Motorcycle build questions

Hello all,

I am in the process of building an electric motorcycle out of a 1988 kawasaki ninja zx600-c. This is one heavy street bike!

On craigslist I found a OSMC that I was thinking of using. It says its only for brushed dc motors, but I've also heard that brushless dc motors work as well.

The website is basically defunkt now, but the controllers state they can handle up to 50v 160 amps continous with 400a surge.

If I had a motor set up at 48v that had a lower continuous amperage consumption, would I be able to get it to work? If anyone can steer me in the direction to program this with an arduino it would be much appreciated!


As for motors, I am finding it a hard time to choose one, I've narrowed down my results but I'm not sure if they will fit my needs, can someone verify? Can I find the kw rating from horsepeower if I take into account that 1 hp=745 watts?


http://www.cloudelectric.com/Motor-ME0709-MotEnergy-p/mo-me0709.htm (Does 125 amps continous and 300A surge; 8hp/6kw at 48v; also able to go up to 72v in future is a plus. Should I just find a 72v controller for this build then? Any suggestions?)

http://www.cloudelectric.com/product-p/mo-me1007.htm (weighs less and has around 5kw, only 48v)



http://www.cloudelectric.com/product-p/mo-me0909.htm (both of these weigh in the low 20s, 5kw continous and 15 kw for 30 seconds)
http://www.cloudelectric.com/product-p/mo-me4201.htm (unsure about specs)



Any insight or suggestions would greatly help me out. Thanks!

4dollarjoe said:

...This is one heavy street bike!...

Click to expand...

I converted a heavy moto as my first build, and Pig-E-Moto was a huge mistake. All of my ebikes since have had drastically more performance. That included the ultra-cheapie e-scooter that I upgraded from 15kph of lead worthlessness on 2 wheels, to a 50kph scooter capable of climbing mountains with my daughter aboard.

With the sub 10kw power you're talking about you should be looking for a lightweight moped as the donor bike. AFAIC if an emoto can't exceed the performance of a 50-80cc gasser, then it shouldn't be built, because it gives the wrong impression about electrics.

Wow, those are some good prices... I'm very tempted to order one... (What is Cloud Electric's reputation around here?)

I'm no expert on these larger motors, and just recently started to think about building a system for the Suzuki 800 rolling chassis I acquired a month or so ago.

But if it were me, I'd be most seriously looking at the 4201 motor,

(Better info for them is here: http://kellycontroller.com/mars-4201etek-comparable-pmsmbldc-motor-p-736.html)
and
a Kelly KBL72301X controller... Kelly actually recommends the KBL72401E, but unless you really want to push it, I think the 301 will do, and save a hundred bucks.
Or maybe a KEB 72601 or KEB72800 or KEB72100 would work better.

Have to think about this more..
Thanks for finding the sale at Cloud.

Ideally I'm going to shave down the motorcycle to look like this to save weight. The majority of the heavy weight is from the heavy motor, which once removed should make the motorcycle adequately light enough.


Thanks for the more info on the mars 4201, but is there any ratings on horsepower? I can't find any.

SO ideally for this bike I'd like for it to have a nice range of around 30 miles. I'm either going to got for a 48 or 72 v system with fast acceleration in mind. There are some decent hills around my area so I'd like the power to overcome some slopes.

Any suggestions for batteries would be good too.

4dollarjoe said:

Thanks for the more info on the mars 4201, but is there any ratings on horsepower? I can't find any.

Click to expand...

Sorry, I had so many windows open, I got confused.
I can't find the specs for that motor yet.
Maybe the ME0709 would be a better choice..

Was trying to stay with 72 V operation and brushless, and somewhere in the back of my mind I thought the 4201 would do ~19 HP continuous, and 36HP peak for a few minutes, but it is about half to 2/3 of that, just going by volts*amps=watts /800

At least by going brushed, you can save money on controllers.
Like I said, I'm new to these higher power builds, and pretty rusty on the lower power stuff too.
(Just got back in the e-v game after 6 years of doing other stuff, and a lot has changed)

No problemo, decided to pull the trigger on the me0709 after talking to the guy, should be able to fit my needs. Once I get it I'm going to see if I can test the osmc on craigslist to see if it works. Otherwise I guess I'm off to wait on ebay :/

Hey guys so the controller specifications says it can handle 50v, but only 36v of batteries. I do not see why I cannot put 48v of batteries though.

As my battery choice I think I am going with these:

http://www.pepboys.com/product/details/838838/00469/?isPayInStoreOnlyStore=false


If I run 36v I should get near my range, and it should still out preform a briggs and stratton at 48v. 4 batteries should be awesome and it will only cost $700 after coupon. These are agm batteries that are resilient and pretty good. They also have excellent reviews and have 4 year warrenty.


