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-   -   Total Geekiness (http://www.bikeforums.net/electronics-lighting-gadgets/42629-total-geekiness.html)

DannoXYZ 12-09-05 01:45 AM

If you're driving a 12v halogen at 11.1v, you'll be losing A LOT of light, much more than -9%, probably closer to -15%. Better to run another cell to get 14.8v and use an efficient, nearly-lossless regulator to keep it around 13v. Then you'll get brighter light and longer capacity due to the extra cell and the regulator will provide a longer run-time of a fixed brightness. Rather than super-bright at first that fades faster into a dim 2nd half of the charge.


Quote:

Originally Posted by wmgardner
I like your setup here and think I'm going to try to build something comparible for my power source. I think I'm going to go with a 5ah setup, so I'll probably buy these: http://www.batteryspace.com/index.as...OD&ProdID=1158

They're cheap and I think they'll provide plenty of power for my commute if I charge every day at work. A question I have is why you built your power brick to supply 13.2V instead of a flat 12V. Is there something I'm missing here? Should I buy 11 of these batteries so that I can get 13.2V or can I get by with 10? Also, what smart charger do you recommend for this type of setup (assuming I go with the C batteries instead of your D's).

Thanks everyone for all of the great information. I'm learning a ton (and having a great time). :D

I got 13.2v so that I can overdrive the halogen light by about 10% and get 20% more light out of it. :) The charger I use is a Battery Tender that detects full-charge through a voltage-plateau I believe. So it stops at 12v or 13.2v or 13.8v for SLA batteries, varies depending upon what's hooked up. Another source for smart-chargers are the Black & Decker chargers for cordless-drill batteries. Some of the smart-chargers even have an adjustable trigger-point for when they switch from charge to trickle mode.

Old Dirt Hill 12-09-05 07:13 AM

Quote:

Originally Posted by DannoXYZ
The charger I use is a Battery Tender that detects full-charge through a voltage-plateau I believe. So it stops at 12v or 13.2v or 13.8v for SLA batteries, varies depending upon what's hooked up. Another source for smart-chargers are the Black & Decker chargers for cordless-drill batteries. Some of the smart-chargers even have an adjustable trigger-point for when they switch from charge to trickle mode.

So let's say that I use a battery pack similar to the one you setup. Although the Battery Tender looks like a pretty nice (and expensive) charger, could I get by using something like this?:

http://www.batteryspace.com/index.as...OD&ProdID=2051

Sorry for the dumb questions, but I'm pretty new to this stuff. I'll make sure to get some pictures up once this is completed as is looks pretty cool on my bike so far. :D

alwier 12-09-05 08:27 AM

This is a great site for battery questions...great tips on run-time estimation and how to chose type of battery for application.
http://user.fundy.net/cyclist/bikecurrent-FAQ.html

If you add an extra cell in series to increase voltage, there is no extra increase in actual runtime or aH. Unlike a cell added in parallel. But in parallel, there is no increase in voltage.

As for the Philips IRC lights, they are not "overvoltaged". The reflector has an infra-red coating added to it. The coating increases the filament temp without increasing power-usage. (hotter filament=brighter light)

Osram also makes an IRC, but I have only found it in the 35->50W version.

GlowBoy 12-09-05 12:33 PM

Quote:

Originally Posted by DannoXYZ
If you're driving a 12v halogen at 11.1v, you'll be losing A LOT of light, much more than -9%, probably closer to -15%. Better to run another cell to get 14.8v and use an efficient, nearly-lossless regulator to keep it around 13v.

I got 13.2v so that I can overdrive the halogen light by about 10% and get 20% more light out of it. :)

Thanks for the feedback and link, guys. I hadn't yet thought the effect of dropping the voltage by 9% all the way through. Looks like that will drop the effective wattage by 15%, and light output by 30%. Yikes. Makes sense of course -- if overvolting bumps up the efficiency (basically twice as fast as it increases the wattage), undervolting would cause the reverse to happen.

Bumping all the way up to 14.8v Li-ion (with a PWM regulator) would work for the halogen, but I'm also going to be running Xenon strobes and a Luxeon III LED (in an MR16 package, rated for nominal 12V) with this system too .. those can't run off a PWM regulator, and hooking them up directly to the higher voltage would likely blow those out pretty fast ... so I'd either need 2 regulators or live with the inefficiency of the conventional regulator. In any effect, this ends up adding more complexity to the system than I'd like without much benefit.

