48/56V generator and science-fair wind
By bennelson, Section Newbies Posted on Fri May 08, 2009 at 03:34:25 PM MST
Looking for info on building 48/56V generator

Hi Everyone! I am pretty new to all this but have long had an interest in renewable energy generation. Two summers ago, I built an electric motorcycle, and last summer, I built an electric car. The range on the motorcycle is about 30 miles - but that's only if I am driving slow. It's probably about 20 miles if driving faster. Plus, I need to get back home from wherever I went on the same charge. That means the cycle can really only go 10 to 15 miles out. It is running on 4 Optima Yellow Top AGM batteries (55ah each) in series as a 48V system. What I would like to do is build a "range-extending trailer" I would have a gasoline engine (or possibly diesel or ethanol) power a generator that could feed power to the batteries. I would hook up the trailer to the cycle for longer trips to extend the range of the electric vehicle. It would more or less convert the cycle into a serial-hybrid. I am not planning on having the generator provide all the power for the cycle, just SOME of it, to keep the cost down. While I don't actually have  an ammeter on the cycle, the car takes about 100 amps to cruise, so I am guessing the cycle is about half that. So maybe 75 amps to cruise while pulling a little trailer? So what I need to find out is how to build/modify a generator that will output about 56V (14V for charging x 4 batteries in series) I have heard that an older-style alternator can be modified with a custom external voltage regulator to output higher voltage. That's all a little over my head though! I'm not even really sure where to start on this, but it looks like this is the best web forum out there for this kind of thing. All advice is welcome! Just help point me in the right direction! Thanks, Ben http://www.evalbum.com/1133 http://www.evalbum.com/1595 http://web.mac.com/benhdvideoguy/cycle/Welcome.html http://greencarvideos.blogspot.com/

48/56V generator and science-fair wind | 12 comments (12 topical)

Re: 48/56V generator and science-fair wind (3.00 / 0) (#1) by Electron Pump on Fri May 08, 2009 at 03:18:28 PM MST

I dont know how to advise you but your idea sounds good. I'll bet you can make it work. I'm going to follow this post.   I've been following the government incentives for electric vehicles and hope to owne one someday. Electron Pump

Re: 48/56V generator and science-fair wind (3.00 / 0) (#2) by willib on Fri May 08, 2009 at 07:25:53 PM MST

What i would do , when i have a go at an eBike is to use the original trans ,and hook the motor to the original crank ,with a chain. Think of it , going through the gears with an electric motor would be so cool. Might improve the mileage a bit also. Carpe Ventum (seize the wind) One needs faith in the future

Re: 48/56V generator and science-fair wind (3.00 / 0) (#3) by wooferhound on Sat May 09, 2009 at 04:47:59 AM MST

I'm thinking that you need to ditch the idea of a trailer because it will add so much unnecessary weight. I would mount a weedeater motor on there with a generator attached to it. It's not much more than a trickle charger, but then you can charge the batteries anytime you want too. And you will get some interesting looks from folks wondering how your Motorcycle runs off of a weedeater motor. W o o f -={(

Re: 48/56V generator and science-fair wind (3.00 / 0) (#6) by mikeyny on Tue May 12, 2009 at 05:49:07 AM MST

I guess you could use a generator kind of like the ones you put on a bike tire to lite a lamp and trickle charge. simple enough and wont take to much to run it. 2 may get more charging ability. I suppose you could always scale down an other power genny set up for low speed charging and atach it to the wheel. But the weedeater set up woof mentions would be independent and take nothing away from performance. Just another thought.                                                        Mike "I thought I made a mistake but I was wrong" [ Parent ]

Re: 48/56V generator and science-fair wind (3.00 / 0) (#4) by dnix71 on Sat May 09, 2009 at 11:49:34 AM MST

Instead of a trailer, maybe get a detachable sidecar for longer trips. The facilities manager at work has a Harley set up like that. The drawback to electric vehicles where I live (south Florida) is top speed. Anything that can't go at least 50 mph all the way home will get run over from behind. There just aren't any city streets that go long distances. I have an electric bicycle. Here, as long as you aren't a jerk, no one cares if you use the sidewalk. Few people walk anywhere anyway.

