worth, each pack is supposedly rated for 10A continuous. Finally, (3) I know nothing about battery-management. Is the built-in BMS in these packs any use to me? Any chance I could just plug the entire bank into the correct voltage charger and have everything charge evenly?

Thank you for your patience and input! In the midst of wedding prep, the CB has become a storage space. I must save it from that fate! (But it's mostly surrounded by beer, so that's nice.)

http://www.ebay.com/itm/201920561877?rmvSB=true

50 LG 36V 4.4AH BATTERY PACK 18650 EBIKE POWERWALL BATTERIES 1000 CELLS W/ BMS
YOU CAN'T BEAT THIS DEAL!!! 36V - 220AH - 7.9KW - 7920W

Item specifics
Condition:
New: A brand-new, unused, unopened, undamaged item in its original packaging (where packaging is ... Read more
Brand: LG
Voltage: 36 (42 MAX)
Battery Size: 18650
Model: LGEAMF11865
Amp Hours: 4.4 (2200 PER CELL)
MPN: LGEAMF11865
Chemical Composition: Li-Ion

...HERE ARE 50 POWERFUL 36V 4.4AH BATTERY PACKS MADE OF 20 BRAND NEW AND GENUINE LG 18650 BATTERIES FOR A TOTAL OF 1000 18650 CELLS. I KNOW ALL YOU "DO-IT-YOURSELF" E-BIKE AND POWERWALL BUILDERS OUT THERE ARE LOOKING FOR AFFORDABLE AND HIGH QUALITY 18650 CELLS. THIS IS PERFECT FOR YOU. GENUINE LG 2200MAH (MORE LIKE 2270MAH - 2310MAH) BATTERIES. HIGH DRAIN MEANING THESE ARE RATED FOR 10A CONTINUOUS AND 20A MAX PER CELL. SO THESE ARE MEANT TO HANDLE THE EXTRA POWER. DO YOUR RESEARCH AND REALIZE YOU ARE GETTING 1000 BRAND NEW LG 18650 CELLS FOR THIS PRICE. ALREADY SPOT WELDED AT 10S 2P WITH A SOLID BMS. I SEE YOU E-BIKE BUILDERS PAYING $190 FOR A 36V 10AH BATTERY. YOU CAN BUILD THAT WITH THESE FOR HALF THE PRICE. YOU JUST NEED A NEW CONNECTOR AND TO CONNECT THE 2 LEAD WIRES IN PARALLEL TO INCREASE THE CAPACITY. ...

MOST OF THESE WILL HAVE A SIDE MOUNT BMS WHICH IS EASIER TO DISASSEMBLE AND MUCH EASIER TO WORK WITH FOR THE DIY COMMUNITY. ALL NEW, UNUSED BATTERIES, SAME CAPACITY, SAME BRAND... YOU CAN'T BEAT THIS DEAL. GET EM WHILE THEY LAST!

NO SHRINK WRAP TO SHOW THAT THESE ARE NOT KNOCK-OFF BATTERIES. THIS IS THE BEST OF THE BEST AND THERE IS NOTHING TO HIDE! YOU CAN USE THIS AS-IS FOR YOUR HOVER BALANCE BOARD AS IT HOOKS RIGHT UP.

...

THESE IS NO SHRINK WRAP ON THESE. OTHER BATTERY PACK BUILDERS COVER UP THEIR USED OR KNOCKOFF BATTERIES WITH POORLY CONSTRUCTED PACKS. THIS IS DONE RIGHT WITH THE RIGHT BATTERIES! COMES WITH THE XT60 CONNECTOR, RSFR-H TUBING AROUND THE WIRE LEADS, AND THE BMS! YOU CAN ALWAYS ADD A NEW CONNECTOR IF YOU WANT TO USE THE PACK THE WAY IT IS TO FIT YOUR APPLICATION.

CHECK MY FEEDBACK AND BUY WITH CONFIDENCE. I AM A GENUINE SELLER AND I SHIP EVERY DAY. WE ARE A FAMILY OWNED AND OPERATED BUSINESS LOOKING TO DRIVE DOWN THE LITHIUM ION BATTERY COSTS FOR EVERYONE!
 
Thinking about this again, I'm thinking that the wiring that comes with the packs couldn't support putting three packs in series, and I suppose that'd be a problem for the little BMS in each too. If you agree, then I'd need to custom build these packs anyway. I'd be willing to do that given the price unless I hear serious concerns about the quality of the cells.
 