So now I'm thinking it will be better just to stick with a 12V or 13.2V NiMH system, despite marginally more weight than a Li-based system and the fact that I'll have to put the battery in a water bottle myself. Will the Night-Sun/Lightman 12V strobe run OK off a 13.2V system, or does it really need to be hooked up to a (nominal) 12V source?

DannoXYZ 12-09-05 11:28 PM

Quote:

Originally Posted by alwier
If you add an extra cell in series to increase voltage, there is no extra increase in actual runtime or aH. Unlike a cell added in parallel. But in parallel, there is no increase in voltage.

Yeah, you don't get more capacity with extra cell in series if you hook it directly up to the bulb. It'll actually consume more current, be brighter and discharge the entire pack faster. However, if you use a switching-regulator with very minor loss, it will output a steady 12v output even when the battery's at 14.8v. This runs the bulb at a lower amperage than if you hooked up the battery directly. You'll get a longer run-time before the battery discharged to 12v. It flattens out the sloping discharge-curve and makes it wider; gives you longer run-time until a certain discharged level.

TheDL 12-10-05 04:12 PM

Well...they're a week or two late but here they are! Pics of my "Geekiness" headlight in final form. You can click on the pics to see a larger version.

On the rack, that's the 10ah SLA battery covered by a small canoe dry bag I had. Under the cover is the 5amp mini fuse. It's held to the rack using two 1" nylon webbing straps on a no-slip pad. The wires are inside a 1/4" loom, the switch box is silicone sealed (not the prettiest), the switch has a waterproof boot on it. The connection from the switchbox to the light itself uses a weatherproof trailer connector. She rocks 37.5watts for 2.5~3 hours...beyond that...I don't know, haven't had to run it that long!

http://img182.imageshack.us/img182/5...00013jr.th.jpg
http://img182.imageshack.us/img182/8...00021lc.th.jpg
http://img209.imageshack.us/img209/6...00041nq.th.jpg
http://img182.imageshack.us/img182/3...00059ee.th.jpg
http://img182.imageshack.us/img182/8...00075yz.th.jpg
http://img182.imageshack.us/img182/7...00068xx.th.jpg
http://img227.imageshack.us/img227/7...00115fu.th.jpg

jz19 12-10-05 09:57 PM

[QUOTE=TheDL]Well...they're a week or two late but here they are! Pics of my "Geekiness" headlight in final form. You can click on the pics to see a larger version.

On the rack, that's the 10ah SLA battery covered by a small canoe dry bag I had. Under the cover is the 5amp mini fuse. It's held to the rack using two 1" nylon webbing straps on a no-slip pad. The wires are inside a 1/4" loom, the switch box is silicone sealed (not the prettiest), the switch has a waterproof boot on it. The connection from the switchbox to the light itself uses a weatherproof trailer connector. She rocks 37.5watts for 2.5~3 hours...beyond that...I don't know, haven't had to run it that long!
QUOTE]

Nice job! You only need to add an amber strobe to the mix and you will be done.

GlowBoy 12-14-05 03:24 PM

Question on NightSun strobes, for anyone who knows:

Speaking of amber strobes, my 12V NightSun/Lightman strobe arrived yesterday (as did my Optronics housings, subject of a later post). It mostly looks straightforward to hook up to the system I'm building, Except there's no indication of polarity on the supplied connectors. The instructions say nothing about this either, except just plug it in to your NightSun battery - which of course I don't have because I'm making a homebrew system. Anyone know which side is + and which side is - on these things? Or is it polarity protected so I don't have to worry about it?

LittleBigMan 12-14-05 04:43 PM

Quote:

Originally Posted by GlowBoy
Speaking of amber strobes, my 12V NightSun/Lightman strobe arrived yesterday...there's no indication of polarity...Anyone know which side is + and which side is - on these things? Or is it polarity protected so I don't have to worry about it?

I'm pretty sure it's protected, but I'll check my Lightman strobe when I get home to be sure, and post it tomorrow.

(No indication of polarity tells me it's probably protected, but it's better to be safe than sorry. If you were hoping of hooking it up tonight--sorry! :) )

LittleBigMan 12-16-05 07:53 AM

Quote:

Originally Posted by LittleBigMan
I'm pretty sure it's protected, but I'll check my Lightman strobe when I get home to be sure, and post it tomorrow.

