Search found 159 matches

by cerewa
Oct 09 2008 1:48pm
Forum: Battery Technology
Topic: EEStor ultracapacitor
Replies: 181
Views: 15760

Re: Zenn gearing up for EEStor-powered car

Let's see. A 1 KWH battery could charge up in 5 minutes with 12KW of power. For perspective, At 120 V average, that's only 100 amps average. So it doesn't sound electrically difficult. In terms of current infrastructure, this is questionable. I think the houses in the USA that have 240V hookups (fo...
by cerewa
Oct 09 2008 1:07pm
Forum: E-Vehicles General Discussion
Topic: Riding my e-scoot again, and cops saw me
Replies: 28
Views: 3481

Re: Riding my e-scoot again, and cops saw me

You guys ever thought about a pellet stove ? I'm heating 2000 sq. feet for about 2.50 can. per day. The house has electric heat but I never turn it on! Electronic thermostat...Set it and forget it. POPS Jeez, I need one of those. I've got a tiny apartment, maybe 500 sq.ft., and in midwinter it's ab...
by cerewa
Oct 09 2008 12:51pm
Forum: E-Vehicles General Discussion
Topic: 19 new 100 mile range electric cars announced
Replies: 8
Views: 1326

Re: 19 new 100 mile range electric cars announced

Their goal is to get the price down to below Lead Acid within 2 years.
Haha, just imagine if $100 would buy ten or twenty packs with the same capabilities as the DeWalt/A123 packs, instead of one.
by cerewa
Oct 06 2008 3:10pm
Forum: E-Bike General Discussion
Topic: Coroplast for a battery box?
Replies: 10
Views: 1099

Re: Coroplast for a battery box?

FYI coroplast has pockets of air inside it. It'll insulate a little like double paned glass does.

If you use lexan (solid plastic) it will allow your battery to cool itself off a little better.
by cerewa
Oct 06 2008 12:20pm
Forum: E-Bike Technical
Topic: Modifying PWM to increase torque
Replies: 11
Views: 1008

Re: Modifying PWM to increase torque

According to ebikes.ca, I_motor = I_battery/D, so by naive inference, an infinitesimal D would result in a nearly infinite motor current thus nearly infinite torque! Bad formula. They meant to say I_motor = I_battery * D Where D (duty cycle) is a number ranging from 0 to 1 and I_battery is the "cur...
by cerewa
Oct 02 2008 3:55pm
Forum: E-Bike Technical
Topic: More powerful controller than necessary, Issue or Non-issue?
Replies: 8
Views: 768

Re: More powerful controller than necessary, Issue or Non-issue?

I think that if I could get or make some heat proof brush holders, I could pull 2000 watts through each motor for an hour without any problems. As it is, I can pull 2500 watts through each one for about 2 minutes continuous before the brush holders start to melt. I think if your brush holders didn'...
by cerewa
Sep 24 2008 3:46pm
Forum: E-Bike Technical
Topic: Need replacement spoke
Replies: 11
Views: 915

Re: Need replacement spoke

I would suggest you go to a local bicycle shop and ask them to sell you a spoke.

If you want to avoid breaking spokes again, you should then have a knowlegeable wheel builder check all of your spokes to see that they aren't too loose or too tight.
by cerewa
Aug 26 2008 2:22pm
Forum: E-Bike Technical
Topic: Magnetized Wheel (A Theory Thread)
Replies: 79
Views: 7706

Re: Magnetized Wheel (A Theory Thread)

Think watts.
1000A * 1V = not very dangerous.
by cerewa
Aug 13 2008 6:23pm
Forum: E-Bike Technical
Topic: Ultra Caps?
Replies: 106
Views: 14110

Re: Ultra Caps?

I was thinkin about using A123 cells as a substitute for ultracaps.

A123s paralleled with cheap low-C-rate LiFePO4 seems like not a bad idea to me...
by cerewa
Aug 12 2008 10:33pm
Forum: E-Bike General Discussion
Topic: 2WD winter bike with studded tires...
Replies: 20
Views: 2244

Re: 2WD winter bike with studded tires...

A 20 or 24a battery pack would do the job,the wieght adding to traction. With some exceptions (like sinking your narrow tires through snow to solid ground) you'll get better traction with lower weight (assuming same tire size). Typically, the more square-inches of rubber on the ground (per 100 poun...
by cerewa
Aug 08 2008 1:06pm
Forum: E-Bike Technical
Topic: Drat! Got My First Flat
Replies: 63
Views: 7405

Re: Drat! Got My First Flat

Interesting. Does anybody know of any studies comparing flat rates for pneumatic tires at high pressure versus low pressure for any kind of vehicle? I doubt there are any studies, at least with respect to anything resembling bicycle or e-bike usage patterns. I can tell you what the anecdotal eviden...
by cerewa
Jul 25 2008 11:26pm
Forum: E-Bike General Discussion
Topic: Some dumb safety questions for the expert E-bikers
Replies: 40
Views: 4113

Re: Some dumb safety questions for the expert E-bikers

biking on the sidewalk is safe enough at intersections if you are going less than 5mph. When there is no driveway or road to cross, (and no pedestrians) you're safe going at regular bicycle speeds. Chances are very slim you'll get a hard time from the cops for being on the sidewalk, because they pro...
by cerewa
Jul 25 2008 11:21pm
Forum: E-Bike General Discussion
Topic: Some dumb safety questions for the expert E-bikers
Replies: 40
Views: 4113

