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Can you use an alternator on an axle to recharge batteries? Answered

If you have a battery powered vehicle of some sort, can you put an alternator/generator or something on the axles to generate electricity to recharge the batteries the vehicle runs on? When the axle turns, the brushes pass over the coil generating electricity which is then routed back to the batteries thereby recharging the batteries. Please pardon the bad Paint drawing, but something like this.

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CharlesA132
CharlesA132

11 months ago

Why can't you put permanent magnets in the wheel (balanced ofcourse) and place your stator around or behind the brake rotor? Without a housing you wouldn't be adding a ton of weight and the stator shouldn't have to be much bigger than the top 1/3 or less of the rotor.

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 Chittermlitem
Chittermlitem

4 years ago

keep an open mind here, we do not need reminding of perpetual motion machines just finding advantages to extend the distance an electric vehicle can travel. To make a system more efficient is the basis behind any engineering project. With regards to the idea to design a alternative charging system using a alternator(s) or generator(s) to supplement the energy required for the batteries to have an extended run time using the axle as a supplier of energy is possible.

A lot of energy is lost to put a vehicle into motion. Picture this drivetrain for example...you pull the engine of your existing vehicle and couple an electric motor with the same horsepower as the engine had. Replace the exhaust, fuel, cooling, air and computer systems with a power pack and controller. The weight difference is negligible. Forget about how far you can travel on petrol compared to stored energy for a moment.

Briefly, the power losses from the electric motor (electric motor losses) through the gears in the transmission/transaxle (friction/mechanical are the same as with an engine) through the axles (more friction and heat) to rotate the wheels are all losses. Nothing in this scenario has changed from the petrol powered system except the electric motor is more efficient than the ICE.

To rotate the tires in this drivetrain system the power is transferred from the electric motor to the wheels with some percentage of power losses.

Who cares

There is a mechanical advantage acquired through the transmission/transaxle/rear end gearing to bring the vehicle to highway speeds.

Once you reach a steady velocity your object is now in motion.

Now is the optimal time to engage your alternator(s)/generator(s). Attach your alternator/generator (secondary) pulley to the inside of your vehicle wheels(rims) (primary pulley)

Basically run your generation system off the inside of your wheels(rims). If your vehicle wheels radius are 6 inches, your vehicle is moving at 100 km/hr you can expect the wheels are rotating at 1740 RPM. If your generator pulley has a radius of 1 inch you do the math 6:1 ratio. You can expect an arsenal of available energy and momentum to harness. The type, size and material of the pulley you use here on the alternator/generator is critical, you have to find the ideal fit between force (possibly movable force; an alternator that can move electrically or mechanically by hand levers, maybe mechanically using vehicle weight distribution or hydraulic brake pressure like a clutch slave cylinder and lever) against the wheel(rim) versus friction for your application.

There will be some losses from the alternator. Essentially this could also act similar to regenerative braking by increasing the magnetic field in the generating system. More pressure would also be required between pulleys (vehicle wheel and generating pulley) to prevent slipping between pulleys. There is a factor of motion down a hill to also consider, in hilly areas you could use gravity to aid you in your mileage increasing your rotor/stator field strength to your generating system going down hills. A more sophisticated system could auto detect these hills and hard braking.

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gary0116
gary0116

5 years ago

You might think about building your own solar panel for the roof. Much less work and the return is greater. This something I'm currently working on. Plus I would like to be able to use the 150 dollar deep cell battery from any auto or marine place. There are many different batteries. There are benefits and pitfalls to each.

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avocadostains
avocadostains

6 years ago

The thing about drive alternators is you have to overcome the resistance of the alternators rotor. But if the car axle itself were the rotor and you were charging capacitors or using a diode to charge batteries, there would be no backfeed, no 'load'. To me this idea makes perfect sense, although I really have no idea/experience/knowledge to back that up.

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peter.christie.73
peter.christie.73

Answer 6 years ago

AN
ELECRIC CAR

The time has passed for an electric car. A car one may never have to plug in. The production of oil is all coming to a
close and gas and oil companies are spending 165 billion on exploration and
what are they going to do to our oceans that are in danger of dying
already. The price of oil may rise to
$200 a barrel or about $8 or $9 a gallon for gas or more and that is if the tax
on gas doesn’t go up. When solar panels
became popular to me in 1979 I was thinking of a car with solar panels on the
roof, trunk lid, and hood, then possibly on the tops of the fenders.

