add an alternator to a standard kart?

[supermanotorious]

I tried searching for this possibility and wonder if this is it:

http://www.diygokarts.com/vb/showthread.php?t=451

What I would like to do on my 2002 Yerf Dog is keep a 12V battery on board to run lights and such. I want to use the axle as a jackshaft as well to run an alternator which will keep the battery charged. I know I would need a charge controller. Has anyone done this? What alternator did you use? Where did you find the pulley for the axle side? Here's what I have in mind, Engine Battery Alternator Tire

 

[devino246]

It wont work

First, alternators consume a surprising amount of horsepower. Adding an alternator to you kart in any way will kill your fun.

Second, alternators dont work very well at the low rpm that your axle is moving. Consider this: Most cars idle around 500-800 rpm. Assuming your kart is geared at 6:1, your axle is turning at 600 rpm, but thats at full throttle. You likely wont spend enough time in the upper rpm range for your alternator to charge your battery.

 

[supermanotorious]

thank you for explaining that, so I will add the battery and install the Harbor Freight solar panel and charge controller then, since I live in Phoenix, AZ I should be at a full charge 360 days a year! Has anyone added a tachometer to their small kart engine?

 

[devino246]

Keep in mind, that solar panel only produces 1.25amps, only enough for a trickle charge. What do you need the power for?

Several members have used the tiny tac.

 

[bighead]

mini windmill generator. Check it out?

 

[supermanotorious]

I want to install running lights and maybe a stereo since this is a large Yerf Dog kart and space is not too limited, I am a professional car audio installer and I don't anticipate the accessories will drain the 12V battery in a day, also for Christmas day I was thinking of putting one of my inverters on it and wrapping it in Christmas lights for the kid

 

[fowler]

u could just buy a wall charger and plug it in after every ride
or after every use of the battery

 

[supermanotorious]

good point, I do have a nice charger already but I thought of the solar panel as "maintenance free" plus it will provide a little bit of shade for the riders and I'd be soooo green lol

 

[used2jeep]

If a non electric kart cannot have a generator/alternator then how do the electric start karts do it with their battery?

 

[devino246]

If a non electric kart cannot have a generator/alternator then how do the electric start karts do it with their battery?

They usually have a small charge coil built into the engine.

 

[r_chez_08]

Could a small 12v dc motor not be used as an alternator? Possibly have it running like a chain tensioner off the drive chain?
http://www.motiondynamics.com.au/st...s-en/dc-12v-100w-2750-rpm-electric-motor.html

 

[devino246]

Could a small 12v dc motor not be used as an alternator? Possibly have it running like a chain tensioner off the drive chain?
http://www.motiondynamics.com.au/st...s-en/dc-12v-100w-2750-rpm-electric-motor.html

I posed that question a while ago: http://www.diygokarts.com/vb/showthread.php?t=7649&highlight=electric+motor

...a 24V 8A @2600rpm motor. At 2340rpm, it produced 20.4V. At 3100 it produced 27V...

Only problem is that you wont get consistent voltage, although you could find a voltage regulator off an old car that still used a generator.

 

[crazzywolfie]

if the kart is gas powered i don't see why you couldn't. you could probably put it on a toggle switch so that it does waste any power when not needed and maybe you could install a brake switch so that when you hit the brakes it turns the alternator on. just an idea. it is kind of like drag race cars. there is usual an alternator under the hood but it is off when they are taking it down the strip but on when they are waiting around or moving it.

 

[devino246]

if the kart is gas powered i don't see why you couldn't. you could probably put it on a toggle switch so that it does waste any power when not needed and maybe you could install a brake switch so that when you hit the brakes it turns the alternator on. just an idea. it is kind of like drag race cars. there is usual an alternator under the hood but it is off when they are taking it down the strip but on when they are waiting around or moving it.

If the alternator isn't hooked up, whats powering the ignition system and gauges?

Even if the alternator isn't supplying power, it's still robbing horsepower.

 

[crazzywolfie]

when the alternator is turned off the battery is there to run the ignition system and gauges. if the alternator is off then i doubt it would rob much if any power. it would almost be like running an idle pulley.

 

[kendelrk]

me and my neighbor but this idea together, running a direct drive sprocket to a jackshaft, on that jackshaft there will something that can generate power (alternate of some sort) and on the other side would be a clutch running to the sprocket, this way the alternator is always running and making power, but then you also dont engage till you would with a regular clutch

 

[supermanotorious]

has anyone had success with a bicycle dynamo generator? I've got my eye on THIS one but would like to know your thoughts before buying, also think you can pair it with THIS for charging the battery? I think it would work after looking at specs on both, I would probably use relays on the lights so they get 12V direct from the battery, switched on by 12V lead from controller output

 

[crazzywolfie]

i don't think that would be powerful enough to charge a battery. it is only 0.5 amps plus i think it is also AC so i don't think you could charge a battery without a diode bridge and a diode bridge would cause a voltage drop.

 

[supermanotorious]

i don't think that would be powerful enough to charge a battery. it is only 0.5 amps plus i think it is also AC so i don't think you could charge a battery without a diode bridge and a diode bridge would cause a voltage drop.

I dont know where you got 0.5 amps charge rate, this is for a dc system, the solar panel it was designed for is 12v, even if it is 0.5 amp wouldnt it trickle charge? keep in mind this is mainly to power headlights, I'm looking at several options and by my calculations the battery should store enough juice to power one night session of driving, potentially up to 10 hours, I'd probably use the solar panel as well so the battery gets charged even while idle

 

[devino246]

I dont know where you got 0.5 amps charge rate, this is for a dc system, the solar panel it was designed for is 12v

That dynamo generator outputs 6w @ 12v. VxA=W, so 6/12=.5amps