| Author |
 Topic  |
|
|
gotwind
Forum Admin
United Kingdom
1564 Posts |
 Posted - 29/07/2008 : 21:58:20
|
Having recently 'road tested' a modern electric bicycle, they are pretty impressive.
Surprisingly good torque and max speed of 20 m.ph - plenty available but not that cheap, there may be bargains to be had..
I have plenty of 55w solar panels available to recharge the battery, one mounted on the rear of the bicycle would give a reasonable charge.
Or a daily home charge from the 440w solar panels I have available (8 panels).
I forsee a couple of problems.
My solar panel is 12v, most electric bicycles run on a 36/48v battery system - possibly Lithium Ion, tricky to charge - any ideas?
Theft, leaving a solar paneled electric bicycle in a sunny area whilst at work e.t.c - damn thieves 
My first attempt here
http://www.gotwind.org/diy/solar_electric_bicycle_project.htm
Ben.
|
|
|
BushWhacker
Junior Member
Canada
359 Posts |
Posted - 30/07/2008 : 01:03:57
|
First off Ben I'd go with NiMH batteries because they are darn near bullet proof. They don't care if they get run dead flat 0 volts.
As for the charging I would be inclined to go with panels (that collect energy all day while you are at work) connected to a 12 volt battery bank to an inverter. Plug your bike in with a commercial charger when you get home (and it's getting near dark).
I know there are efficiency losses from DC to AC and back to DC but the only alternative I can see is running your panels in series AT WORK. But then your are limited on the week end.
BTW there are at least a couple of E bikes in Calgary running 96 volts with a top speed of 60 mph. Not legal and not too safe either, mind you the cops on Mountain bikes probably won't catch you. I don't think Lance Armstrong is on the police force.
Everything should be made as simple as possible, but not one bit simpler. - Albert Einstein |
 |
|
|
Capt Slog
Junior Member
United Kingdom
262 Posts |
Posted - 30/07/2008 : 08:44:14
|
I've been thinking of converting my bike to 'electric help' too.
I see that you are driving on the front tyre, and wondered if you'd considered a more direct approach.
The bike I have has three front chain-wheels, to give the (ridiculous*) 18 gears. It would be no problem to rig the front deraileur system so that it only used the upper two chain-wheels and then run a a small loop of chain around the unused one to a motor. To make it simple, the motor sprocket could be free wheeling, or if one wanted to make it more complicated it could be made to regain power under braking.
(* how did I manage all those years ago in my teens, when I only had 5, and rarely went under number three?) |
|
|
|
BushWhacker
Junior Member
Canada
359 Posts |
Posted - 30/07/2008 : 15:21:13
|
From what I have seen and read the best way to go on a conversion is with a wheel and hub conversion kit. A fellow who has owned several Ebikes told me that regen didn't start until 32 kph (about 20 mph) so there was very little charging done on a ride that didn't involve going down a big hill.
Here's a ton of links. (hint: the farther down you scroll the more European links you find)
http://www.fleettrikes.com/links.htm
Edited to add: Ebrakes here (link on the left under "Conversion Kits") http://www.crystalyte.com/
Cheers!
BW
Everything should be made as simple as possible, but not one bit simpler. - Albert Einstein |
Edited by - BushWhacker on 30/07/2008 15:27:00 |
|
|
|
BushWhacker
Junior Member
Canada
359 Posts |
Posted - 30/07/2008 : 15:47:57
|
Skimming through the links above I found this page.
http://www.users.bigpond.com/solarbbq/bikesale/bsale.htm
It answers a lot of questions on Ebike conversions, hopefully some of yours.
Cheers!
BW
Everything should be made as simple as possible, but not one bit simpler. - Albert Einstein |
|
|
|
gotwind
Forum Admin
United Kingdom
1564 Posts |
Posted - 30/07/2008 : 21:28:49
|
Wow,
That is a very thorough Australian Electric Bike Hub Motor Kit web site.
I wonder if I can get a decent electric bike for under £100 ($200 U.S).
I will try..
Thanks BW
Ben. |
|
|
|
BushWhacker
Junior Member
Canada
359 Posts |
Posted - 30/07/2008 : 23:21:24
|
In Canada (the land of EVERYTHING costs more) the kits start at about thrice that for Crystallite kits.
Brushed $600 36v on Lead acid.
Brushless $650 36v Lead acid 25km range, $1100 Lithium polymer 40 km range.
Weight seems to be the biggest factor in range. I also read a wee bit about weight being really hard on aluminum bike frames.
They also seem to be avoiding NiMH for some reason. I'm guessing its a case of low $, high $, with nothing in between.
The dealer in town is also looking at getting an EV kit for cars imported. The lithium pack, an only the battery pack for that sits at $10K *Cough cough*
Cheers!
