Hi, New Guy here.
I'm starting a conversion of this Ninja 250
As my first build, I am concerned with $$$. I will spend what's necessary but I don't want to go overboard.
I only need 30-40mph, and a very limited range of 5-10 miles. I am a pretty good mechanic with some welding experience, but little knowledge of what makes an EV go. This is my first project although I recently reworked my 1973 Auranthetic. Enjoy:
A friend has recommended this kit from electricmotorsport.com
EMC-R 48 Volt Motor Drive Kit
Includes: E-tek-R Motor, Alltrax AXE 4834, Magura Twist grip throttle, Contactor, Wire kit, Fuse and holder.
Price...........$980
Is this a reasonable place to start? Could I bodge together something less expensive?
I also need input on choice of batteries. I am thinking about going 48V.
Thanks,
Randy
Yes that's a good start (the kit from electric motor sport). I have no idea if you could get something for less however as a first time builder maybe (voice of experience) it will be more straight forward to get a complete kit rather than hunt down all the parts yourself. Maybe for your second build you'll do something more experimental. (wink)
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
If you use the ETEK motor, you may want to consider using 72 volts, for higher speed/power. See if your proposed controller will survive operation at 72 volts-up to 400 amps can be demanded by the ETEK at this voltage, under acceleration/hillclimbing! If space/money permits, consider lithium batteries, as they generate less heat, and are lighter than Lead-Acid. (40 to 60 ampere-hour LiFePO4 batteries look promising) I have an old HONDA 250 interceptor, but have not decided what I will do with it yet!--Good luck,---Bob Curry.
Robert M. Curry
I like the idea of a faster longer range bike, but this is my first build and I'm trying to keep it simple. And, like I said, as low cost as possible.
I live in a small town and everything I need to get to is really within 3-4 miles. Nearest "city" is 15 miles away, so big jump in performance needs to get there and back.
I have heard the heat may be an issue with this motor if I tried to run it at 72V. Also, the controller in this "kit" is 24-48 Volts/300 amp. Am I going to be really disappointed if I don't spend the $150 more for the 24-72 V/400 amp controller?
As far as batteries goes, I am very undecided. How do I justify the expense of Lithium when I am building a local runabout?
Can you give me the battery 101 ?
Thanks,
Randy
Congratulations! This Etek will be a very good start.
I don't agree. He only wants 30-40mph, that's fine. My Puch Condor III uses Etek with Altrax 400 Amps at 48v. With one short speed of 60-70 km/h it performs perfect in hard up-hilling. We were forced to reprogram the controller to 200 Amps (half power) for safety purposes. On the other hand, at 72v your brushes, the big weakness of this engine, will vanish in a record time. The higher the voltage and amperage is, the quicker they are eroded.
I believe the motor I'm looking at is a brushed perm motor. Would I be better off with the Mars Brushless? I am considering upping the kit to this one:
EMC-RT 72 Volt Motor Drive Kit
Includes: E-tek-RT Motor, Alltrax AXE 7234, Magura Twist grip throttle, Contactor, Wire kit, Fuse and holder.
Price...........$1195
This would give me a 24-72 Volt 300 amp controller. I still would probably only go for 48V for now as I don't need the speed or the range, but I can see that as my budget allows I will probably want to upgrade almost immediately. At that point I could do a lot by just adding batteries.
I still have the battery question though. What configuration and what type?
I would reccomend the Mars RT 72 volt motor. Also 400a Kelly Controller with regen, ultra smooth, reliable and low cost. If you want to keep costs down, go with PowerStar 12 35ah batterys from Powerstars web site. They are $52 each. I have almost 2k miles on mine and countsing.
Phil
That would be ok.
Mars don't have brushes but they have less torque, a friend had some problems with one mars and some broken kellys, finally decided to use a brushed engine. They are more reliable.
This is the final result: http://www.evalbum.com/1387, ask him about his experience.
Hi, I tried out the Mars brushless, not the Etek-clone R/RT versions, and well the performance was OK but nothing impressive.
It seems like the takeoff is underpowered because of the hall-effect sensors, resulting in poor torque at very low speed, wich is not what I was expecting for my off-road machine. Also I think the efficiency of the brushless motor drops dramatically over 100-150 amps, the Mars BLDC is not intended for high torque output. You could improve that increasing the voltage, since there's no RPM limit on these kind of motors, but you will need a gearbox or dual stage fixed transmission for 30-40mph and that will kill the efficiency gain. I had troubles with the Kelly brushless controllers, I believe there are better solutions for controlling PMAC motors, like those made by Sevcon.
After returning the stuff back to the supplier, I tried the classic-but-great Lynch design and the difference was clear, I decided that having to replace brushes was not a problem, the torque at very low speed is awesome and the overall effciency has to be better; I have more range with the same batteries and gear ratio.
Dear Santiago,
Thanks for sharing your experience, and wellcome to this forum. Sure you'll find great stuff here.
regards
Roger