(No indication of polarity tells me it's probably protected, but it's better to be safe than sorry. If you were hoping of hooking it up tonight--sorry! :) )

Ok, kick me! I'm an idiot. I forgot...

:(

(It's Christmas and all kinds of stuff is goin' on...)

ken cummings 12-20-05 10:53 PM

Hi, About an idea I have not seen elsewhere in this thread which you first posted. Searching under LED truck tail lights I found some massive LED lights that take 650 milliAMPS at 7 to 12 volts. A 7~ watt tail-light? About $45 and $14 for a bracket to support it. They have it in amber, red, and WHITE. Have you or anyone else you know of tried these? These LED arrays are up tp 7" across. A visual angle that large might get more attention than a narrow spot or point. Any ideas? You and SVLOID seem to be the sharp ones on lights.

DCCommuter 12-20-05 11:13 PM

I use Item 1284R on this page: http://www.led-r-us.com/smlights.shtml for a rear light. It's a truck "marker" light with a built-in reflector. It's about as bright as a car taillight, it casts light in all directions (it casts a red pool on the pavement), it's weatherproof, it meets the legal requirement for a reflector, and it runs on my 12V system. Oh, and it was six bucks.

If I recall correctly it's rated at about 1.8 watts.

ken cummings 12-21-05 04:26 AM

Good. I found a different truck supply web sire. Prices about the same. If the light were white would it be strong enough for a headlight? As I understand the physics of an LED chip the light comes out of the edge of the chip with something like a 90 degree spread. That spread is fine for a tail-light. A collimating or lense system is needed if one needs a narrower beam. Laser pointers completely correct the spread to give a very tight beam. Too tight for us. One bike supplier calls their system Opticube; marketing tactic ? :rolleyes: Part of what I like about a six or seven inch wide light emitter is you can get s good amount of light down the road without the painful intensity of n H.I.D. system. Comments?

SpecialKev 12-21-05 11:04 AM

4 Attachment(s)
Just wanted to share some pictures of my 12v light setup. I am using the Optronics driving light housing. A 20w 12 degree spot in the front and the Vellman strobe in the rear. I am using the BatterySpace 4500 aMh NimH battery and easily get over a hour run time. The battery box is a waterproof food storage container. The little black protusion on the clear battery container is a switch. There is a second one on the other side. I also use a helmet mounted 10w spot running on it's own 2000aMh battery that is stored in a side compartment of my hip bag. You can never have too much light :D

Thanks again to all that shared their advice and experience.

Kevin

GlowBoy 12-22-05 03:17 PM

OK, my system is now built, and I rode in with it today. Sorry no pics or beamshots yet, but I'll post them eventually. Meanwhile, here's the lowdown:

- High beam: Philips Masterline 35W MR16, Optronics housing, mounted on front canti stud. $24, 150g.
- Low beam: Luxeon III MR16 (from autolumination.com), Optronics housing (housing drilled out in back to fit the bulb), mounted on front canti stud. $32, 140g.
- Front blinkie: Night-Sun/Lightman Xenon strobe, amber lens, on the handlebar. $40, 140g.
- Running lights: Pirahna 2-LED clearance lights, amber on front fork, red on rear seatstay. $15, 30g.
- Battery: pre-built 12V, 5000mAh NiMH pack (10 "C" cells) from batteryspace.com, fitted into a Zefal Magnum water bottle. 2 external connectors - one always "hot" for charging or high beam, one controlled by a waterproof switch mounted on the bottle cap, just like TurboCat sets them up. $60 (plus $30 charger), total weight 1050g including bottle, wiring, switch, fuse, etc.
- Connectors, switches, misc.: I utilized a number of parts from an old dead "donor" TurboCat system someone gave me. Bonus: TurboCat connectors mate perfectly with the connectors on the strobe, making it plug-n-play. By the way, the "pent" side of the connector is "+" and the "flat" side of the connector is "-".

Until now I have been riding with a 25-watt TurboCat S25 6V headlight system, which is just bright enough for my hilly, poorly lit suburban commute. The Macho SLA battery gives me plenty of runtime, but is also plenty heavy and bulky.

