Given that I'd like to cut down the electrical usage in my car, because of a marginal alternator for the power I'd like to be using, what about replacing some of the incandescent lamps with LED's nowdays? Like tail lights and turn signals, running lights etc? Do they have viable LED replacements for them now, that use less current and put out as bright a light?
Yes, they do. You can get them at AutoZone.
I assume you want to power a big stereo or similar thats exceeding the alternator rating. Lets suppose that this item wants to draw 800W, or about
70A. Stop light bulbs are maybe 30W, tail lights are say 14W. Replacing these with LED units that draw maybe 15/5W won't solve the problem.You cannot replace headlight bulbs with an LED array replacement unit because the reflector is designed for an incandescent point source. A headlamp has to be designed for a LED array source.
Your only viable solution is install a higher rated alternator.
SD
As Stewart correctly points out, substituting LED bulbs for the tail lights, brake lights, and turn signal indicator lights won't reduce the draw enough to solve the problem. It may be more cost-effective to find an air purifier designed to run on 12 volt systems than it is to modify the car. Depending on what type of system you have, the only component that actually needs 120 volts is the fan, while an internal transformer drops the voltage for the actual filter/purifier.
For example, you may be able to find a 12 volt air purifier made by whoever made the purifier in your car.
A friend sells Living Air purifiers, which have both 120 and 12 volt systems.
As a gadget geek, I'm always looking for cost effective solutions to my wants.
But some of you guys here have already told me that this engine wouldn't keep up with a larger alternator, that I'd need a larger engine, less gas mileage etc.
Not yet, that I know of. I've suggested it to Austin Air though.
But they make air cleaners that not only have HEPA filters, but pounds of charcoal, instead of the grams of charcoal impregnanted mats that most air cleaners have.
Ask them how many pounds of charcoal they have in them and how many CFM they move.
The Austin Air HM200 I have in the back seat, has about 7 LBS of charcoal and other gas adsorbing media in it.
I think most car air cleaners are little more than overprices placebos. And IMO Sharper Image are scum for selling those poisonous ozone machines.
Just make sure they're based on science and not just slick TV ads. :)
And you'll spend a small fortune doing it - some of those LED conversion lamps are north of %50 each. The payback will take forever
- they're only practical for high-vibration uses like unsprung utility trailers where regular lightbulbs get bounced to death.
Adding a larger alternator of the same type you have now is easy - they use the same frame size for anything from a 60A to a 90A or 100A unit, and the wiring will plug in just the same. The only hard part is putting in a larger charge wire from the alternator output stud back to the battery, to handle all the extra amps you are making.
Go find a good local Auto Electric rebuilding shop - they can look at what you have, tell you what it puts out now, and what they can fit in that puts out a lot more.
The EFI Computer can easily bump the idle speed up to cope with spinning a bigger alternator.
Another stop-gap trick is to get a smaller pulley for the alternator
- you overdrive it so it spins faster and puts out more power at idle. But be warned, if you change the pulley and you like taking the car up to redline regularly you can overspeed the alternator and make lots of shrapnel out of it...
If this is a simple HEPA and Carbon Filter, there is just a fan motor pushing the air through, and that's your main power sucker. You can get a 12-volt motor to run the fan directly, the hard part is the mounting and shaft length and diameter to mount the right fan blade. Or you take the factory fan out and use a small 12V radiator fan motor.
If it has an electrostatic capture grid, there is a high voltage low current power supply to get 10KV - 25KV DC at a few milliamps. For that, you go find a power supply that will go straight from 12VDC to
25KVDC, and save the losses in the 120VAC conversion step.
Ozone generators are just a High Voltage Power Supply and a set of static transfer spikes to charge the air. They don't do much, and Ozone is rather corrosive in any great quantity.
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The Austin Air HM200 is recommended for areas up to 700 SF and has a capacity of 200 CFM. If the 700 SF room has 8 foot high ceilings, the room has 5600 cubic feet. At 200 CFM, it theoretically takes 28 minutes for a complete air change in the room.
A Corolla wagon has interior volume in the neighborhood of 120 to 150 Cu. Ft. At 200 CFM, your purifier can do a complete air change in less than a minute, which sounds like overkill to me.
Assuming 150 Cu. Ft. of air in the Corolla, a 10 CFM fan would change the air every 15 minutes, still faster than the Austin Air HM200 is designed for.
Does your filter use electricity only to circulate air past the filter media? If it does, perhaps you can fabricate a shroud that fits over the filter's air intake with a 12V fan that moves air into the shroud, kind of like a kitchen oven's hood that moves air in reverse. The shroud would avoid messing with the filter itself and potentially ruining it, and being able to move air through the filter would give you the advantages of the nice filter without the big power draw.
ozone is also bad for the plastic and rubber in the car.
I like to buy stuff that I can see and touch firsthand, not just on a screen. If I could, I would take the gadget apart and put it back together before buying it. ;-)
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