any ideas how to add generator to 142f ghost racer

X

xlander

New Member
Okay so I've got my bike running nice and holding together. Anyone have parts/ plans to add a generator to the engine that could drive 2 cree t6 led lamps. It would be nice to stop worrying about charging and carrying rc batteries... since the Cree stock batteries are junk.
 
The 49cc HS 142F engine you have does not have a power mag, but I'll bet you could attach one right next to the spark mag.

Slugo3right.jpg


Don't mind the kill button wire wrapped around the pull start, I just wanted the wire out of the way ;-}

A ~12V mag to a 7.2VDC converter and you could tie it right to your battery.
Those CREEs suck a lot of power, especially the multi-lamp ones.
 
That exactly what I was asking. Does anyone have the parts for a power magneto that could mount to the side.

The Cree single lights also pull a lot of juice and you can't trust the low power indicators built into the switch. It only warns you when you have already past the safe area of a lithium battery.
With a 5200 mah battery I get about an hour. I ride out of the city where there aren't street lamps so bright lights are necessary. Again that is based on knowing what the safe low draw of the battery is. For me that means not going lower than 3.9v lowest 3.8v per cell. I know they say you can go lower but a full draw is way harder on the batteries life than a partial draw.
 
It bolts on under the air filter , there's 3 mounting lugs that work perfectly! That is a 12V magneto and I use it to run the head light and tail light. The battery is a 9V Lithium Shorai that runs a horn and a insanely bright yellow flasher on the back of the bike.
 

Attachments

  • image.jpg
    image.jpg
    434.2 KB · Views: 471
Msiert said:
It bolts on under the air filter , there's 3 mounting lugs that work perfectly! That is a 12V magneto and I use it to run the head light and tail light. The battery is a 9V Lithium Shorai that runs a horn and a insanely bright yellow flasher on the back of the bike.
Click to expand...


do you have the battery running separately from the 12 volt headlight system?
It's good if it runs a headlight and tail light. I may just get one of those.
Curious though, can you use a twelve volt battery with it? or won't it help keep up the battery?
 
trialnerror said:
do you have the battery running separately from the 12 volt headlight system?

It's good if it runs a headlight and tail light. I may just get one of those.
Curious though, can you use a twelve volt battery with it? or won't it help keep up the battery?
Click to expand...

The battery is not running the head and tail lights, the 12V magneto is. The real purpose for the battery is to supply the amps to honk the horn.

Don't know if the magneto could be used as a charging system for the battery, but I doubt it. The Lithium battery takes a special (Shorai) charger to charge it and maintain it.

One thing to keep in mind is the PB (Phantom Bike) head lights are LED and I have rode at night with them, they do provide just enough light to see right in front of you but not much at a distance. I wouldn't trust them to light up a pot hole at 20yds.

I have thought about getting another Harbor Freight "Off Road Light" and use it's 55W light bulb and tie that into the battery for night riding but I never ride at night.

The PB LED headlight is a very bright pulsating light (it has 12 LED's) and works well to alert driver's your coming towards them night or day and I think it does a better job durning the day over a 55w light runned by the battery so I'm staying with the 12v LED headlight for now.
 
An external bolt on mag, clever and easy but not really efficient, for max efficiency you want the coil as close to the spinning magnets as you can get with nothing in the way like an engine cover.

There are plenty of uses for that mag, you just need some basic electrical skills to pull it off is all.
 
Last edited:
Here a pic of the mag with the engine cover off. The cover is cut out around the mag.
 

Attachments

  • image.jpg
    image.jpg
    289.9 KB · Views: 458
Msiert said:
Here a pic of the mag with the engine cover off. The cover is cut out around the mag.
Click to expand...

So it is essentially the same as the one abikerider made a few years ago, just upgraded and perhaps some diodes to make the output DC, ( 4 - sixty cent diodes for full wave rectification). which can easily fit in the housing shown.
It should be able then to power the Led headlight I have , which I can see very well for about a hundred feet on the darkest night just off a 12 volt 1.3 amphour emergency light battery, that I have been using as of late.

http://motorbicycling.com/attachment.php?attachmentid=20117&d=1265647134 ----this picture is from abikeriders post a few years ago. I hope he doesn't mind me referring to it?
 