If I can indeed run at 48v Ill do 8.5 hp continuous and be able to go 48 miles on a single charge. The bike also will still weigh less than 300lbs when its alteast in the 500s right now with the combustion motor.


Does anyone else have suggestions for batteries?

I think your math might need some help here. The RC on those batteries is 160. that means it can go 160 minutes discharging 25 amps, which in normal terms means it has a capacity of 67 Amp hours. That will not power your bike at 8.5 hp for an hour, more like 30 minutes if it was actually capable of that. But Lead acid based batteries like AMG suffer from Peukert effect, meanin as the load increases, the capacity goes down. Trying to pull 100 amps from that battery, the capacity will be much much less, perhaps only 30AH.

But that's all unimportant, as it's a starter battery, not a deep cycle battery, and will be dead in a couple rides if you try to use it for continuous power. You should take a look at Lithium batteries. Massive weight savings, massive size savings, and since the bike will be so very much lighter, you don't have to overbuild everything, , and you would need much less power for the same performance. the cost would go down because of it, and the battery might be more, the total cost of the bike could easily be less.

The motors you picked would work great for a moped. They might be ok on something up to a Honda CR100. The power levels you want are better in line with a small motorbike or a good moped. Many of us run bicycles with more power, but it is a good range for a light weight motorbike.

The controller says 36 volts because a fully charged 12 volt battery will be higher than 12 volts. Depending on the type of chemistry, a 48 volt battery can have 52 to 58 volts hot off the charger. Far more than the max 50 volts of the controller.

Okay thanks for the insight. I think I might as well go big or go home.`If I go for a set of 72v lithium ions and get a real controller purchased, what would be my best/cost effective options.

Everytime I go searching for lithium batteries I end up browsing alibaba pointlessly. Can someone show me a good setup that I can buy. Having 30hp at 72v would be phenominal.

Okay lithiums are looking to be way too dangerous and expensive for me to handle.

I'm settling for some UB12500 s because if I run them at 72v I'll have around 40 miles range with 12hp continuous and 30hp max. Weight of the entire battery system will be around 200lbs but that is only a fraction of what the bike weighs. If I wanted to decrease the batteries I could do 48v at 140lbs too with 8hp continuous and 20hp max. Batteries will only cost $600 too.

http://www.batterystuff.com/batteries/mobility-scooter-wheelchair/UB12500-45977.html


As for a controller, the osmc isn't worth the trouble. I think I'll settle for a kelly kdz7230024v. It will work right? Since my motor is brush pm. Outputs the exact continuous amps I need too.

http://kellycontroller.com/kdz7230024v-72v300aseriespm-p-961.html

The controller will work.

The batteries will disappoint you.

http://kellycontroller.com/kds72200e200a24v-72v-mini-brushed-controller-p-762.html

Debating on going for this controller, since it is smaller, lighter, cheaper, and still 120a continuous. I'm not sure if the hit down to 200amps for 1 minute is worth it though.

The kelly website says for 'optimum' controllers, you should choose one that has twice the power you need. Is this true or will I have the same performance with 200a continous controller or a 120a continuous controller on a motor that only does 120a continuous anyways?

One thing to keep in mind is that if you decide to build for a lower voltage now, and then up it later, you're going ot have to regear the bike for that--the motor will spin faster at the higher voltage, for hte same throttle setting on the same controller and same load.

So if you start at say, 36V, and then go to 72V, you'll have to change the gear ratio to the rear wheel by a factor of 2 to get the same top speed (and throttle behavior).

The good news is that doing that will also increase the torque you get at startup....

RLT said:

The controller will work.

The batteries will disappoint you.

Click to expand...

http://www.extremetech.com/computing/186952-stanford-creates-holy-grail-lithium-battery-could-triple-smartphone-and-ev-battery-life

http://www.industryleadersmagazine.com/lithium-battery-that-could-last-for-days-may-be-coming-soon/


Gonna wait for these to come out before I convert it to lithium. At that point I could probably throw in a second motor!

The bike is going to weigh less anyways so I don't mind. Worse thing that happens is I repurpose the batteries to another project. Some people have gotten them to last 8 years too!

My guess is it will be years, at least, before you see any newly developed tech actually get to manufacturing. Some of it never gets there because the practical problems of making realworld cells are too costly to overcome to make a cost-effective product (or because the owners of the patents diddle around and nobody gets to try).

beware that Kelly brushed controllers limit amps on start up. So if you have a heavy bike, you will want a higher amp controller. I have a 100a and 600a. On 100a limit, a 300lb scooter has almost no take off torque at 66v. Start on a hill? Forget it