My objectives with this new system were:
- Water bottle battery. The placement of the TurboCat's huge brick makes it a major PITA to carry my bike up 4 flights of train station stairs in the morning. As it turned out, I needed the big Magnum bottle to hold the battery and associated wiring on top, but that's OK.
- Luxeon III based low beam. Low power consumption and still plenty of light for bike paths and moderate-speed offroading I occasionally do on the way home from work.
- Brighter high beam, with more total output and a broader beam than my current spots. And the new system ends up more than doubling the light output of the old one.
- No more weight than my existing system. The S25/Macho weighs 1550g. As it turned, out, the battery+headlight came in at about 1350g, plus 200g for the strobe and running lights. Nice!
- Moderate runtime on high beam. My evening commute is only about an hour, and I only need the high beam on 75% of it. Even assuming only 65% effectiveness due to cold temps and high current drain, 5000mAh should be enough for 45 minutes of high beam and plenty of leftover time on low beam+running lights. Or 6+ hours on low+running lights alone.
- Total cost under $200 for the battery+headlights. I hit that target easily, and the total cost for everything (including miscellaneous parts & supplies) was around $230.

So far I've only taken it out for a quick night ride around the 'hood, plus this morning's commute in broad daylight and a few minutes of demo'ing for curious coworkers. The real test will come in about a few hours. Here are my observations so far:
- Man, that 35W Philips bulb is bright! Even the 20W (spot beam) Philips is just as bright in the center as the full 25W of my TurboCat, but with a substantially broader beam. Impressive, since TurboCats are the best MR11-based systems out there besides Light & Motion. Just goes to show how much better off you are with a high-efficiency MR16. The 35W (narrow flood) is nearly as bright as the 20W Philips spot in the center, with an enormously broader beam. Definitely feels like we're in car-headlight territory. On last night's test ride, I kept looking back to see who was following me.
- The Luxeon III should be fine for low-beam use. This MR16-enclosed emitter is noticeably less bright than my Luxeon III Princeton Tec Apex headlamp, but still far brighter than their Luxeon 1W Eos headlamp. The Apex has much more sophisticated optics than the MR16, so no surprise here. In any event, it still throws quite a bit of light and should work fine for my low-beam purposes.
- The Luxeon III MR16 has a surprisingly well-focused beam, considering that it is specified as 100 degrees. The width of the hot spot is actually comparable the Philips 20W spot, and not much broader than the Apex. It's the spill that appears to go out to about 100 degrees, and while that area is proportionally a bit brighter than with other halogens, it's not excessive at all and there's still plenty of throw.
- The (automotive) LED clearance lights are amazingly bright too, enough to draw attention from any direction even in broad daylight. Well worth the 15g (!) of weight and 500mA of draw that each unit represents. I may put a second amber one on the other side of the fork. Maybe I'll also get myself a much smaller battery for summertime and commute with these babies year-round.
- I believe that the lumen output figures on the widely-quoted Starlight 78 Watts vs. Lumens page are flat-out wrong. I just don't think there is any way that an MR16 halogen is putting out 40+ lumens/Watt at rated voltage (or 50+ when over-voltaged), as claimed on that page I've looked at all the major light manufacturers' product lines, and there is hardly a halogen bulb in ANY format or of any size that puts out more than 15-20 lum/W. Check the Philips catalogue itself: their standard 20W MR16 only puts out 240 lumens, or 12 lum/W, and the super-efficient MasterLine (spot) I have puts out 370 (not 850), which is 18.5 lum/W. Even the 35W puts out 800 lumens, or 23 per watt. Many discussion threads on this board and elsewhere have cited these figures to show that Halogens are vastly more efficient than LEDs and just as efficient as HIDs. I've never been convinced, and the more I look the more it seems that the best Halogens are just as efficient as LEDs, and still not in the same league as HIDs. Don't get me wrong: it looks like my 880 lumen system will outshine many HIDs, but it also consumes an awful lot more juice and needs a much bigger battery.

All in all, thanks again to everyone who has contributed to the ENORMOUS amount of valuable information in this thread. Between this and the Starlight 78 page, I was able to make a huge number of "right" decisions that I might not have made otherwise.

- Dan

DCCommuter 12-22-05 08:26 PM

Dan --

Sounds like a great setup. I like to have a set of lights that has motorists scratching their heads and saying, "What kind of aircraft is trying to land on the road ahead?" and sounds like you've got it.

The MR-16's put out a lot more light than the MR-11's because they have bigger reflectors. The best thing you can do to increase efficiency is to have a big reflector.

