# Planning my first build



## nxp (Apr 6, 2011)

I'm thinking of building my first EV - and I prefer motorbikes over cars. I can handle mechanical and electrical stuff quite ok, but I'd like to see opinions of the feasibility of my build (before I spend money).

I was thinking of using:
>a Mars ME0709 motor
>a homebrew controller (hoping to implement regen too)
>headway 16Ah cylindrical cells, 24s (1.2kWh)
>charging using standard "industrial" power supplies, with the homebrew controller terminating the charge
>a small 125cc donor bike with a new "subframe" bolted instead of the ICE (on this bike the engine is part of the chassis) - both the battery pack and the motor would be mounted in this subframe

I'm aiming for a curb weight of 150kg or less. (and I'm a pretty light rider). 

What kind of range could I expect with this setup if I ride conservatively (under 100km/hr)? Most of my commute is city with the rest being country roads, and totally no highway. Would I have to go for 24s2p to get a 40km range?

Does anybody here know reasonable priced suppliers for headway cells in the EU? I am thinking that the battery pack will probably be my biggest expense but I'm definitely not going for lead - it will be too heavy.

Are there any other good priced cells that I might use? From what I've been reading Thundersky and CALB prismatics are probably too big for what I need.

What is the typical brush life for a Mars "etek replacement" motor? Would I end up replacing brushes every 2000km?

Please butcher my ideas and tell me where I need to get more realistic.


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## Yabert (Feb 7, 2010)

Welcome

You can see here a relatively comparable build: http://www.diyelectriccar.com/forum...-sm-2005-electric-48239.html?highlight=suzuki

My DRZ weighted 152 kg, use headway cells, has a top speed of 110 km/h and a range of 30-40 km.

So, your setup seem correct (except battery) if you have in mind than it's a low power setup (less than 18 peak hp). But if you know that, I agree, 10-15 hp is more than enough for lightweight motorcycle at city speed.

About cells now! I has a 2.5 Kwh battery on my DRZ and my range was around 30-35 km at a speed between 50-60 km/h in city (25%) and 75-80 km/h on country roads (75%).
So, you will probably need a bit more to acheive your 40 km range goal (maybe 3 Kwh). I suggest to you to take a look at the Calb 40Ah cells. There performance seem correct and the price is fair (24s at 1300$). For me, the extra space is more a concern than the extra weight.

Oh! and don't be worried about weight because if you compare, I used a 62 lbs motor coupled to a 13 lbs gearbox(75 lbs drivetrain).

good luck.


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## nxp (Apr 6, 2011)

Hi Yabert

That's a very clean build there. Are you still using the bike?

As you suggest I will consider the prismatics in 40Ah size. Is the price you mention directly from the manufacturer or from a reseller? I'm looking at some prices online and for 24s Thundersky 40 it adds up to 1500$+shipping. Are TS, Winston and CALB related or are they competitors?

I'm assuming that with the 40Ah cells I can occasionally run the ME0709 at up to its maximum 300A while with the single string of Headways that would damage the batteries. Is that right?

And did you have any problems with the Headway cells being mounted from the "terminals"? I'd say a motorbike environment is pretty harsh and bumpy and might need special supports for the cells?


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## Yabert (Feb 7, 2010)

nxp said:


> Are you still using the bike?


Yes.... but with the original gas burner engine now!..

TS, Winston are the same and Calb is another brand. Calb have better energy density and better reputation (maybe also better power capacity, I think).

If you tinking build a 300A controller, Calb or Headway can do the job.
Calb 40Ah are rated for 400A > 10sec. http://evolveelectrics.com/CALB.html
Two (2) Headway 16Ah (32Ah) are rated 320A continous and more than 400A for few sec.

But don't worry about peak cells Amps because those are only the same than motor amps for few sec during an acceleration.
For example, on my bike, with my 700A controller, I was only hit more than 400A for maybe 2 sec. in a 5 sec. 0-80 km/h acceleration.
With a 300A controller, the battery will probably never hit 300A (battery side).

The headway cell need a support because the negative terminal isn't really strong. See here: http://www.manzanitamicro.com/products?page=shop.browse&category_id=29


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## Tomaj (Oct 3, 2011)

I would also need some help,please

So...
-Aprilia RS125,donor bike
-Modified suspenssion, brakes, LED lights, complete Ducati 1098 fairings,ALU subframe... 
-top speed 130km/h, range 60km, overall performance compared with 250ccm 4stroke bike
-72V 60-80AH A123 20Ah cells or Turnigy LiPo
-total weight 150kg
....
What about powertrain....Motenergy ME913??

Any oder suggestion?
Budget for motor+controller is around 2000€,of course BLDC or AC, brushes are history


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