# My first conversion



## sokon (Sep 15, 2011)

Hello everybody

I am about to start my first conversion project . Here are the facts:

* country: switzerland
* team: Me (mathematician, so no usefull skills there ) with some help of an electrician and a physicist
* vehicle to convert: italjet formula 125 (sports scooter)
* aimed weight: less than 120kg
* aimed range: min [email protected] (3KWh?)
* aimed performance: top speed 120 kph, 0-50kph in less than 3s
* features: recuperation breaks

I was thinking to use a LiFePO4 accu system, since I heard it was saver to operate than LiPo`s and that it has a power/weight ratio that makes it usable for recuperation breakes without using supercaps to buffer the recuperated energy. As for the motor, I have no clue yet which system is the most suitable for the project, the power however, should probably be araond 12KW to accomplish the aimed performance.

Best,
sokon


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## RIPPERTON (Jan 26, 2010)

this motor might work in a scooter, air cooled AC
6:1 planetary reduction (nylon gears)










http://www.ebay.com.au/itm/170610906562?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649


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## sokon (Sep 15, 2011)

Dear Ripperton

thanks for your suggestion. Some questions remain:

* 600W seems rather low power for the aimed performance (< 1hp) the original motor of the scooter produces 10KW (from a 2 cyl. 2 stroke engine) and the aimed performance is a more or less the performance of the original motorisation.

* is this motor capable of recuperating energy by braking?

* it seems to me that 80% of effectiveness is rather low compared to other electric motors

Thanks for your help again and best regards,

sokon


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## KLX650E (Feb 25, 2011)

Heyy, no eine us de Schwiiz =D us welem Kanton bisch du?

have you already asked the STVA because of the immatriculation?? I'm waiting for an answer before I start, and hope that it comes soon. 

eventuallytis calculator could help you: EV-calculator

no guarantee that all the calculations are correct!!

will you keep the original transmission? (CVT?)


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## sokon (Sep 15, 2011)

hey^^

I live in zurich city 

I didnt ask stva yet, but I would be surprised if they made much trouble. From what I heard, the main issues with modifications made to vehicles are: noise, emissions and performance increase of more than 20%. All of which should not be a problem in my project . However, once you get your answer from the stva I would be very thankful if you could let me know the general statement.

Best,
sokon

edit: If possible, I will use a direct transmission, no gears and no CVT.


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## sokon (Sep 15, 2011)

would this battery/cell be something that fits my project?

http://www.ev-power.eu/index.php?p=...&sName=lfp1000ahc-wb-lyp1000ahc-(3.2v-1000ah)


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## RIPPERTON (Jan 26, 2010)

sokon said:


> would this battery/cell be something that fits my project?
> 
> http://www.ev-power.eu/index.php?p=productsMore&iProduct=308&sName=lfp1000ahc-wb-lyp1000ahc-%283.2v-1000ah%29



NO !
lol 1000Amp Hour
get Headway 8Ah

and its regen braking not recouperative breaking.
there is 750W version of this motor


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## sokon (Sep 15, 2011)

thanks for your advice

* why doesnt it makes sense to use just one big cell instead of many small ones? I see that this ends up in different voltage, but cant that be transormed: low voltage + high amperage --> desired amperage and voltage (of course leaving the power (almost) constant).

*according to google:
recuperative braking: 13'700'000 hits (when correcting my spelling )
regenerative braking: 895'000 hits 

*yes, but 600W or 750W or say 1KW doesnt change much? or am I completely wrong in comparing the hp of a conventional bike with the KW of an electric motor?

thanks for your help and valuable advice,

sokon


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## Yabert (Feb 7, 2010)

sokon said:


> yes, but 600W or 750W or say 1KW doesnt change much? or am I completely wrong in comparing the hp of a conventional bike with the KW of an electric motor?


No, you are right. Hp is hp (kw = kw) there are no difference they come from gaz engine or from electric motor.
12 Kw seem good for the porformance you need but more is always more fun!

