# EV motorcycle questions



## n8thegr8 (Feb 11, 2008)

well, looking at evalbum, seems like for that kind of performance, you'd have to go with a 72v system like http://www.evalbum.com/1497 or http://www.evalbum.com/1562. You could prolly swing it pretty cheap with lead acid's if you could charge at work. Not even the Lithiums that the chick with the first bike got that kind of range. I could see it happening if you could somehow find a way to fit 12 6v 225Ah batteries on there or something, but then that's getting pretty heavy. All in all, it'll prolly end up close in cost to getting a cheapo car with a blown motor and converting it, although a bike with those specs would kick ass! Also, I'm by no means an expert, so take what I have to say with a grain of salt, lol.


----------



## muzein (Mar 22, 2008)

So I've been looking and it seems pretty impossible without charging at work. I work for the state so that could be tricky. They'd probably want me to submit some obscure forms and no one in the state will make a decision on it for a year or so.

Anyhow - another question.
Why don't they make bikes with variable speed pulleys, or some form of transmission?
I know I don't understand electric motors as much as I want to but it seems to me that the optimal gear ratio would change as the RPM's and speed increased. So why not change the gear ratio at higher speeds. Wouldn't that allow you to achieve higher speeds with less draw on the battery?

Also, Is this not a good forum for answers? I was hoping for a bit more activity.


----------



## Damon Henry (Jul 26, 2007)

Hi,

I've been riding my electric motorcycle for several years now. http://www.evalbum.com/497. You will not be able to do 54 miles on a $2000 budget. You will not even be able to do 27 miles on that budget. You will be able to do 10 - 15 miles if you find lots of surplus parts, but that will not accomplish what you want. If you are sticking with lead acid batteries I can pretty much tell you what range you can acheive by the weight of the batteries you put on. 200 lbs of lead acid will net you between 10 and 15 useable miles, closer to 10 at freeway speeds. If you move to other chemistries you can achieve better range, but the cost goes way up. Your only chance of getting a motorcycle that can do that kind of range at those speeds is some flavor of Lithium batteries.

As far as the question about the gear ratio's. The reason most EV motorcycles do not have some kind of transmission is because the effort is not worth the gain. You may gain a little in range, and depending on how many amps your controller can push a lot in performance, but space is really tight when building a motorcycle, and the need for a transmission is not that great. It's easier to just buy a more powerful controller. In motorcycle size the cost difference is only a couple of hundred bucks, and it does not require any more space. A 72 volt 450 Alltrax controller will give you great performace from 0 to well over 60mph with a single gear ratio.

damon


----------



## ngrimm (Oct 19, 2007)

I've been thinking about a motorcycle conversion too so I have looked at nearly every m/c the Evalbum. I noticed that the range is surprisingly low on most all of them compared to the cars. like maybe a third. Even though the cars weigh five or six times more including batteries. Why do you think that is? Is it because you can't safely use the same proportion of batteries without exceeding the weight capacity of the bike? Norm


----------



## sharp21 (Mar 11, 2008)

As far as charging at work, have you asked anybody about it?
Alternatively, you could get one of those metres that measures exactly how much electricity you are using, then just plug in while you are there & drop a nickel on your boss's desk every morning!
S.


----------



## Damon Henry (Jul 26, 2007)

There are a couple of significant range issues. The first is the placement and the weight of the batteries. The first go round of my bike actually had a 30 - 40 mile range. This was with 8 6 volt Saft STM100 Flooded Nicad Modules. Total weight of batteries was about 230 lbs. Not only did the bike feel too heavy, but locating the batteries gave me other problems. It did have tons of range however, which really let me get out and go. After those batteries pooped out, I decided that I wanted a less bulky lighter weight pack and sacrificed range in order to acheive that. It made everything else much better  With lithium you can have both. All I need is about a $7000 investment in lithiums to have something much better than the original setup I had with the Safts, but I decided long ago that spending thousands of dollars to upgrade my 1974 250 Suzuki was out of the question. Instead I built my truck. If anything is going lithium it will be that.

