"Perpetual motion" truck

i agree with what few have said. good for him. it looks like something i would have tried to build when i was 12.. but i'm a nerd... and i looked into true concepts of perpetual motion at that age and even have a design of my own... top secret still.. sorry.



basically he's wasting a lot of electricity.. so yeah.. pull the extra crop of their and he'll save a large percentage of energy for running that truck. as a large truck, he can fill the entire chassis with those batteries. it's an idea i 've had for big rigs. line the trailor tops with solar panels, and line the chassis with batteries. they charge all day, and would help propel the truck on clean electricity. maybe this guy has a potential start for something a lot bigger... *shrug*



Now.. if he were to have at least one friend off here to help him.. instead of beating him up (dissapointed in you guys).. then he would have an awesome little project on his hands. something worth more than just scrap.

 

<div class='quotetop'>QUOTE(IAO @ Oct 18 2007, 01:26 PM) [snapback]527389[/snapback]</div>

Actually, I think you would have to run the test on only 5 fully charged batteries. The test would be to see if 5 fully charged batteries with no drag (alternators) would have a further range than the current set-up of 5 fully charged batteries with drag (alternators) recouping lost energy into an empty bank of 5 batteries, and then reappying that lost energy to drive the truck further, and so on. To make the test fair, you would have to make sure the vehicle weights are the same. It would be simple to do in his set-up... just charge up one bank and leave the other bank disconnected (along with the extra drag) for the first part of the test.

 

<div class='quotetop'>QUOTE(IAO @ Oct 18 2007, 01:26 PM) [snapback]527389[/snapback]</div>

I think the point is that he would be better off just hooking all 10 batteries to the motor. The amount of energy generated by the second MG is by definition less than the amount of battery power needed to drive the load of the second MG. As efficiency approached 100% they would be equal. Given realistic charging efficiency, belt drive efficiency, friction effects etc I think he would be doing very well to get 60-70% efficiency. This would mean that however far he could have gone with all 10 batteries, he'll optimistically loose about 30-40% range with this arrangement. The only good thing about his setup, is he should get regen adding maybe 5-10% range back. However, this is due to running the two motors not splitting the battery pack. If he had all 10 batteries in one pack and engaged the second motor only under breaking he could probably get 105-110% of his straight 10 battery range.

here is an example of a similar truck:
http://www.austinev.org/evalbum/861

This one uses 20, 6V 232Ah batteries for a 27.84kWh nominal pack. He claims a 55mph top speed, and 40+ mile range which is very plausible for a vehicle of this configuration. The batteries in the article look like 12V, ~100 Ah. So for all 10 he would have about a 12kWh nominal pack. So our friend in the article should get about a 17 mile range with all 10 batteries and no MG2. In his current arrangement he would be doing well to get 10-12 miles. The top speed claim is a bit dubious. Generally the smaller the motor the more voltage you need to get the required torque out of it at a given rpm. Given that his alternators appear large for alternators, but much smaller than the 9" forklift motor used in the reference truck he would need much higher voltage to get similar top speed. In fact the reference truck has a 120V (6x120) system, our friend in the article has a 60V nominal (5x12) system. If he tied all 10 batteries together, he could have 120V, and depending on how strong his alternators are _could_ get up around 50mph but I doubt it.

I think its great that he is playing around with electric cars! We need this to become perceived as a common fun hobby (like other automotive hobbies) in order to help drive demand for BEVs. Much the way the PHEV hobbyists are driving demand for commercial PHEVs. It think this was the local physicists point, rather than commenting on the specific merits of this design. If Bubba (forgive the regional/cultural stereotype) decides its cool to build an electric car, we will well on our way down a better path. If there is a potential downside, its the clueless newscaster getting over excited about a poor design and then people being disappointed in its capabilities down the line. This could add to the negative perception of electric vehicles. In the mean time its a shame these people aren't aware of the really great projects going on in the EV world, like White Zombie, Kilacycle, tesla motors etc.

Rob

<div class='quotetop'>QUOTE(V8Cobrakid @ Oct 18 2007, 01:40 PM) [snapback]527393[/snapback]</div>

Hee hee, me too! I drew my first "fuel cell" powered vehicle when I was about 8, the day I learned about electroysis. Tank of water, use electricity from battery to break into H and O2, burn H and O2 to power vehicle, recharge battery, and replenish the water tank ad infinitum. Global energy crisis averted. That wasn't so hard! :lol:

Was very annoyed when I learned about perpetual motion later :angry:

rob

 

Okay, so now time for a reality check.
If someone else came up with an 'independent' thought on how to build a hybrid mechanism, think of the licensing hassles that could be avoided whilst selling it to, say, some car company that DIDN'T have patents on some sort of Synergistic Drive...

 

Here's a thought. Instead of using 2 banks of 5 batteries each, let's use a small 1.5L engine on the one side, and then recoup the losses with the batteries on the other side. Then we can use that recouped energy to further the range. At the very least, we'll squeeze more miles out of the 1.5L engine in our hybrid setup versus just running the engine alone. Oh wait... that's already been done, and it's called a Prius.

Some of us are better at recouping our losses than others... witness some folks here getting 60-70mpg vs. others only achieving 35-45mpg.

The bottomline is that guy gets infinitely more miles to the gallon than anyone here, because he doesn't use any gas, and that's the point anyway, isn't it? I say, more power to him and good for the EV movement to have the news give attention to it. And as the previous poster said, to get backyard mechanics tinkering and thinking about clean energy, instead of installing headers, turbochargers and what not.

 

<div class='quotetop'>QUOTE(PriuStorm @ Oct 18 2007, 04:25 PM) [snapback]527465[/snapback]</div>

Sure, we all understand that he hasn't created an energy free vehicle. As it is driven it will use up the energy stored in the batteries. No matter how many times he manages to pass energy back and forth between the 2 battery banks, eventually there won't be enough left to propel the vehicle.

Ok, so the main question I have that I haven't seen answered is, how does he get the battery bank charged up to start with?

If he has a plug in charger, then he has created a functional (though rather inefficient) EV. Great!