You can see here a site who sell small DC and AC motor perfect for motorcycle.


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## sokon (Sep 15, 2011)

Hi Yabert,

thanks for the link.

will the battery system 

http://www.electricmotorsport.com/store/ems_ev_parts_batteries_lpf_gbs_kit48.php

be good for my project?

which engine would be more appropriate for the battery and my performance aim

http://www.electricmotorsport.com/store/ems_ev_parts_motors_pmac.php

or

http://www.electricmotorsport.com/store/ems_ev_parts_motors_pmac-ds.php

or is there something in between the two?

thanks and best regards,
sokon


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## KLX650E (Feb 25, 2011)

Recuperative braking is more used in german/ latin languages... 

You need to series the cells to get the needed voltage for your motor / controller you choose. You need to know how fast you want to go, this says how much kw you need. Then you need to know how fast you want to reach that speed, this results in the torque you need. 

When you know how far you want to go, then you can say how much Ah you need. To increase the Ahours you need to parallel the cells. 

I will post up if I get an answer from the STVA i think they want something that stops the Motor in an accident or something. 

Ps:I'm from lucerne hinterland


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## sokon (Sep 15, 2011)

ok some naive calculations yield:


diameter rear wheel = 489mm
distance per revolution = 1529mm
120kmh=33333 mm/s
revolutions per second of the wheel for the aimed top speed of 120km/h = 22
transition ratio (motor max [email protected]) = 3.8:1
torque at the wheel axle = 342NM
force generated by the wheel: 1398N
acceleration (120kg bike+80kg driver)=7 N/KG=7m/s^2
time from 0 to 50kmh(13.88m/s) = 1.98s

of course I am aware that this numbers are much to optimistic, but it makes me think that my aimed performance is achievable, in particular if I consider that range doesnt matter much (20km=12Mi will do). 

@KLX650E: I found a blog (http://mein-elektroauto.blogspot.com/search?updated-max=2011-02-24T21:06:00+01:00&max-results=3) of a guy who was talking to somebody in the stva about electric conversions, he says:



Es gelten dieselben Zulassungsbedingungen wie bei der ersten Inbetriebsetzung des Fahrzeuges.
Das Chassis darf nicht abgeändert werden.
Die Motorenleistung darf nicht mehr als 20% über der ursprünglichen Leistung liegen.
In Bezug auf Abgas und Lärm existieren keine Vorschriften.
Im Bereich der elektrischen Installationen muss nichts Besonderes beachtet werden.
Das Gesamtgewicht darf nicht überschritten werden. Gesamtgewicht bezeichnet das höchste Betriebsgewicht mit welchem das Fahrzeug verkehren darf.


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## sokon (Sep 15, 2011)

hi folks 

some decisions have been made and some are to be made soon (I hope for some advice there).

*motor will be
http://www.electricmotorsport.com/store/ems_ev_parts_motors_pmac-ds.php

*still open is the energy storage system, only thing that has been fixed there, is that the battery chemistry should be lifepo4 (or something that is comparable in terms of safety and energy denity and power density). I was considering to get an out of the box lifebatt system with bms etc integrated. However, lifebatt hasnt answered to my request so far. Any suggestions are welcome! Requirements of the battery system (including all: battery,bms,casing,wiring...) are

energy: 2 to 3 kwh
power: 6-8 kw cont. >15 kw for 20sec. 
amperage and voltage: so to fit the motor
weight: <30 kg
price: 2500$
chem.: lifepo or equivalent (in particular: no lead acid, no nimh, no lipo) 


the budget looks as follows:

Total: 5000$
Donor vehicle(2nd hand italjet formula 125 scooter): <500$ 
motor and controller: 1500$ 
energy storage: <2500$
rest: 500$

Thanks for your help and best regards,
sokon

Edit: the transmission should be gearless and clutchless.


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