The second issue with motorcycles is aerodynamics. At freeway speeds they just aren't that much more efficient than cars. It's tough to find a stock motorcycle that gets better gas mileage than my Honda Insight Hybrid. So when you account for their inefficient aero, and the lack of space and suspension for bulky batteries you find out that you really have to work hard to get better than 20 miles range out of a motorcycle. You have to either spend lots of money on expensive batteries, or lots of time and effort on custom frame and suspension modifications.

damon


----------



## ngrimm (Oct 19, 2007)

Hey thanks for sharing your experience Damon. I have also noticed that about gas mileage on motorcycles. Not that much better than a small car. Sorry if I hijacked the thread but figured others have wondered about this too. I have been thinking about converting a larger v-twin style bike like a Honda Shadow etc. since it is would probably handle the weight and would have lots of room for batteries. Maybe not a Shadow due to the shaft drive. The other thing that is obvious in looking at m/c in the evalbum is that most run much lower voltage than the cars which I imagine is due to the fact that four lead acid 12v batteries only gives you 48 volts. What effect if any do you think that has on performance and range? Norm


----------



## Damon Henry (Jul 26, 2007)

Range is really a function of the weight of the batteries, so the voltage configuration is not as important. A motorcycle with 6 33 pound batteries will have the same range as a motorcycle with 4 50 pound batteries even though one is running at 48 volts and the other at 72. The higher voltage does make a single gear ratio much easier to live with. I would definitely go with a 72 volt system. It's really easy to make a motorcycle with 20 miles range and good performance this way. An Alltrax 72 volt controller, a 6.7 inch ADC motor and 6 50 lbs AGM batteries is all you need. The batteries will be a tight fit, and locating the 300 lbs of weight in a way that feels good is tricky, but that is the hardest part of a setup like this. Lots of people like the pancake style motors as they are about half the weight and sometimes easier to mount than the forklift style, but I've heard of too many of the pancake style (eteks etc..) which have melted down for my taste. I would stay away from them. A good rebuilt forklift pump motor from Jim at Hi Torque Electric will take all the abuse you can throw at it.

You can of course go with even higher voltages, but 72 volts is the top of the golf cart, forklift technology, so then you start getting into lower production EV specific parts which cost quite a bit more money and often come with a significant wait.

damon


----------



## b.koen (Mar 9, 2008)

I would like to thank all that posted to this thread. I told myself awhile back no more motorcycles. limited ride time in my area. I was a fare weather rider. After deciding to go ev I started to consider another bike, this time ev. I need/want the freeway speed for 34 miles round trip. Lithium I guess is the only real way to get there. Cost benefit just isn't there for me. Back to the 4 wheel variety I think. Again thank you for the honest limitations of a e-moto.


----------



## mattW (Sep 14, 2007)

A 48V 100Ah pack from LionEV is only $3000, I'm thinking of doing a bike conversion with one. A 70.4V pack would cost $4400. Considering you'd get double the range of LA and you'de have 100Ah I think you could get some serious range out of it. At 125wh/mile you'd get 35 miles out of the 48V, and 55 out of the 72V. Be close to the weight limit but I'm pretty impressed by the pricing!


----------



## ngrimm (Oct 19, 2007)

The lithiums would be nice but would be way out of my budget. I emailed a gentleman by the name of Kyle Dansie on the evalbum since he converted a Ninja like I am planning to do. Here is his response regarding the range with lead acid batteries: 
"Very good question that most people do not bother to check into. The 45 mile number is accurate, I really did drive it that far. 
However I need to tell you the complete story about testing I did that day.

First of all that was on my first battery pack ( Costco batteries ). This first pack only lasted 700 miles. Part of the reason may have been my long range test that weakened them. The other reason is they could have just been poor quality batteries. 

I now have Trojans and they seem much stronger, however I will not drive them till they die because I want them to last a long time. 

The second thing about the test was that I was doing 10 to 12 mile loops. After a loop I would stop back at the house record the mileage and the voltage and let it rest for 10 or 15 minutes and then go do another loop.

At the time I did not know, but a rest period will let the batteries recover some voltage just from sitting. If I had tried to do 45 miles in a single ride it would not have made it that far. "

He is using six group 24 size batteries which are 85ah but I plan to use six of the group 27 which are 105ah and at 135 w/hr per mile that calculates to 60 miles so 40-50 shouldn't be out of the question. My point is that if you pick a bike that has room enough for the batteries and also can handle the weight you could do ok. Kyle's bike only gained 25lbs over stock so it is at 520lbs and the gvwr is over 950lbs so it's not overloaded by any means. I am thinking I could add two more batteries at 50lbs each to the back and still not be over the limit. My point is that it seems like choosing the right bike for what you want to do is just as important ans choosing the right car for a conversion. Norm


----------

