Series Hybrid Weed Eater Powered WE BD48

[AussieJester]

Probably the best type of generator would be a 3 phase generator which is easier to rectify to dc. This would be like a car alternator. I don't know if they are available in the 1500W to 2000W range. I would suspect that is what is used in hybrid powerplants. I wonder if I could rewind or modify a car alternator to get 60VDC. I could make that work with my hubmotor.

I have been looking into building a few wind generators for my workshop/living area and came across alot of plans for them on the net several use the Fisher & Paykel Washing machine motor for the generator after rewiring it Don't know if this is of any use to you they might be too larger (physically) for the application at hand but i thought i would make mention of it in case... best of luck with the venture will follow with much interest

Kim

 

[Jeremy Harris]

Probably the easiest/lightest three phase generator would be a brushless outrunner RC type motor. These have a very low winding resistance so will deliver a fairly high current with low losses. The only snag is that they need to be turned at high speed to get high voltages out.

Take a look at this, for example: http://www.hobbycity.com/hobbycity/...werPro5330-10T_679g/215kv/80A_Brushless_Motor

It's rated at 2800 watts, so should be fine for a decent size alternator. To get around 50V from it you need to drive it at about 11,000 rpm though, which may be tricky in terms of drive components. The weight's pretty good though, just 679g (about 1 1/2 lbs).

Jeremy

 

[E=IR]

Those are some amazing motors.

One problem with going to a car type alternator is that it cannot be used as a motor to start the gas motor (I think this is correct).

I will have to look at those RC motors, the power output is right and the price is right. The rpms are a challenge but with a geared system might be possible. Its amazing how much power can be produced out of those things.

 

[E=IR]

This looks promising:

http://www.windbluepower.com/Wind_Blue_Motor_Hydro_Permanent_Magnet_Alternator_p/dc-500.htm

http://www.honda-engines.com/engines/gxh50.htm#per

A little bit higher rpms than I would like, but under load, bike operating voltage is typically in the upper 40's, with target voltage (fast charge voltage) of 58V. It should work running at just over 5000 rpm. The gas motor is the limiting factor, with output of 1.5kW compared to the rated (50V x 125A !?!? =) 6.25kW of the generator. Methinks the generator would be letting out some magic smoke at that power output. Since the bike motor is rated at 600W, this should be ample power.

 

[E=IR]

It seems the chart is wrong and it should produce a maximum of somewhere between 20 and 50 amps.

20 amps at 50V would work fine for my bike at 1000W.

 

[E=IR]

Hmm, will not work as a dc motor to start the gas motor.

 

[trappermike]

E=IR...
Ingenuity!!
But as a motorcycle,small engine mechanic I can say one thing....I hope you put the original plastic housing "Fan shroud duct"!
If it is not on like your photos,the flywheel fan will not be able to blow cool air over the cylinder and I'm sure it will sieze before 20 minutes,it's Fan -cooled.Luckily there is tons of these cute little guys in yard sales,the carb was their only weak point,but this easily remedied for almost nothing.
Make sure to incorporate this in your design and I think it will be great.!!
I'm an engine nut,I had 2 of those motors that I ported,put big carbs on etc.,even my lawnmower isn't stock...

 

[paultrafalgar]

I expect you've all seen this, but for those who haven't:
http://www.youtube.com/watch?gl=GB&hl=en-GB&v=PJDNWcnYlFo

 

[kazbluesky]

I just found this thread. Excellent Thread. Really interesting. I like paultrafalgar's post too. The idea of running a small car/trike-type-thingy off batteries with a top up from a little Honda generator (which can be ported to the house or garage when needed) is something I wanted to work on when I finally settledown in NZ in the next year or so. I intend to go very green with my house,transport/lifestyle when I get there. It's exciting to me to see the same kind of thing done on a trike - kind of inspires me. Thanks very much.

 

[Mr. Mik]

Sorry if I'm the only one here who does not get it....- but how is this supposed to work?

Do you crank up the noisy weedeater motor each time you come home, instead of using a DC-grid supplied charger for the batteries?

Or are you going to pull it behind on a trailer?

Or am I too stupid to get it?

Puzzled....

 

[Toshi]

Sorry if I'm the only one here who does not get it....- but how is this supposed to work?

Do you crank up the noisy weedeater motor each time you come home, instead of using a DC-grid supplied charger for the batteries?

Or are you going to pull it behind on a trailer?

Or am I too stupid to get it?

Puzzled....

you run it as you're riding the bike. it supplies power through the DC motor acting as a generator, thus lowering (but not zeroing) the draw off of the bike's lead acid batteries.

props to the OP for making it work. as a proof of concept it's very interesting.

 

[D-Man]

Any more progress on this?

 

[seanreit]

Ya, anymore progress?

 

[Toboldlygo]

I put a 4 cycle string trimmer engine onto a 100 watt 24volt DC brushed motor, which easily revs (guessing 2500rpm) to 30 volts. I'm planning to regulate this voltage to about 28 in order to charge a Lithium pack ( max safe charge current 6 amps). Any suggestions on how to govern the revs? As soon as I put a load of 3 amps it slows drastically. I read these engines should push about 1hp, so about 700watts, so I should easily get my150 watt target.
I'm planning to mount the assembly to an ebike that with pedaling draws 350 watts from a stop, and 100 on flat road.