Over time we now have the greater black solar that
acquires power faster so we make a car like above and then add two freewheels
that will spin maybe a bank of hi-output alternators, then air-scoops turning
other hi-output smaller alternators. And if not too much drag hi-output
alternators working off the other wheels or axels, and if one just went to work
and back home one may never need to charge the batteries which would cost how much
on the electric bill??? We could call
it The Free Ride, and get permission and play Edgar Winters, Everybody Take A Free ride in
all new FreeRide.

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avocadostains
avocadostains

Answer 6 years ago

i bought 2 of these little toy ysolar cars. These suckers GO! no batteries. Just a small gear on the shaft that drives a slightly larger gear on one side of the axle. http://www.ebay.com/itm/New-Wholesale-Kids-Adult-Solar-Power-Mini-Toy-Car-Racer-Educational-Gadget-Hot-/141363204837?pt=Baby_Toys&hash=item20e9e752e5 I'm thinking a scaled up version??? Why not?

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avocadostains
avocadostains

Answer 6 years ago

Even if the resistance of the rotor isn't much, you also lose energy transferring power with a belt.

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avocadostains
avocadostains

Answer 6 years ago

Unless the magnetic fields in the generator itself are working against the turning of the axle. Not sure how that works.

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jeanga1
jeanga1

8 years ago

how about TWO batteries???... one used for the vehicle and its uses..

the alternator charging the unused battery.. then when you need power swap over to the charged battery then vice versa.. would that work ??/

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jeanga1
jeanga1

Answer 8 years ago

I mean like a dynamo affect.. charging the not in use battery when your on the go instead of having to plug in to charge, or using a trickle feed solar panel to charge your unused battery while using the other fully charged one to power

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Andale_The_Great
Andale_The_Great

9 years ago

I actually asked this question once and tried to build a little go-kart to test but had to much trouble getting a motor that would work for it.
I think that with proper gear ratios you could get a much larger return by using an alternator that is built for much heavier duty rather than a little <150 watt car alternator.
I once used one with bicycle gears to make the ratio changes and had it powering a light, but only as an experiment, it wasn't practical and the low speeds produced little amperage. The amount of extra bits made it unusable as a bike also.

Another thing to remember is that in most instances your alternator actually requires some electricity to run too. Something to do with creating the EM field inside it. So your not just losing on the mechanical side.

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Zippomanonfire
Zippomanonfire

11 years ago

With this possible concept and with the regenerative braking concept, other than normal battery life expectancies and overuse etc., what would keep it from going 1000 miles on a charge if it is constantly recharging? Unfortunately Electronics isn't my thing. I don't get why if it recharges itself, you only get like 20-80 miles per charge. Lemonie- this might go a little into the perpetual energy thing.

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ANDY!
ANDY!

Answer 11 years ago

You better watch out. You need voltage regulators and stuff but you can get speed controllers to do that.

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jtobako
jtobako

Answer 11 years ago

A little? You think? Try this. Take a alternator or dc motor and spin it by hand. Eventually it stops, right? That's friction losses inside the alternator. Now connect the output together so it's shorted out and try to spin it again. Little tougher, huh? That's because the physical motion is being converted into electrical work (in this case heating up the wire that's shorting it out). Every bit of friction and work and conversion to heat saps energy. By forcing the motor to run an alternator you loose energy (about 20% plus friction to get the power transferred). By adding the alternators you get LESS range because of these losses.

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lemonie
lemonie

11 years ago

Yes, but please tell us this isn't some kind of "free energy" idea?

L

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Zippomanonfire
Zippomanonfire

Answer 11 years ago

Nope, Just don't want to have to plug it in all the time/possibly extend the range.

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frollard
frollard

Answer 11 years ago

so you're thinking have a motor drive you foward, and alternators generate power for you.

Only problem with that concept is that driving forward *costs* energy from the batteries, in exchange for motion.
The alternators *cost* energy from the momentum, slowing you down 'equally' - so you dont just get to keep the momentum AND the energy into the battery. When you use your alternator concept, the car comes back to a halt.

This is effective for recouping energy instead of putting it into heat in the brakes. - hence 'regenerative braking'

One time I hooked a small dc motor from a toy to a small dc generator, and it was pretty neat. Normally the motor would stop quickly, but this device would slow down much less quickly (would run for 2-3 seconds instead of less than half a second). This did not mean I was getting energy for free, just that it was recouping some.

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lemonie
lemonie

Answer 11 years ago

You can use the motors to regenerate the batteries on downhills, some simple switching. L

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Zippomanonfire
Zippomanonfire

Answer 11 years ago

Would it be just as simple as fabricating something like my above design? Or something more involved?