BW
Everything should be made as simple as possible, but not one bit simpler. - Albert Einstein |
|
|
|
Tim
Junior Member
156 Posts |
Posted - 31/07/2008 : 15:45:32
|
Bushwhacker - Oooh, ooh ....is it me or would that 850W brushless 36/48V "408 Crystalyte" hub motor be a serious contender for a low-RPM genny if it were only a bit cheaper? Finger in the air, 30KM/h on a 26" dia wheel would be around only a couple or three hundred RPM? Though ball races rather than thrust bearings I expect. One of the design criteria ought to be low cogging for when the power isn't on, I would have thought.
Shoot me down if I've missed something or dorked out by a power of ten somewhere! |
Edited by - Tim on 31/07/2008 16:00:25 |
|
|
|
BushWhacker
Junior Member
Canada
359 Posts |
Posted - 31/07/2008 : 18:34:19
|
Hi Tim,
I actually have a smaller Crytallite hub under a small (16" wide by 2' tall) Savonius. Small as in too small. I thinking about a Lenz 2 or Benesh about 2' wide by 3' tall and give that a whirl. In some pretty pronounced winds (25+ mph) she spun up pretty good and made some decent power but it needs more torque than that little Savonius has.
The Crystallite hub I have is a brushed 36V model that I bought for a bit under $200 because some components of the kit were missing. (worth checking out?) The hub has a fair bit of cogging as the magnets are set square. If you short the hub and spin the wheel by hand you can feel the cogging to some extent through the rim. I crunched numbers quite some time ago and came up with roughly 85 RPM for 12V if memory serves me. If you are a super sleuth you might be able to dig up a thread on here.
Here are some photos.
That's about all I can tell you Tim, I hope that helps.
Cheers!
BW
Everything should be made as simple as possible, but not one bit simpler. - Albert Einstein |
|
|
|
Tim
Junior Member
156 Posts |
Posted - 31/07/2008 : 20:20:15
|
Now that's a nice setup you have there and I love the elegant engineering. Beautiful job.
Been toying with the idea of plonking a VAWT together after I move house, at the moment though I only have a badly-cogging 1KW stepper motor that Gordon's RenewableComponents flogged off cheap, which would need gearing up too much (I think it's 12V per 110RPM).
Anyway, am still waiting for some reasonable winds in my area (wind-shadowed from anything even slightly southerly) to give these 10ft 6in fibreglass CMS Magnetics HAWT blades of mine a good try-out, now that I've remounted them after nailing in Myk's 150A (absolute max) 24V solid state unit in place of the 60A 12V relay unit that knackered in some Spring gales over here. And of course sticking an extra 400W of dump in circuit so the batts don't boil like last time!
With more and more electric vehicle propulsion coming on stream, I'm really looking forward to the secondhand and spares availability that ought to follow it. |
Edited by - Tim on 31/07/2008 20:43:13 |
|
|
|
optixelectrics
Junior Member
United Kingdom
103 Posts |
Posted - 31/07/2008 : 20:45:35
|
Tim,
The 408 is the very same 408PMG used in the futurenergy 48V 1kw wind turbine (with a couple of case mods). Retail on these is about £125 trade.
Also, please let me know how you get on with the controller!!
Myk
Goto www.optixelectrics.co.uk and click on 'renewable' for Dump Load Controllers, Turbine and battery monitor units. Grid tie installations. Custom projects catered for. |
|
|
|
gotwind
Forum Admin
United Kingdom
1564 Posts |
Posted - 31/07/2008 : 21:19:59
|
Interesting insight Myk if correct.
Ben. |
|
|
|
BushWhacker
Junior Member
Canada
359 Posts |
Posted - 01/08/2008 : 02:33:17
|
Tim wrote "Been toying with the idea of plonking a VAWT together after I move house, at the moment though I only have a badly-cogging 1KW stepper motor that Gordon's RenewableComponents flogged off cheap, which would need gearing up too much (I think it's 12V per 110RPM). "
What I would suggest is think tall and thin for your VAWT. That will help with the RPM and still provide the profile (sq ft) in the wind.
Something I tried that I believe helped was a small rubber coupler between the VAWT and gen unit. It lets the VAWT have a little run at the first cog and then the wind takes over. In my case I simply used about 6" of rubber hose clamped to the bottom of the output shaft and the top of input shaft of the hub.
BTW with no load those hubs have very little resistance. When connected however...
Cheers!
BW
Everything should be made as simple as possible, but not one bit simpler. - Albert Einstein |
|
|
|
Tim
Junior Member
156 Posts |
Posted - 01/08/2008 : 13:01:58
|
Myk
As promised, if I ever get any wind from the right direction!
Bushwhacker
Thanks for info, tall & thin it will be when I get around to making it
Tim |
Edited by - Tim on 01/08/2008 13:04:01 |
|
|
| |
Topic |
|
Solar bicycle conversion idea