# 12v Series hybrid scooter from scratch, need help.



## One Equals Two (Feb 25, 2010)

Okay, to the point:

I want to spend as little money as possible. 

I want it to go about 45 - 50 mph.

I want near "unlimited" range. Actually, 60-70 miles a day is fine.

I want it to be fairly reliable.

(Explanation why. I have little money to spend, so, obviously keeping the cost down would be ideal. I used to have a scooter that was a 2 stroker. It had 2.5 hp and would constantly make it to 30 mph. However, that was just too slow. Also, it required multiple fillups per day (commuting to school and back), and it constantly broke down. I had to disassemble it on the road several times in the month I used it. So I carried a tool pack with me as well, and a 1/2 gallons of gas, etc etc. In short, it wasn't convienient at all, despite the 100 mpg. The little 2 stroke was grossly over worked and super noisy as well. So, i sold it in favor of the much more expensive car I now drive.)

Anyway, I have an idea that of throwing together a hybrid scooter running on 12v. Why? I see it like this. 12v car battery (I know, not the best for evs), but cheap (I already have 2) and has good "power". Motor, starter motor from my old Neon. Free, and has a peak power of about 5-7 hp (560 amps at 12 v) . And then a motor from my old mower or weedwacker hooked to an alternator from my old Ford (also free). This would charge the battery when topped off and would be a lot easier on the ICE because of no varying loads. Also, if needed, I could run on ev mode only in case of engine failure, which happened to me all too often before. And, on short errands, ev only would work just fine (obviously, I am saying nothing new) The only thing I don't know much about are 12v controllers, or controllers in general. I know spacw will be an issue, but with an old blown gas engine scooter frame, it's doable. Anyway, I lean towards 12v stuff because I have most of it already, and because I could have an alternator charge the battery because it's natively 12-14v, not 24 or 36. And the starter, same thing. Anyway, II figure if the entire system is 12v, then I wont lose much to inverters and chargers, etc, boosting "mileage" etc. I may be thinking too simplistically here, but it seems to make sense to me as of now. But that's why I am asking.. 


Has anyone tried a 12v scooter before? Or a 12v ev in general? I am most likely overlooking something, but as of now it seems feisable. Please feel free to point out errors in the logic, etc. If this works out well,bI just may try a car series hybrid later as well.


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## Woodsmith (Jun 5, 2008)

Ummm, where to begin.

Forget the starter motor. It doesn't have proper bearings in it and is not designed for continuous running. If you try it will overheat the motor and also burn up the bushings. It is also heavy for its output.

Forget the car battery. The plates will be knackered after a couple of runs. At least use Optima batteries or other deep cycle types.

Forget the weed whacker as a generator, it will burn more gas then if you just powered the scooter on an ICE. This is just down to losses in each conversion of energy through out the whole drive train.

Forget the alternator, they are really inefficent as they are designed to use the massive amount of spare capacity of ICE power in a car to generate a measly little output.

You would be better off getting a decent motor, controller and a set of batteries and making it completely electric IMO.


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## One Equals Two (Feb 25, 2010)

I know a full electric scooter would be ideal, but if I manage the run it out, I am dead in the water. I don't want something like that (I need to be punctual). So that's where the hybrid thing comes in. I see a few gas generators that run on .7 gal of gas for 8 hr at half load. Granted, that's at 500w output, but even at that, I can't see how the weed wacker would be worse. Same 4 stroke engine. Anyway, and the alternator seems to be a 60-70% efficient generator, so yes, although not amazingly efficient, it's no different than if I hooked up a stand alone generator to charrge the battery. 

I understand the need for a different motor though. I have some questions about hub motors. I see some 1000w ones for not too much, so I wonder, if I get 2, would I only figuratively double my acceleration, or would top speed change too? 

I understand the need for a new abttery too. Pretty much I wanted to see if I could throw this thing together for next to free and get away with it..... I had other questions but have already forgotten...


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## Woodsmith (Jun 5, 2008)

Oh you can certainly 'throw something together', that is fine.

What is your college commute like? How far, what sort of terrain?

It may be possible to have enough battery to make it all the way and maybe back again if you can't charge up while there.

The efficiency loss with the weed whacker is from using it to generate electricity and then using that to run a motor. You have two additional loses in the train that you wouldn't have if you just used the weed whacker to drive the scooter.
Granted that you will also have energy in the battery as well but you will have diminishing returns due to the weight of the ICE, fuel and alternator on the battery and motor and vice versa.

If the one 12v system gave you any usable range at all then most of that will be eaten up by carrying the ICE and stuff around until you need it.
Then you will be runing the ICE to charge the battery before you can move off again. Otherwise you will be trying to run the motor and charge the battery on the alternator at the same time which will have a massive effect on fuel consumption.

Lets see is all electric is even feasible and then look at the alternatives and cost saving.


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## camerondmm (Apr 28, 2009)

Checkout the "LongRanger" on this page: http://www.atomiczombie.com/main.aspx?click=plans (it is the second to last one).

Gives you an idea of what it takes to do ~100km on an electric 2 wheeler. But keep in mind, it is a lot lighter than any scooter.