Last edited:
Msiert said:
Here a pic of the mag with the engine cover off. The cover is cut out around the mag.
Click to expand...
Nice, thanks for the pic, that has a set of big coils and yes, judging by the housing plenty of room for a full wave in there.
 
it could most likely be easy to even add a regulator with a couple resistors and a zener diode as well, or one of those ready made rectifier/regulators for a scooter.??

Hmmm

I wonder what the actual output is and wattage?
 
trialnerror said:
it could most likely be easy to even add a regulator with a couple resistors and a zener diode as well, or one of those ready made rectifier/regulators for a scooter.??

I wonder what the actual output is and wattage?
Click to expand...
The AC output will vary by RPM.
The faster it spins the more power it creates.

The more you draw directly, the more engine resistance it will cause, that's why a battery is such a good buffer, the engine doesn't have to work too hard to 'trickle charge' a battery but no matter how you do it, there will be an equal loss in the available engine power to put to your back wheel.
 
KCvale said:
The AC output will vary by RPM.
The faster it spins the more power it creates.

The more you draw directly, the more engine resistance it will cause, that's why a battery is such a good buffer, the engine doesn't have to work too hard to 'trickle charge' a battery but no matter how you do it, there will be an equal loss in the available engine power to put to your back wheel.
Click to expand...

This little engine only spins so fast.
An actual answer with numbers, would have been good. Question, better stated as-- how many AC volts would it be ""capable of"" at riding rpm?--like maybe 20-22 so when rectified it would supply at least 14 volts DC---
I really would not care if at Idle it made only 6 or 7 volts AC. The battery would supply the lights for those few moments.
I believe the loss in engine power would be so insignificant that it would not matter. after all the only thing it's doing is using the magnetic flux field so there is No physical friction involved. And those magnets aren't strong enough to create that much drag on the engine where you would notice, or else the ignition coil would make so much drag, there were be no engine power, right?
 
trialnerror said:
I believe the loss in engine power would be so insignificant that it would not matter.
after all the only thing it's doing is using the magnetic flux field so there is No physical friction involved.
And those magnets aren't strong enough to create that much drag on the engine where you would notice,
or else the ignition coil would make so much drag, there were be no engine power, right?
Click to expand...

Nope.
There is no such thing as free power.

Big generators require a huge amount of force to make power, that's why they put generators at the bottom of reservoir damns, to use the weight of the water to spin the magnets.

This a 49cc engine, big enough to power a little mag under minimal draw, but if you are riding at night trying to run like 5 Amps for light you WILL feel it in performance and how often you have to gas it up.

Again, no power is free, but just drawing a little at time all the time with a buffer like a battery to save it, the effect should be minimal.
 
well then mine should be OK cause the headlight and two taillights only draw 480mA from a 12 volt dc battery supplying 1.3 aH. Besides I don't need megawatts to be generated. I know power is not free, the engine does use gasoline. and the magnets on the flywheel, passing by the coils doesn't use that much energy that it would be even be noticeable. insignificant power loss. those tiny Honda generators can handle over a thousand watts, so this little motor won't even notice 7 or 8 amps. besides it doesn't have to spin a big heavy armature between big strong magnets , just the flywheel with weak magnets and clutch.(a lot less in friction as well with less bearings involved) alas, still no numbers, just another lesson in electrical power generation.

I still wonder what the actual AC voltage output is at any given rpm and amperage under load ? pick a number like 2000 rpm? maybe I am asking too much for a couple numbers, and need more lessons instead? I would like to know before spending a few hundred bucks and the time to build a laminated core and testing several windings or just spend the 200 bucks and get that prewound coil from PB. rectifying and regulating is the easy part.
 
Last edited:
You need to know the gage of the coil wire and the number of windings.
Then just google for the formula to do the math.
 
You must log in or register to reply here.
Back
Top