Re: 48/56V generator and science-fair wind (3.00 / 0) (#5) by huntedheads on Sat May 09, 2009 at 01:56:14 PM MST

Yes it's possible! I just looked at one a month ago but don't remember the site name. It was about electric cars and it had a yellow roadster on the front page and when he needed to drive farther to a car show he hooked up the matching yellow roadster trailer equipped with a propane powered generator. Sorry I cant be more help but if a car can do it a motorcycle should too. Keep looking. [ Parent ]

Re: 48/56V generator and science-fair wind (3.00 / 0) (#7) by Bruce S on Wed May 13, 2009 at 11:13:29 AM MST

Ben;   There are a few ways you can go about doing this. Would like to get just a little more info if okay. How are you currently recharging them? AC charger made specifcally for the setup? It seems if you are able to build such an animal, you probably already have the skills to build a charger, but need to ask: How are your circuit building abilities? A quick and dirty way is to go find/buy/repurpose (4) 12Vdc small style chargers and hook them up to each battery, and using the idea put forth by Woof. Most of these units are step down chargers that will step down the 110Vac to ~14VAc then rectify them out for DC. Unless you are going on long distance trips 50+ miles, the trailer will probably not be the best idea. IF you want, you could move the large batteries to a trailer with the charger constantly running to charge these, with minimal batteries on-board to lighten the bike, but then you are limiting yourself again. Do you have picks of the bike and it's layout? Will help to see how much working room you have for a solution. Keep Smiling; Bruce S

Re: 48/56V generator and science-fair wind (3.00 / 0) (#9) by ghurd on Wed May 13, 2009 at 11:41:18 AM MST

"AC charger" made me wonder. Guessing the grid charger is 100~500W?  Or should be simple enough to buy/build one around that size. Little B&S mower engine, cheap 35A GM alternator, small (85AH?) 12V battery, 400~750W inverter, then the AC charger. It could keep charging at red lights, getting a cup of coffee, getting rid of the last cup of coffee... Certainly not a great idea, but maybe it would be some proof of concept. Easy enough to try without a whole lot of money, and all the parts would still be usable if it didn't work out. G- Ghurd.info [ Parent ]

Re: 48/56V generator and science-fair wind (3.00 / 0) (#10) by Bruce S on Wed May 13, 2009 at 01:34:29 PM MST

G- You caught the question for the charger right on the nose :0). Thanks for expanding on the thought and build. Our e-scooter gets this kind of charge once in a while, just to make sure all is well. Using Vector 750watt 12V, and original 48V 18Ahr SLA rated charger. Also thought MAYBE couple of your dump controllers would work using 14.4 as set voltage with of course higher incoming voltage. 4 of these set for each individual batt, could be a very nice way to go, but I would be a little worried about needed charging current along with the rest of the system's isolation. Thoughts? Trying to get you up to multiple dozenaire :) Bruce S [ Parent ]

Re: 48/56V generator and science-fair wind (3.00 / 0) (#11) by ghurd on Wed May 13, 2009 at 03:31:12 PM MST

The high voltage work-around is doable.  Pretty sure there is one running on a 48V regenerative braking system.  Can't recall the project specifics. Isolation is not a problem either. Current is not a problem, with a small pile of cash. Not sure I like the idea of dumping very much power derived from GASOLINE! Maybe it would help keep the batteries more in line with 4 controllers... meaning it would need 4 controllers.  I feel the bakers dozen dollar on it way.  LOL. G- Ghurd.info [ Parent ]

Re: 48/56V generator and science-fair wind (3.00 / 0) (#12) by Bruce S on Wed May 13, 2009 at 04:09:37 PM MST

G- 4 controllers would be the way I would go. Let the individual batteries take the charge they need; rather than bulk it out. Would keep parts, heat, FETs count and costs down. Would be too good for larger sets due to costs, but .... True true true: I don't like dumping dino power either.   [ Parent ]

Re: 48/56V generator and science-fair wind (3.00 / 0) (#8) by Bruce S on Wed May 13, 2009 at 11:21:29 AM MST

Ben; Have had a little more time to re-read your request. What is the rating and model of the motor you are using? How fast are you normally going that gets only 30 - 20 miles round trip? Also, the newer alternators "can" be altered to out put higher voltages just like the older ones and are tons of websites just for this. On here there is a post about building the 4hp genset. I think it has a link that is very good for ideas. Keep Smiling; Bruce S

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