You will need to lug more like 300 lbs of batteries upstairs if you are
using lead. Six 50 pound lead acid batteries might get you all the way
there.
A transmission will not help your range and will add weight and take up
space which you will need for batteries. A transmission will let you get
better overall performance with less motor and controller, but a single
ratio 72V system with a 450 amp Alltrax controller will provide plenty of
speed and acceleration. Less than a gas motorcycle, but plenty to manuever
through traffic.
damon
From: "James Allgood" <[EMAIL PROTECTED]>
Reply-To: ElectricMotorcycles <[email protected]>
To: "ElectricMotorcycles" <[email protected]>
Subject: Re: [ElectricMotorcycles] NooB to Ecycles
Date: Tue, 6 Feb 2007 22:57:30 -0800
Thanks for the tips. I have 16 miles one way and while it may be possible
to plug in at work, it will be a miracle if I can make it happen. It would
be more likeley that I can lug 20 or 30 lbs of batteries upstairs to my
cube and charge the removeable ones while I work so I have definately been
thinking of removeable batteries, probably in saddlebags that I could use
on shorter trips for storage.
I can definately keep it under 50mph, a lot of my trip is spent splitting
lanes over the Bay Bridge. I don't really need a lot of handling, it is a
comutter bike.
I was wondering if the decrease in drag compensates for the weight and
inconvienence of a full fairing.
What no one has seemed to address is the issue of the transmission. Would I
be able to increase range by installing a transmission or at least a
centrifugal or planetary gear? I am not as familiar with the power
characteristics of an electric motor, but looking at the spec sheets it
looks like lower RPMs have advantages for torque, efficiency and power
consumption. Or does the lack of horsepower start to suck amps fast at
higher speeds no matter what RPM you run at?
----- Original Message -----
From: Andrew Wowk
To: ElectricMotorcycles
Sent: Tuesday, February 06, 2007 8:20 PM
Subject: Re: [ElectricMotorcycles] NooB to Ecycles
If you have 20 miles one-way than you just might be able to do it.
You'll need a lot of batteries, though. Shooting for anything more at
highway speeds is not a good idea unless you know how to build a BMS
(battery management system) and have enough money to shell out for Nimh,
Nicad, or lithium ion batteries. Most EM conversions will probably crap
out at less than 15 miles at freeway speeds. Keeping speeds below 50 will
really help. A Zivan charger, charging from a 120v outlet could probably
completely charge the batteries in 2 hrs or so.
With lead-acid you are pretty much stuck with a crappy range, or a
slightly-better-than crappy range. In the latter case you have to pile the
batteries on, meaning handling suffers, and the weight needs to be placed
higher in the frame making the bike a lot harder to corner.
A few ideas to play around with to maximize range:
1. Use lead-acid batteries with rectangular cells instead of spiral
wound to fit more in a smaller space. B&B are a good example.
http://www.bb-battery.com
2. Strategically pick the bike you wish to convert. The more space you
have down lower the better. You also want a light frame, and a sports bike
with plastic to reduce drag would certainly help. Design your battery
supports to put the batteries as low as possible while still maintaining
enough ground clearance. You could put batteries underneath the existing
frame cradle.
3. Pre-heat the batteries before use. I have yet to see how well this
works. An electric blanket might do the job well (running from a 120v
outlet, NOT the batteries).
4. Removable range-extender batteries of some type. This way you can
chose when your bike will feel and handle like crap to get the extra range.
Adding battery capacity results in a fairly linear increase in range, i.e.,
doubling the capacity will double the range.
good luck,
Andrew
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