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## One Equals Two (Feb 25, 2010)

My commute is about 20 mi one way, but I rarely go just to school and back. I go shopping occasionally, to my friend's, etc. It's vey hilly for a few miles or so too. I wanted a scooter so it could be legal to go fast on the streets. I got pulled over on my goped and was fined $700 for no insurance once, and so far I haven't been able to convince the state to drop the charges because they want money from me. Also, electric bikes are also illegal here with no insurance, so, seriously, I need a registerable vehicle. I like the idea of a mountian bike honestly, but for some reason, bikers here get stuff thrown at them all the time and people with big diesels like to blow smoke in our face (pull up next to us and let off on the gas). It very annoying honestly. The scooter or motorbike would at least be quick enough to not let a bunch of cars go by to taunt me...

Anyway, I've thought about electric motorbikes, but then it looks like a whole different area of cost. I can save up for some nice ev parts, but I had wanted to make the hybrid with mthe stuff I had in front of me. I guess it's not going to be much of a useful vehcle right now, so anyway, I guess I am already looking at an electric something else. 

All electric is okay for in town, but I often go on long trips (300 miles) so a hybrid will still be ideal for me. I like that idea because then I can run all electric for school, and hybrid for road trips. But I can use my Taurus for that though since I get 33-36 mpg freeway. It really just boils down to which is most cost effective for me. Haha sorry, I am kind of going around in circles right now. Thanks for the tips and info guys, it's helping. 

And, one more question. High amps on a 12v system is a lot more inefficient than a 24v system with have the amps right? Just checking myself.


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## Woodsmith (Jun 5, 2008)

Haha! I went round and round in circles trying to pin down what I really needed at the begining.

I settled on keeping the diesel car for everything that an EV couldn't do.

It would be worth your while looking at the types of all electric motorbikes and scooters out there. 
Commercially there is the Mavizen and the Vectrix.
There are also a lot of DIY versions to compare.

Looking at the types of bike others have converted will help you determine what you can build that will do what you need. make the right sort of bike and you can tow a small trialer with it. That could be your generator for those longer journeys.

A bit of basic theory:

Power (P) is measured in Watts (W).
Electrical potential is measured in Volts (V).
Current (I) is measured in Amps(A).
Resistance (R) is measured in Ohms.

Watts = Volts x Amps. More volts less amps.

Volts = Amps x Ohms.

Watts = Amps x Amps x Ohms. So more amps equals more heat genrated in the motor as a loss.

Although high voltage and low amps can give you the same power as high amps and low voltage due to the resistance of the motor windings as the amps increase the heat in the windings increase lots.
Using a high voltage to keep the amps low means that you can have the same power but with much less losses in heat so the motor is more efficient.

If you want to be able to make your commute you would have a set amount of power that you need and a set amount of energy in your batteries.
If you had a high voltage then you will waste less energy heating up the motor windings and so have more energy available for your range.


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## camerondmm (Apr 28, 2009)

I hate to say it, but if you want a registrable vehicle, it will probably be impossible to beat a nice scooter. Someone at my work commutes on a Honda Jazz, and it is a very nice machine. I think she gets it serviced about once a year. Looks good and goes pretty fast (maybe 80km/h, can't remember).

This doesn't mean you can't have a nice EV scooter that does the same... Just that it'll cost more.

By the way, I know those kinds of drivers!


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## One Equals Two (Feb 25, 2010)

Hey Woodsmith, if you could send me over a diesel Peugeot or Renault, I'd be forever grateful!! Here in the "good ole US of A" we don't get things like fuel efficient cars. Sure we may think we do, but it's all rubbish. I've had a Geo and a VW diesel, and they were both junk. My Civic 1.3 was reliable, but 0-60 was 27.6 sec with 3 passengers...

I had a Yamaha 50 scooter for a while, and it was quite awesome I have to admit. I had multiple carb issues, but it still got around 140 mpg (after I tuned it). But, it was sluggish on the low end, and would "only" top 55 mph. But that was literally a 2 minute journey to get there, so most of the time it was 40-45 mph before I was plateauing. I was looking for something with low end grunt and some happy high speed, but it's really just looking like everything else is cheaper. If my state wasn't such a jacked up one, I'm sure I'd be much happier with an electric bicycle, but that's much of an option for me. 

I think what I'll have to do is map out an ev project, and then just save for it. I am all for having an ev, or hybrid, but it looks like it's going to not be cheap.

I've always wanted a cruiser bike, so I think I'll start saving some pennies for it and then go from there..... It all boils down to money doesn't it?


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## Woodsmith (Jun 5, 2008)

Yeah, it is either money or time one has to wait on.

My biggest concern with my build is not knowing if I can afford the batteries when I am done with everything else.

My diesel Skoda Octavia gets me 60+mpg. Usually I am on 62mpg on my commute and have managed 84mpg once.

Best thing is to start by determining your ideal requirements for an EV and then your essential requirements and seeing where, in between, you can get the best compromise.

Once you have the plan established for what you can have you can then start sourcing/scrounging for it. Unless your plan changes drastically you should be able to gather parts over time while saving for the costly 'must buy new' parts.


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