TeamSwift

What do you guys think about taking out the alternator and charging a car battery with a solar panel?

Would 100 watt output be enough to make up the drain from the car?

And most importantly (well second to that) -- would the gas mileage improve much? ie, how much does the average mpg decrease from the alternator?

Any opinions/experience?

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-Martin

It would improve a bunch...cause you'd be pushin that car around almost daily!

all jokes aside . i drove a car home (about 60 miles) by hooking up 2 ,6 volt headlight batterys and push-starting the car . even listened to the radio on the way.
the charging system only puts a load on the motor when the battery is discharged or when you turn something on. the ignition pulls very little power and a large cell could run it. the savings would never offset what a cell bank cost. but it would look cool !

I think everyone is missing the main point here.. Your ignition system requires a higher voltage to produce sufficient spark and only having 12v's isn't going to cut it for you. The higher voltage 14.4v produced by the alt significantly increases the power your engine makes.

Besides how good is a solar panel at night when your driving with the healights on.

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"Don't argue with stupid people. They just bring you down to their level and then beat you with experience."

what type of ignition system. modern computers would def toke more wattage. heavy duty battery would offset weight savings.
we ran my son's 550 honda off of dry cells to do a test run while rebuilding it. lasted about an hour.
neat experiment, but probably not practical. hopefully you have a cheep source for solar panels

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Working with cars is a little like a really awesome date:
You start out thinking this to be something simple and straightfoward;
Four hours later, you're laying under her panting and cursing,
And things are a lot more complicated than you thought.....

I'm totally agreeing with TheINCride about the lack of an alternator and how sucky the car will run.

The alternator belt snapped on my firefly, and performance immediately dropped to something akin to a moped. That poor 3 cylinder was just struggling to make it to the nearest part source (I /just/ made it as the battery died).

However, when I had my Volvo 740, when that alternator belt snapped, I was able to to drive about 10 kms with no performance loss. So, Hillbilly, I don't doubt in any way that your son's 550 Honda ran on just battery power alone. If it were a Civic, it could be a different story.

Wazerface, you have a good idea, but if you wanted to do something like that realistically, you'd need a /lot/ of solar cells to do it. At least, enough to produce 14v and a 40 amp draw. That being said, TheINCride is right again about driving at night. You might be able to charge your battery with solar sells, but come night time, that battery will last about 5 minutes.

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Rice: Race Inspired Cosmetic Enhancement

How about a kickstart and a magneto ignition?

even if you lived near the equator, with some really good sunlight, the cost of the solar cells would FAR outweigh the cost of fuel savings. i looked into some solar cells once, and $1500 usd wouldn't even get me 5 amps of current (at 15 volts). but it's a great idea if somebody ever comes up with a more efficient solar cell.

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Favorite thing to hear at my parties (or in my car), "WHAT?!?!?!?!?! I CAN'T HEAR YOU!!!!!!!!"

But you see there is only so much energy you can harvest from any source. Efficiency is not the problem! It is the amount of convertible energy.

Move to Mars. That might be more simple. [/code]

come to think of it all of my best rides had a kick start, and wire rims

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Working with cars is a little like a really awesome date:
You start out thinking this to be something simple and straightfoward;
Four hours later, you're laying under her panting and cursing,
And things are a lot more complicated than you thought.....

100 watts at 12 volts is 8.3 amps. I wouldn't try running the whole car with that little power. Supplementing the alternator's output with a PV panel may not be a bad idea though. The alternator will ensure that your vehicle is always charged, but when sunlight is available, a percentage of your electrical generation can come from something other than your engine. Also, you won't have to mess around with different pulleys and belts to keep your water pump running. The other benefit of having a PV panel added to your electrical system, is that your car will never need a jump start even if it sits for months without starting (as long as it's outside of course).

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the lack of daylight up here in AK during the winter sure does suck for solar power but summer time it might be worth a try, except for that whole lesser voltage problem

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Straight roads are for fast cars but turns and curves are for fast drivers

On a bright sunny day I had my alternator pack it in 350 miles from home. I had a spare at home so I didn't want to buy one where I was. I stopped at the nearest place I could and bought the largest solar panel they had. I hooked it up and disabled my daytime headlights and ran absolutely nothing extra for draw on the battery, strictly brake lights turn signals and engine draw. By the time I made it another 100 miles I had to buy a battery because I couldn't make it any farther. I barely made the last 250 miles into my driveway on the new battery. At least I had a use for the battery I bought but the solar panel didn't get used again. That's my experience.

solar power = expensive crap that does nothing

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Silver 2000 Firefly 4DR; 16V SOHC, 3 to 5 speed swap, install PS and AC, remote and auto start, PL, PW, kill and start switch, Valentine 1, behind-bumper CAI, 55MM TB with coolant-bypass, polyurethane-fill engine/shifter mounts, modified to short shifter, upgraded electrical system, CS130 alternator, 90/160W headlights + relay mod, ceramic H4 plug/harness
To do: finish stereo, 4000K H4 HIDs, short block replacement
'sponsored' by Captain Crunch, Lordco, Felpro, Permatex, Royal Purple

It's been done and the modders swear it increases mpg by removing the alternator load from the engine. There are a couple of guys on Geometroforum.com who have built rear shelves for solar panels. Costs about $100 to do and the panels are available on Ebay (or HarborFreight). Check out Ecomodder.com for a number of projects that remove the alt and run with a couple of batteries instead. A heavily modded Previa on ecomodder comes to mind immediately.

Brian

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'93 Geo Metro

I wonder how their doing driving at night lol.

If your really serious about trying it, I would recommend replacing as many of your lights as possible with high efficiency LED's.

When it comes to solar panels, direct light is best, if your mounting them inside and up against your windows, you won't get too many of them. Odds are to get good power, roof mounted is what you will need to do. Then there is the issue with weight, if your getting just the inexpensive solar panels, they will weight a ton so now your adding a good amount of weight to the car. If you want to do it right, you will be buying far more expensive light weight and thin solar panels. Then there is your wiring, your voltage regulators, and only being able to run during the day.


'Now, with those limitations, suppose you see an increase of 2MPG, and you spent several hundred at least on the system. You now have all these limitations on when and where you can drive, driving on a cloudy day, you may only get half the distance as before or you will need double the panels.

I think I will keep my few hundred dollars+, be able to drive at night or whenever I want, use that money to get me an extra 5,000+ miles.

Just keep the alternator there and add the solar panel. Also, use regenerative braking (uses braking power to charge the battery). The add-ons will take the load off the alternator, but the alternators still there if needed. And yes, replace as many lights as possible with LEDs.

Thanks for sharing information.. I have been thinking of installing solar panels but the cost of installation is pretty high.. I would love to save some money and get solar panels ASAP.

I think it is effective. I am not sure how these panels will work in night so you need to conserve power..

Here is simple mat about your alternator . Our alternators produce 45-55 Amps at 14,4 Volts which makes 650-790Watts . Your 100Watts panel would not provide enough power especially at night when you need it the most or in the winter when you need it even more. Your headlights draw about 10Amps by themselves , where is the power for about 20 more light bulbs and the ignition and lets not forget the starter?

If you look how much power our alternators use to produce 790Watts, you will realize, at max that is only 1 HP. Most of the time alternator is producing far less then its max output. So removing it you would gain maybe 1/2 mile a Gallon. Do you think its worth the headache?

You could probably see same gain in mileage just by checking your tire pressures more often and keeping it 5 pounds higher then recommended