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Old 08-10-2018, 07:27 AM   #1
braol
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Default Headlight Electrical Draw

I'm looking to see what everyone's average amperage draw is when the headlights are on? I'm getting about -8 amps indicated on my ammeter...it seems excessive. I figured that with the headlights on the ammeter would drop but not dip so low.
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Old 08-10-2018, 08:14 AM   #2
Kurt in NJ
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Default Re: Headlight Electrical Draw

I have 35 watt halogens, 2 tail lights stock bulbs, including ignition,dash light 14 amps, all else stock , never dead battery, never charged except by driving,--- 35%lights on
If you read the owners instruction book it says there WILL be a discharge showing when driving with the headlights on, and at idle, --- it's normal, the charge rate needs to be adjusted for your use--- mine is about 14 amps, last battery lasted 16 years so it's a good setting for my use , I do leave the cover band off, and it's probably time to take the generator apart to service it, hasn't been worked on in over 40years
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Old 08-10-2018, 10:39 PM   #3
Mike V. Florida
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Default Re: Headlight Electrical Draw

I you are using the grossly inaccurate ammeter in the car, then you are just fine!
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Old 08-11-2018, 02:06 AM   #4
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Default Re: Headlight Electrical Draw

Several variables that affect the draw. Ammeter accuracy being one. The type of headlight and tail light bulbs is another, and where the third brush of the generator is set being a third, and the condition of the battery being yet another. I am not sure there is an average sort of number that you could say is correct.
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Old 08-11-2018, 05:32 AM   #5
aermotor
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Default Re: Headlight Electrical Draw

Fun Projects regulator will address all your day/night amperage concerns.

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Old 08-11-2018, 08:18 AM   #6
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Default Re: Headlight Electrical Draw

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Originally Posted by aermotor View Post
Fun Projects regulator will address all your day/night amperage concerns.

John
I agree. I have my generator setting such that running with lights on I have about zero charge. With the regulator, in the day without lights it charges the battery up quickly, then holds a small positive charge.
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Old 08-11-2018, 09:26 AM   #7
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Default Re: Headlight Electrical Draw

One 50 CP bulb is about 36 watts, or 6A at 6V, and increases with higher voltage. Total head/tail lights + coil current draw will run 15-16A at 7V with a well-charged battery. The cutout contacts close at about battery voltage, so your meter shows the battery discharging 8A, the rest being provided by the generator.

You could adjust the 3rd brush for more current, less discharge of the battery, but I wouldn't want to push the generator over 12A continuous. Depends on how much driving you expect to do with headlights on. If not much, you're probably OK as is. That brush adjustment is more an art than a science.

Last edited by Badpuppy; 08-11-2018 at 10:29 AM.
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Old 08-11-2018, 07:37 PM   #8
Tom Wesenberg
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Default Re: Headlight Electrical Draw

Stock headlamps and taillight draw about 8 amps. My 28 is all stock and draws 8 amps.
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Old 08-11-2018, 09:55 PM   #9
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Default Re: Headlight Electrical Draw

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Stock headlamps and taillight draw about 8 amps. My 28 is all stock and draws 8 amps.
Right, Tom. That's all the stock generator was designed to handle. I was assuming worst case - 2x50CP in front + 2x15CP in back, which seems to be all the rage these days. That's almost 100W total. Plus another 35W or so for 2 brake lights. So to avoid generator meltdown it's necessary to rely on battery reserve to run this set of lights. Then when you get home, shut off your Christmas tree and keep the engine running until the battery comes back up.

As for me, I swapped in a 6V 30A alternator, which can handle all that, and has a built-in regulator so I don't have to worry about a 3rd brush setting.
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Old 08-12-2018, 03:42 AM   #10
Tom Wesenberg
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Default Re: Headlight Electrical Draw

The long generator can safely produce 12 amps continuous, and the powerhouse can give 15 amps.
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