After some trial and error, more error than trial, i've come to point where I am satisfied with my efforts and want to share it with the world since I've not seen many other people fuse this simple idea into reality.
I took my standard bicycle (£100) and added an electic motor kit (£250), plus sealed lead acid battery 12ah @ 48v (£90), it is great as is and can acheive 10miles with combined cycling, now that's not enough to get me work yet alone home. And I assure you upto the 12th mile this was very arduous with 20kg extra weight and flat batteries.
So I picked up a cheap bicycle trailer (£30) and a cheap petrol generator 800w from aldi for £70. The problem here is howto to tranform the mains voltage to something that the bike controller is happy with, and theres over current protection to think about also. I initially thought about using a stepdown transformer but they are expesive and hard to get at the spec i needed. I tried an arc welder, but the voltage was a little low and the current too high. I could rewind it a little but I want to get results fairly quickly, so I instead opted to use regular computer PSU used in parrallel to get the voltage needed, plus they were rescued from the skip.
The biggest problem is the motors inrush current ~35amp, the psu's I had were max 18amp, so they would go into protection mode and shutdown. I originally wanted to use the power from the generator alone, but because the psu's kept tripping I added in the battery as a buffer. I could use a resistor but the commercial products would cost hundreds (needed 3.3ohm 1080w), so I used some springs as resistors, they will probably get hot and possibly melt, I'm hoping they last long enough for me to assess the range gain I can get.
So thats where i'm at with this idea, it's not pretty or efficient this I know. My first run was 8 miles with a battery at 50v which dropped to 47v, at that point I had no bridge rectifier or resistor, and I suspect the battery was being drained first, as i was only using 4 psu's 48v.
I suspect now that the source with greatest voltage will be drawn upon first, and without the resistor on my now 5 psu's 60v it would shutdown a couple, but now it draws from the psu upto 15-18 amp ensuring they all remain on and then draws upon the battery for another 7-9 amp.
I'm thinking of adding some big cap's after the resistor to provide some burstable current as really I want to be able to operate in 3 modes, Engine Only, Battery Only and Both.
Hopefully the storm will be over and tomorrow I can get some stats.
I have a couple of videos here;
http://www.youtube.com/watch?v=rxvo0Wz3Umo
and
http://www.youtube.com/watch?v=b2WinTF1lVg
Where i'm ultimately going is for a custom tricycle like a velomobile, and an electric start generator with a custom winding so I can do away with the 4-8kg of PSU's, maybe mod the engine with HHO or a fuel vapouriser, and possibly think about a huge joule thief for auxiary lighting, and perhaps smoothing caps, and I could think about regen braking into a super cap bank.
Thats it for now, and thanks for reading.
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