amps/watts for driving lights?

[henry roberts]

i was wondering how many amps i will have available to run the headlights and driving lights. if you can give me a figure for watts of lighting that would be even better .

i will be running a 35A 12V generator, a warm 1200/1380 engine with a bosch blue coil. looking for the amount available with tail lights, brake lights, wipers and blinkers on.

thanks.
henry.

a very rough mock up of where i'm heading.



or if i have the amps more like

[Shadd]

Use the Wav formula.

Watts = Amps x Volts

35A x 13V = 455W (although the battery is called "12V" working voltage of the gen is ~13V)

Headlights = 126W (both high beams + markers)
tail lights = 16W
brake lights = 42W
wipers = ~100W(guess due to them having an 8 amp fuse)
blinkers = 16W
Ignition coil = ~40W

Total = ~340W
Headroom = ~ 115W

So you can run two 55W driving lights. Just keep in mind that 35 amps is just a rating. Real world numbers depend on engine RPM. Also the generator does not have a 100% duty cycle so pushing the limits 100% of the time will not end well.
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[slalombuggy]

Ohm's law calculator

http://www.ohmslawcalculator.com/ohms_law_calculator.php

brad
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BB Buggy 121.253mph @ Bonneville 2012
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Raisin cookies that look like chocolate chip cookies are the main reason I have trust issues

[henry roberts]

thanks.

[beetleseb]

I think the windscreen wiper may be a bit lower

its def worth popping a meter across and measuring the resistance. Then use V=IR to work it out

This is especially useful if your using a voltdrop to run your ww's as you can measure across the two and take that into your calc.

I love the look of the 4 lights. Def worth looking at lower power bulbs/leds or something clever like twin batteries and a management system to let you run them.

Seb
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Wanted - OG 50 split bug door panels, brown mats and old running boards

[Kapt. Q]

[henry roberts]

in my state you aren't allowed to have more than 6 forward facing lights (twin headlights = 4 lights but we have no problems there ) i have never looked into the legalities of how many can be on at once...

[bajamike560]

[Rome]

I also have driving lamps on all of my VWs (see a few of my gallery photos). For low-current draw, I'm interested in these:

http://www.superbrightleds.com/cgi-bin/store/index...H3-WHP.htm

They would allow you to run the additional 2 lamps with your generator. If you do pursue the 2 lamps on the hood, you probably know to add some sturdy reinforcing metal plates on the underside of the hood so that the lamps do not shake during normal driving.

BTW I drive with my headlamps on all the time in my VWs as well as my modern daily driver, after being hit by a Jeep in '88 who claimed he never saw me in the next lane.

[dandand]

In 1961 a buddy and I found some 6 volt aircraft landing lights rated at 100 watts each. So naturally we hooked them up to our cars - his was a 1958 VW, mine was a 48 Chev. Both 6 volts. We used relays, 10 ga wire, etc. Did the job right!
We noticed right away that the other lights dimmed noticeably when these babies were turned on! So we split them - 2 switches and 2 relays. The RH light was wired thru the Hi Beam, and was aimed down the center of the road. Obviously this side was used sparingly, like on deserted country roads.
The LH light was aimed down the right side of the road, and was aimed toward the RH curb, not too far down the road. We reasoned that we could use this on the freeway as long as we didn't get too close to anyone in front of us.

The night we did the testing and aiming, the local police were called due to a complaint from the girls college across the athletic field we were using. Needless to say, the police were not impressed, and pointed out that there was a limit to the brightness allowed on the highway. We got by only because we rarely used them, and then only for a few minutes at a time. Now you see pseudo off road racers with 4 and even 6 lights equally as bright.
If you haven't already thought of this, I suggest you use a separate headlight relay for each pair, rather than running all current directly thru the switches. Use healthy sized wire, solder the connections, and check the power leads for hot spots at the connections, etc.
Just my 2 bits worth.
Dan