Test: Alternator vs. no alternator = 10% MPG gain @ 70 km/h

[MetroMPG]

Originally Posted by Bearleener

Assuming an alternator efficiency of 55%, an engine efficiency of 29%, the electric power consumption is 1.96 kW * 0.55 * 0.29 = 313 W.
Sounds reasonable (somewhere here I'd seen that keeping the engine

Bearleener: I did a more accurate audit of the electrical demands of my car, and it's much lower than I originall guesstimated (based on someone else's Honda Civic figures).

FYI the results are here: http://ecomodder.com/forum/showthrea...olts-8908.html

[Nerys]

very cool post thank you so much! I knew it did not take much power to run these things. when my alt died first day I got my metro it died so STRANGELY I did not immediately suspect alternator until I saw the lights DIMMING but the engine still ran eventually the enginer started having trouble but as soon as I turned off the headlights it was fine again (thats how I knew it was a power issue)

60watts. Amazing :-)

[Bearleener]

@MetroMPG: Thanks for those data, that's all amazingly low, especially the 60 W to run the engine!

@Nerys: yeah, the 29% refers to the heat of combustion.

[JackMcCornack]

Thanks MetroMPG, I think I'll go to an auto electrical shop and see if I can set it up with two regulators--one that's the default regulator and is set to charge to slightly less than full charge, and one that switches on with braking and is set to charge full charge. And bartender, I'll have one of what the man in blue is drinking! :-)

[EDIT--Oops, I was still on Page 5. Nerys, my whimseyed response was to...
>I had assumed when people say that they mean 29% of the atomic energy in
>the structure of gasoline IE half of what comes out of a matter antimatter reaction
...which seemed an unusual enough assumption to be worth a smiley.

But with the info on Page 6, and the fact that my Kubota only needs as much power to run as does a flashlight (it has a fuel valve solenoid to kill the engine if the electrical system fails), if I use LED turn signals and run with my headlights off, maybe all I need is a solar panel.]

[Nerys]

well whenever I hear "total energy of" this to me means 100% conversion of the matter to energy. the only know way to do this is a matter/antimatter reaction (even nuclear only converts a tiny fraction of total energy of matter to energy.)

so I heat people say 20% 30% and I am thinking your nuts. if you got 29% the energy out of gasoline you could circle the globe on a gallon of gas or something nutty like that :-) I mean a few micro grams of antimatter could take us pretty much anywhere in the solar system. a Gram anywhere in our part of the galaxy :-)

then while reading your post it dawned on me that it was NOT 29% of the available energy of gasoline but 29% of the HEAT you get when you combust it which makes a lot more sense but is very deceptive. Cars are actually less than 2% efficient

when people understand THIS it starts to get easier to describe why EV's are sooo damned good :-)

I think there is enough roof area and back window area for 100watts of solar panels. (which should net you 60watts in less than ideal conditions)

in theory combine this with 2 deep cycles and your "parked" time in the sun should be enough charge time to make up for other usage such as driving at nights with the lights on Especially if you convert as much as you can to LED's

ie you might be able to stay "unplugged" except once in a while if you do a ton of night driving and it rains for a few days then you might have to plug in a trickle charger to "top off" the batteries.

Put it this way its close enough that my curiosity is peaked :-) I am even looking into LED headlamps. but man are they expensive $120 a pop and I would need at minimum 2 and very likely 4. (800 lumens a pop 10watts consumed) so if I needed 4 my power load would drop from 100 watts to 40watts if I could get away with TWO (say in well lit cities etc..) 100 watts to 20 watts would make a huge difference :-)

no need to mount panels and stuff I would use the Flexible panels and attach them directly to the roof like a SKIN. Maybe even the hood too (but then you start to screw with aesthetics) if you did not care about aesthetics you could probably get 200watts of panels on the car and NOT screw your aero. Then toss another panel in the hatch area (someone already did this and it fits perfectly)

now you should have MORE than enough power to get rid of the alternator if you get the LED conversion done and are careful with power usages.

heck maybe even get a few peltiers in on the action if we can make them produce some usable watts. they would be especially useful in the WINTER where you have nice cold air for the differential requirements AND at the same time winter is when solar will be lacking (less sunlight and more angle)

[SVOboy]

Aren't the flexible panels much less efficient though, making them less than ideal for the limited-space adventures of car solar?

[Nerys]

I would think with that much surface area they would be "good enough" especially if you used hood space. remember anything over 100watts and your golden.

[Bajascoob]

The newer diesels need power for engine management, throttle control etc.

[gone-ot]

...sorta begs-the-question, *why* can't cars have AMP gauges as they did in the 'olden' days (as well as VOLT gauges)?

[orange4boy]

LOL, You wouldn't want anything distracting people from texting while they drive!

Also, people would get a clue about how much juice all their accessories are sucking. You really don't want people to have a clue do you?

I put an analog one in my alternator-less Previa. Heater fans and window wire defrosters are your enemy!

Speaking of data, a good PC based scanner can graph you all kinds of data. It's all there. One day perhaps they will let us access it with a stock readout like some clever prius folks have done with CAN-View.

I'm getting ready to run the 12V side of my Prius on deep cycles once I get hold of a good DC-DC converter. This time I'm actually going to test it.