Re: Some dumb safety questions for the expert E-bikers

rear facing 12 volt xenon strobe. very bright.
by cerewa
Jul 23 2008 2:29pm
Forum: E-Bike Non-hub Motor Drives
Topic: Using RC motors on E-bikes [Archive]
Replies: 1244
Views: 168125

Re: Using RC motors on E-bikes

As regards dual motor - you can only take it so far. Each motor has a parasitic load (no load current) and if you are running 2 motors you are essentially wasting twice as much power right away - this can pale into insignificance but until you draw so much current it doesn't - you are onto a losing...
by cerewa
Jul 21 2008 9:07pm
Forum: E-Bike General Discussion
Topic: oops,.. i hope i didn't buy the wrong bike.
Replies: 15
Views: 1676

Re: oops,.. i hope i didn't buy the wrong bike.

http://www.scootonthis.com/prod_parts_2.html
3 speed freewheel. (use control+f to find it)

yes, you can spread a steel fork or rear triangle a little.

If you want, you should be able to fit a 1 speed freewheel on to any hub that'll take a 3 speed freewheel I think.
by cerewa
Jul 21 2008 7:15pm
Forum: E-Bike Non-hub Motor Drives
Topic: Using RC motors on E-bikes [Archive]
Replies: 1244
Views: 168125

Re: Using RC motors on E-bikes

Gears seem far better suited for that than electrical switching does though... I don't see why it is so hard to run a motor through the standard drive train, all it should take, is a jackshaft, that has room for three gears. It's not very hard at all to wire up a switch that turns a cheap 12v30ah L...
by cerewa
Jul 19 2008 5:54pm
Forum: E-Bike Non-hub Motor Drives
Topic: Using RC motors on E-bikes [Archive]
Replies: 1244
Views: 168125

Re: Using RC motors on E-bikes

to get a brushless motor to behave as though it is being driven through a multispeed gear system, of course, all you have to do is change the voltage. And have a controller that can handle the differing voltages. 1) Use a DC-DC voltage-reduction converter and have a switch that either runs the power...
by cerewa
Jul 19 2008 11:04am
Forum: E-Bike Non-hub Motor Drives
Topic: Using RC motors on E-bikes [Archive]
Replies: 1244
Views: 168125

Re: Using RC motors on E-bikes

.if the standard derailler is "good enough" to be your multiple gear transmission system why not use it? In my opinion, the standard derailer is not "good enough" to be the "perfect e-bike". I have a cyclone kit and you are right that it's a kind of silly design - the reason it's a kind of silly de...
by cerewa
Jul 16 2008 8:54pm
Forum: E-Bike General Discussion
Topic: kbarrett's ebike
Replies: 3
Views: 617

Re: kbarrett's ebike

a 500 Watt 40x motor If he's running 74V and 21 amp (i'm assuming that was amp hour you meant) batteries, then with a 20 amp controller it's 1500 watts and with a 30 amp controller it's 2200 watts (batteries at < 1.5C discharge). You can go pretty fast on 2200 watts, but eventually the exponential ...
by cerewa
Jul 13 2008 8:15pm
Forum: E-Bike General Discussion
Topic: NEW 3 Freewheels bike from Cyclone
Replies: 17
Views: 1865

Re: NEW 3 Freewheels bike from Cyclone

My guess is that someone will come up with an RC motor based geardown motor that blends into the drivetrain in such a way as to make everyone go "wow", but I don't think we're there yet. I'm still really interested in the idea of setting a motor (rc motor probably) to run off of two different volta...
by cerewa
Jul 13 2008 7:59pm
Forum: E-Bike General Discussion
Topic: if you want to take you bike on the train...
Replies: 9
Views: 1285

Re: if you want to take you bike on the train...

yer your american trains are bigger and better than our english trains. i've been on one in new york - long island. in the UK service varies but on my line you will soon only have 3 bike spaces per train. overcrowding is epidemic here as we have an open door policy which states that the train is no...
by cerewa
Jul 12 2008 10:10am
Forum: E-Bike General Discussion
Topic: Possible to hang a battery from triangle suspension spring?
Replies: 6
Views: 751

Re: Possible to hang a battery from triangle suspension spring?

It seems likely that it's safe, (hanging the battery from the spring) provided you regularly (like, every ride, at first) check the straps you use to hang it from the spring.

Good call on avoiding side load on damper, Mark.
by cerewa
Jul 11 2008 3:55pm
Forum: E-Bike Technical
Topic: Aerodynamics thread?
Replies: 131
Views: 16824

Re: Aerodynamics thread?

How do you go up and down gutters/kerbs on all these recumbenty thingys? The same way you go up and down gutters/curbs in a porsche - you don't. I ride an upright bike but it has no suspension and I try to avoid taking bumps, up or down, of more than 1 inch (or 3 inches if i'm going really slowly)....
by cerewa
Jul 11 2008 11:02am
Forum: E-Bike Non-hub Motor Drives
Topic: Using RC motors on E-bikes [Archive]
Replies: 1244
Views: 168125

Re: Using RC motors on E-bikes

Safe - my bike is a good example of a setup where pedaling being the direct-drive and motor being "secondary" is a good idea. It is the standard cyclone 500W setup except that I left out the crank-freewheel, which would have allowed me to stop pedaling when the motor is operating. So on my bike, the...
by cerewa
Jul 08 2008 9:33pm
Forum: E-Bike General Discussion
Topic: Charging Station Idea
Replies: 7
Views: 917

Re: Charging Station Idea

oh don't get me wrong, i can charge at work, our company is all for it. i just have to throw an extension cord out the window of my office to my bike outside. electric is free to our company on this site. although the site don't know i charge at work! i just wanted to see if they would enhance thes...