Just as an FYI - I run an Enertrac 602 laced to a 17 inch Warp Racing Rim, my pack voltage is 108v Fresh off the charger - I can just about get 65mph max at an indicated 97v.

Super torquey between 20 - 50mph though :)

Cheers,

Mike.
 
Thanks for the info, Mike. I'm jealous. Is your motor liquid-cooled? Do slight hills or headwinds lower your top speed a lot? Have you used the motor enough to comment on reliability? Thanks again!
 
Hi - Yes - I have the liquid cooled...... I had a bearing fail on the motor on my first 40 mile run out - straight after the MOT test! Not Enertracs fault - just a bad bearing, no grease at all in it. I Got the OK from Mark at Enertrac to do the replacement of the bearings myself (not that hard really).

The motor is so Torquey that headwinds / hills don't really seem to make much difference - I have a limit set at 300 amps so the motor is never exceeding 30Kw. At 65mph I'm pulling about 115amps on the flat, but my bike is a little heavy...

My Kelly controller blew up on my 4th trip out - They have sent me a new one under warranty which I'm fitting this weekend. Kelly said the controller was so badly burned out that they could not tell what had caused it. I was only pulling about 25 amps when it went up in smoke.
The only thing I will be doing differently when the new one goes in is to have a dedicated DC/DC just for the 12v for the controller and contactor. All other 12v electrics will be fed from a separate DC/DC.

I'm sure you will really like the motor :)

Cheers,
Mike.
 
More planning progress. Closer to abandoning the effort :(

I dig these batteries - 13 of them in series:
2013-15 62Ah Nissan Leaf Battery Module 2x3.8V cells, 470Wh
http://evbatterycenter.com/HAC4/index.php?option=com_hikashop&ctrl=product&task=show&cid=84&name=2013-nissan-leaf-battery-module&Itemid=605

Unfortunately, a dude can't just plug in a BMS for this setup. So this from them: Project like this is are custom. Search for Elcon charger - they can be programmed tto the exact voltage at the order. example: https://evsource.com/collections/elcon

A custom BMS sounds like a valid option. I've written a fair amount of good code and wired up a fair number of things that didn't then blow up. But given the dangers of exploding myself out of a traffic jam, I better not bite off more than I can chew. Maybe ElCon's "consulting services" are for me? Maybe I should try bribing my local EV group with beer (they seemed friendly at a local car show). Maybe I should give up and wait a few more years until there are plug-and-play solutions?
 
Nice project

Would make a nice Cafe racer.

I would keep your frame mounts simple this way you can change battery packs and design. Do you intend to ride in cooler temps the Nissan Leaf pack hate the COLD suffer big voltage sag.

Controllers are going to be a problem at 30 kw you really need something bullet proof, also run as high a voltage as you can less amps and smaller wire.

Good luck.

Cheers Kiwi
 
Inwo, I think 24s might work. The photo shows 80.91v. Is that fully charged?

Kiwi, I think it'll probably end up as a sort of cafe racer. The last custom bike I built was a cafe/rat/brat. https://www.youtube.com/watch?v=DdyZdPIuwEQ

My commute rarely gets below 35 degrees F. If the bike gets too slow, I could maybe just rotate in a dinosaur-juice bike for a few days.
 
It's not mine. From a customer who bought a bms-24.
But, no, I charge my 24s volts to 100v.
 
Inwo, I read your thread and appreciate your work. I can understand from the photos how the BMS is hooked up. Could a noob like me just copy the setup and expect things to work even without understanding 100% of the lingo (for customizing the settings, etc.)? I know this is a noob question, but mind the title: Can I just then hook up a 100v charger across the pack and consider the bike's power supply done?
 
I know of some who ran a 20s Leaf for over a year without bms or balancing.
I wouldn't do it. At minimum connect a monitor to the pack. Use a Bluetooth bms for not much money.
The bms-24 works fine set to defaults. Connect the wires as in picture and good to go. Plus as you learn settings can be fine tuned.
For example, to balance pack, only need to set to "on" in the menu.
I'm going to update the for sale thread.
 
The BMS makes sense to me now. As far as the charger goes, I just order a charger, tell them to set it to 100v, and connect it across the pack? I'm thinking about choosing Elcon. Given that, I think I can do the math and decide if the build is worth the overall cost (I'm guessing $4,500-5,500).
 
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