Harbor freight 6" light
- Thread starter racie35
- Start date
That's a little bitty battery!
Let's see... 55w at 12v. Simple DC power equations here (P=IE) so your current draw (rearranging the power equation to I=P/E) gives you 55W/12V... so around 4.5a(ish)
So let's say that, continuously, that's 4500mAh. On a 10mAh battery (10/4500) is right at 8 seconds of life.
My cell phone has a battery bigger than 10mAh lol
(a 10Ah battery would last a little over 2 hours with a 4.5Ah draw)
Let's see... 55w at 12v. Simple DC power equations here (P=IE) so your current draw (rearranging the power equation to I=P/E) gives you 55W/12V... so around 4.5a(ish)
So let's say that, continuously, that's 4500mAh. On a 10mAh battery (10/4500) is right at 8 seconds of life.
My cell phone has a battery bigger than 10mAh lol
(a 10Ah battery would last a little over 2 hours with a 4.5Ah draw)
I just looked at the HF website. I assume you are referring to the chrome headlight? Looks really cool!
I only have one concern, and that's your whizzer alternator. Is it rated for that much power draw? If not, is it fused? I really don't want to see you burn out the stator coil on your whizzer.
Otherwise, awesome find!!
I only have one concern, and that's your whizzer alternator. Is it rated for that much power draw? If not, is it fused? I really don't want to see you burn out the stator coil on your whizzer.
Otherwise, awesome find!!
Yes it's chrome and it's nice looking. The Whizzer has a regulator for voltage in the system. The stock light on one is 25w so I guess draw is doubled. I may go out and hook up a wiring plug to test the system on one of mine today. I guess you could always change the bulb to a 25w if worried. The bulb in the hf is an h3 halogen so maybe?
The voltage regulator only maintains the system voltage at 12v. It's not a current regulator.
Think of it like a garden hose. Let's say that the garden hose has a pressure regulator ( opens/closes to maintain output pressure). If you hook up a fire truck to your garden hose, there will be a huge demand on your garden hose to supply the fire truck. The pressure regulator will work over time to maintain the pressure coming out of the garden hose (that's the voltage) but the huge demand means that it's got to open up more to allow more water through (current). It's not going to be able to keep up with the demand.
If the current draw is too much, the stator coils can burn out. Kind of like putting a fork in a socket. It draws too much current (short circuit) and trips a breaker. If there wasn't a breaker there, the wiring would overheat and catch fire.
Anyway, I'd try to find out the rating of that whizzer changing system, then fuse the output. If it blows the fuse, find a lower rating bulb.
I will be visiting HF soon for one of those lights.
Think of it like a garden hose. Let's say that the garden hose has a pressure regulator ( opens/closes to maintain output pressure). If you hook up a fire truck to your garden hose, there will be a huge demand on your garden hose to supply the fire truck. The pressure regulator will work over time to maintain the pressure coming out of the garden hose (that's the voltage) but the huge demand means that it's got to open up more to allow more water through (current). It's not going to be able to keep up with the demand.
If the current draw is too much, the stator coils can burn out. Kind of like putting a fork in a socket. It draws too much current (short circuit) and trips a breaker. If there wasn't a breaker there, the wiring would overheat and catch fire.
Anyway, I'd try to find out the rating of that whizzer changing system, then fuse the output. If it blows the fuse, find a lower rating bulb.
I will be visiting HF soon for one of those lights.
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I'm not sure but I think this Whizzer is 21w....so yes if I use the light for more than looks I'll need to do something. You'll like this he light, but one thing....I can't click on it on their website anymore so they may be discontinuing it. I'm gonna grab an extra one.
That's Silverbears favorite head light. He cuts the bulb socket out of them and puts a led flashlight bulb in it's place.
Steve.
Steve.
I've been thinking about building a light like this. Halogens give such a beautiful light spectrum.
Imagine the light drawing it's power from a 10 amp/hour SLA battery. I've actually done just this before. It gives about one hour of light. And that was usually enough. Then I'd recharge the battery overnight.
But now imagine mounting a 12 Volt bottle generator on the bike. Add in an automotive voltage regulator and have the bottle generator charging the battery. Operate the generator at almost all times. Even in the daylight.
This is roughly equivalent to racie's situation with a Whizzer generator that's not strong enough, in itself, to power the light.
But neither of these generators would need to power the light. They'd merely be slowly filling an electron pool which the light is free to drain at whatever rate it chooses.
This sounds to me like a pretty good setup. But I'm no electronic engineer. So I might have missed something.
Still, I'm pretty likely to give it a try.
Imagine the light drawing it's power from a 10 amp/hour SLA battery. I've actually done just this before. It gives about one hour of light. And that was usually enough. Then I'd recharge the battery overnight.
But now imagine mounting a 12 Volt bottle generator on the bike. Add in an automotive voltage regulator and have the bottle generator charging the battery. Operate the generator at almost all times. Even in the daylight.
This is roughly equivalent to racie's situation with a Whizzer generator that's not strong enough, in itself, to power the light.
But neither of these generators would need to power the light. They'd merely be slowly filling an electron pool which the light is free to drain at whatever rate it chooses.
This sounds to me like a pretty good setup. But I'm no electronic engineer. So I might have missed something.
Still, I'm pretty likely to give it a try.
But wait......I can think of one problem with my idea.
An automotive voltage regulator is certain to want alternating current as input. And I'll bet it won't work with DC input.
But that's probably not fatal. I'll bet a voltage regulator for DC input can be found.
An automotive voltage regulator is certain to want alternating current as input. And I'll bet it won't work with DC input.
But that's probably not fatal. I'll bet a voltage regulator for DC input can be found.
Automotive voltage regulators don't use AC. The output of the alternator is immediately rectified by a full wave bridge, and usually internally regulated as well.
An easy voltage regulator circuit can be made with a bank of LM7812 regulators and a couple of capacitors. Wire the regulators in parallel for added current capacity.
An easy voltage regulator circuit can be made with a bank of LM7812 regulators and a couple of capacitors. Wire the regulators in parallel for added current capacity.
I know this...my Whizzer uses a 25w headlight,plus there's a small tail light on always when it's running. They are on always with the ignition switch. The battery isn't very good...1.2 ah,though I think you can get a better one that fits the box.
Anyhow, the battery stays charged always, so it at least handles that stuff. It must charge at a higher rate than I thought.
Anyhow, the battery stays charged always, so it at least handles that stuff. It must charge at a higher rate than I thought.
BGW is right. You'll get about one hour. 55W at 12V requires a little over 4A to run for one hour, however the reality is that the voltage doesn't stay at 12V until the end. So with the 10AH battery you'd think you get 2.5hrs, when in reality you'll only get about one hour if that. I'd say 40 minutes at most.
Better IMO to get about 30W of LEDs. The same 10AH battery will give you at least 2 hours of quality bright light.
Better IMO to get about 30W of LEDs. The same 10AH battery will give you at least 2 hours of quality bright light.
Also forget about getting an LED bulb that's the same size as the halogen in there. Some of them may be bright but the lens geometry isn't suited for LED and it will be a waste.
