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nolen
21 August 2010, 1543
I built an electric motorcycle from a 1986 Honda VF700F, turning it into a NolenV96400A.
I am now rebuilding it since I know much more about conversions and plan to add LiFePO4 batteries.
The plan is to have a motorcycle that gets 120 miles range at 70 mph. All the while performing like it did stock. For anyone who knows EVs, this is a challenge, though I am up to the task. My passion for electric vehicles lead me to get a job with KTA Services, Inc. I am very grateful for the opportunity to work with Wistar, he has proven to be a great teacher and employer. I look forward to making new friends who share the enthusiasm for EVs that I have.

electriKAT
21 August 2010, 1630
A VF700 is not a cruiser. It's very similar to Travis' bike.

Can anyone get a ballpark figure on how much energy is required to do 120 miles at 70mph?

electriKAT
21 August 2010, 1712
Yeah, the VF (interceptors) and magnas used the same engine, but different frames. The manual for my interceptor included the magnas too.

magicsmoke
21 August 2010, 1720
Can anyone get a ballpark figure on how much energy is required to do 120 miles at 70mph?

Don't know the frontal area or drag coeff. for this bike, but 15 KWh ish I think should do it.

Rob

p.s. used Lennon Rodgers' spreadsheet for this. So if the numbers are off it's likely my input :)

electriKAT
21 August 2010, 1738
I realize you have to make a lot of assumptions. I haven't run any numbers, but my gut tells me that's on the low side.
Assuming it's close, has anyone ever gotten 15kwhr into a motorcycle frame before?

magicsmoke
21 August 2010, 1753
I realize you have to make a lot of assumptions. I haven't run any numbers, but my gut tells me that's on the low side.
Mine too, but 70mph is just in the grey area before you start having to pay heavily for speed because of drag.


Assuming it's close, has anyone ever gotten 15kwhr into a motorcycle frame before?
Dunno. Think Motoczsyz ran about 12.5 KWh in this year's TT Zero

larryrose11
22 August 2010, 0430
what are the rules governing wheel base? can the frame be stretched, and the seat / tank be lowered? Lowering the tank will lower the frontal area when in a tuck, and lengthening the frame = more room for batteries. For a racing application, are wheel motors out?

Lawlessind
22 August 2010, 0630
Nolen,

Congratulations on working at such a fine establishment. I have dealt with KTA for over ten years and they have always been very professional as well as helpful. I made some assumptions based on experience and used the Wallace calculator. I show 8.5Kw required assuming level ground to get 70 mph. The very best eff. I ever achieved was with a specially prepared Lemco D135 R motor. This delivered better than 90 percent of the battery power to the drive sprocket as well as excellent regen capability. It will run happily anywhere under 120 volts. Assuming the 120 miles is the max range than accelerating to 70 mph and holding it steady for 120 miles on level ground AND assuming 85% overall eff. with no headwind should require 15 kwhr. This is a lot of battery to stuff in a bike but can be done. I have seen it before. The catch I'm afraid is that the bike performance and handling are going to suffer from the bulk and weight of the battery pack. Using a larger motor and controller will solve the performance issues, but there goes your range...... This is definitely a challenge for you. Good luck and welcome to El Moto!

Nuts & Volts
22 August 2010, 0653
I think you need about the 15KWh mentioned earlier to do. maybe 16 because I didnt increase the weight of my bike (for more batteries). That is a hell of a goal. The Chevy Volt has 16KWh of batteries and the whole pack weigh about 400 lbs with cooling and everything else that you may not need on a bike.

So if you can make the frame as light as possible and as streamlined as a hayabusa then i think it CAN be done. But space is going to be an issue, maybe a hub motor is necessary.

Good luck
Kyle

magicsmoke
22 August 2010, 0754
Ok, assuming that 15 KWh is the ballpark, I used 24 Thundersky 200 Ah cells and an Agni (any model will do) in the spreadsheet. That's about 400 LBs.
Removal of the ICE and exhaust etc. should account for most if not all of that.
The controller only has to be a quite modest 150 A (Higher obviously for accel.)

Don't think anything drastic frame wise is necessary, maybe fill in and round off the 'gone' radiator area, remove mirrors blah, blah and employ a gynaecologist to help with the battery location as his knowledge of squeezing things in and out of tight gaps should prove invaluable!

Sounds doable, glad I'm not paying for it though!

Rob

chdfarl
22 August 2010, 0906
Ed pointed out the biggest issue. That is to identify what type of racing your aim to try. The VF is a very antiquated race design as a race bike. I race a vf 500 so I know first hand. They were cutting edge in the 80s but the suspension and wheels are weak for road racing. My 500 gets out of shape easy with my skinny a$$ on it and that model was renowned for its handling. The wheels are 16 front and 18 in the rear but modern race tires are only 17 inch. either way weight would be a priority.

Nuts & Volts
22 August 2010, 1005
Ok, assuming that 15 KWh is the ballpark, I used 24 Thundersky 200 Ah cells and an Agni (any model will do) in the spreadsheet. That's about 400 LBs.
Removal of the ICE and exhaust etc. should account for most if not all of that.
The controller only has to be a quite modest 150 A (Higher obviously for accel.)

Rob

Magicsmoke I dont think that any engine+exhaust will weigh 400lbs. I think frame will at LEAST weigh 180lbs so thats a 580 lb bike + a riding. Racier at over 700 lbs is probably not going to be fun. TS are not going to cut it for this kind of project. I think LiPo might be the only way to go.

magicsmoke
22 August 2010, 1235
Magicsmoke I dont think that any engine+exhaust will weigh 400lbs. I think frame will at LEAST weigh 180lbs so thats a 580 lb bike + a riding. Racier at over 700 lbs is probably not going to be fun. TS are not going to cut it for this kind of project. I think LiPo might be the only way to go.

You're absolutely right. It was a heavy beast though 485 lbs dry.

As for the TS, again without knowing what this 'race' bike is meant to be doing, it's ridiculous to try and spec it.

The plan is to have a motorcycle that gets 120 miles range at 70 mph. All the while performing like it did stock.
what does that mean !?

but to provide the power for 70 mph, the 200 Ah TS cells would be running at just over 0.6 C, they'd be fine. Sure, bulkier than the fabled Kokams.
Anyway, as the thread asked, it was to get a 'ballpark' figure, so something had to go in the spreadsheet battery weight box. :)

Rob

Nuts & Volts
22 August 2010, 1244
Ok yea I see where you are coming from magicsmoke. I agree with what you're saying now and understand your calculations and all.