Alternator v. no alternator - 10% gain @ 70 km/h

[Matt Timion]

Originally Posted by Compaq888

ok I found out that the belt that is on the alternator also shares the power steering pump and the water pump pulley. So I can't take the alternator out. So what can I do to increase my mpg without pulling out the alternator???

Maybe get a solar panel that will make the car use less my alternator or how does it work?

You can get a shorter belt.

I think the only way to really go without an alternator is to have a number of deep cycle batteries in the trunk. Of course each of these will weight around 30lbs.

I think energy is better suited in finding an alternative to an alternator, like the turbo alternator idea.

[SVOboy]

I hate those big serpertine belts, but thay prolly make more sense. I have 1 belt for 1 task, though the only task that really exists is a/c and alternator.

[red91sit]

I'm liking this turbo alernator idea, We have restrictions in our eshaust either way to reduce noise output, a turbo is slightly less efficient than a regular muffler, but if it's doing work... The only problem I see is the exhaust is VERY hot...

[BEN_EJ8]

Originally Posted by Matt Timion

I wouldn't call 2012 way ahead of me. This is why I said we should make our own instead of waiting.

If you want, I have a T3 turbo that should be rebuilt, but I doubt Ill ever get around to doing it. You or anybody on this forum could have it for dirt cheap to experiment with. I think it would be awesome to create an exhaust powered alternator and save 10% of gas

[GasSavers_gashog]

Has anybody copiled a list of all the things that they tried showing the gains/loss, good and bad of each try, and lessens learned with each try???
that would be a great building tool for everybody passing out the information

[CoyoteX]

One thing I am curious about is if disconnecting the alternator without removing the belt would show the same gain in mileage. The alternator isn't really that heavy and most likely would not be much drag if it had the power disconnected from it.

The advantage would be you could put a switch on the dash so the alternator charges the engine when you need it, but can turn it off for the most part. Like if you had to go somewhere on a long trip and would otherwise not be able to make it without the alt.

Taking this discussion in a strange direction. Maybe make a regenerative braking system by epoxying a bunch of super magnets to the brake drum/rotors and getting a coil near it so when you want to slow down you connect the coils through a bridge rectifier to your battery so it can help make up for the missing alternator. I think the extra weight of gluing 10 neodymium magnets to each rotor and a series of probably 6-8 coils on the backing plate would not be bad, maybe 10lbs total for all 4 wheels. It might be able to get 10-40 amps of current when the coils are connected. The noise generated from the coils when they are on would definately kill your radio reception though. This could be wired to a button or 4 so when you want to slow down faster than normal coasting you hit as many as you need to slow down with. An alternate way of activating them would be raise your brake pedal a half inch or so and set it so the extra travel trips the switches in sequence so you could use your brake pedal lightly to slow down/regen braking and if you need real brakes just push it farther.

I know, I know, I'm nuts but at least I sound like I know what I am talking about

[onegammyleg]

Hi Coyote X

You could use regen braking , and do it a much simpler way.(an alt wont provide much braking effect)
By placing a pulley on a driveshaft you can run an alternator easily.
They do this on rear drive prop shafts in RWD hot rods when they want the alt out of the engine bay.
They put them down near the diff's and run a small belt off the propellor shaft diff flange.
Works fine , but the alt is in a more hostile envornment (no bush bashing) so they can get damaged a little easier.
But assuming you have a FWD car the alt can be mostly still in the engine bay , nice and safe.
You can also switch the alt on and off when required manualy , but if you had it switched by a vacuum switch it could be set to charge only when idling , of course no charge when your sitting still , but there would be when your coasting up to a stop light for example.

During the day not much charge time would be needed.

Overall , probably not much benifit over having it driven off the engine and switched in this manner tho.

[AlexK]

Hey guys I have an idea. Are you familiar with Peltier junctions? They are usually used as thermoelectric coolers for computers and 12V coolers. When you pass a current through it, one side absorbs heat (gets cold) and the other side rejects heat (gets hot). Well they also work in reverse... if you heat one side and cool the other they generate electricity. You could attach one to the underside of your catalytic converter and attach a heat sink to the cold side which would be exposed to the flowing air under the vehicle. I know they are not very efficient as heat pumps, so as heat generators they are probably not good either, but if the heat is free any recovery would be good. I will do some research on efficiencies and report back here.

[AlexK]

The Peltier idea would work but it would be very expensive and you would need a lot of Peltier modules. This one: http://www.tellurex.com/power_modules/p219.html
Generates only 5.7W max and it costs $43. It is about the same as photovoltaics per watt but only works while you drive.

[Silveredwings]

Originally Posted by AlexK

The Peltier idea would work but it would be very expensive and you would need a lot of Peltier modules. This one: http://www.tellurex.com/power_modules/p219.html
Generates only 5.7W max and it costs $43.

They're 4.8V at 1.2A so you'd need 3 in series to get 14.4V (good enough to charge a car battery) at about 17W for $131.85, which might be enough power given that it can run continously*.

If you put 3 of those strings in parallel, you'd get 51W for $395.55, with 4 you'd get 68W for $527.40. I think that's comparable to a new alternator, (though I haven't priced one at a dealer lately) but that may be overkill.

Originally Posted by AlexK

It is about the same as photovoltaics per watt but only works while you drive.

*Well, to continue the photovoltaics analogy, PVs work whenever light hits them, Peltier junction devices should work whenever there is a temperature differential across them. So, if one side is heat-sinked, and the other side is still hot from the engine block, they should still work while the engine is off.