Do you have a link for the clearance lights?

mechBgon 12-22-05 10:25 PM

Quote:

Originally Posted by DCCommuter
I use Item 1284R on this page: http://www.led-r-us.com/smlights.shtml for a rear light. It's a truck "marker" light with a built-in reflector. It's about as bright as a car taillight, it casts light in all directions (it casts a red pool on the pavement), it's weatherproof, it meets the legal requirement for a reflector, and it runs on my 12V system. Oh, and it was six bucks.

If I recall correctly it's rated at about 1.8 watts.

DCCommuter, how's the weathertightness on those, pretty decent?

GlowBoy 12-23-05 01:41 AM

Quote:

Originally Posted by DCCommuter
Dan --Do you have a link for the clearance lights?

http://www.pmlights.com/products.cfm...pId=1438#V168A

v168a is amber, v168r is red.

http://www.pmlights.com/cacheimages/...1a5a91872d.jpg

DCCommuter 12-23-05 12:49 PM

Quote:

Originally Posted by mechBgon
DCCommuter, how's the weathertightness on those, pretty decent?

The construction is pretty robust. The light is two pieces, a base and a cover, each piece is solid plastic and there is a neoprene gasket between them. The mounting bolts hold the two pieces together. The elements inside are all "potted" in epoxy, with the hookup wires going into the epoxy as well, so there are no exposed conducting pieces. I would expect it to work underwater even with the cover missing.

They are sold for use on tractor-trailers; the big selling point is that they are more durable than conventional tungsten bulbs. According to the web site they are rated for 100,000 hours (22 years of continuous use).

GlowBoy 12-23-05 03:19 PM

Quote:

Originally Posted by GlowBoy
OK, my system is now built ... Philips Masterline 35W MR16, Luxeon III MR16, Night-Sun/Lightman Xenon strobe, Pirahna 2-LED clearance lights amber & red, 5000mAh NiMH pack ... So far I've only taken it out for a quick night ride around the 'hood, plus this morning's commute in broad daylight and a few minutes of demo'ing for curious coworkers. The real test will come in about a few hours.

Well, now that I've ridden it home, I just have to say I'm thrilled with my system. The 35W high beam casts out an incredible cone of bright light. Too early to gauge driver reaction, but I'm sure the combination of the high beam, the amber running light and the strobe has vastly increased my frontal visibility. And fortunately the battery held out all the way home.

At first I wasn't very impressed at all with the Luxeon III low beam, because it was really only lighting up the pavement in darker areas between streetlights. Then at one point, while riding down a really dark street I noticed a cone of bluish light moving through the trees! So after a quick stop to re-aim the thing so it actually hit the road, it did quite well, casting almost as much light as my old 10W low beam. Sweet!

I got the idea of mounting the lights on the canti studs from this thread, but this decision is causing several problems. (1) The lights end up pretty close to the wheel (unless you seriously mangle the mounting bracket), causing the tire to cast a major shadow and causing a blind spot for oncoming drivers. And that's with the lights hanging down below the canti studs -- if I'd done the opposite it would be even worse, positioning them right next to the tire. (2) Even though I'm using washers, the bolt holding the housings onto the canti studs comes loose way too easily. Maybe I should have put Loctite on the bolt instead of grease! (3) The lights are too hard to remove and put on my other bike.

Finally (4) this location makes for a very serious safety hazard if in the event a light came loose and either rotated sideways into the wheel -- or worse, fell off completely, in which case they would swing down on their wires into the front wheel. I'm paranoid about this: many years ago I had a brake lever come loose and swing down on its cable into the front wheel, causing an instant 25 mph endo onto pavement that I never want to repeat. For this reason, I've always been careful to loop headlight wires over and not under the handlebar, so if they rattled loose they wouldn't fall very far. The Optronics housings will easily bolt onto my TurboCat CNC QR brackets, so I think I'll go that route and position them just under the handlebar.

ken cummings 12-29-05 10:30 PM

From the sublime (post 1021) to the rediculous. No really. In the early 1980s before blinkies and HID lights I converted a steady red tail light to blinking by putting a mercury switch in series with the light. Stopped, the light stayed on. Moving caused the mercury to splash around making and breaking the circuit and causing the light to blink. Now for brake lights . . .

truman 01-10-06 08:56 AM

So, I've got an old 6v Vistalite light body, cables, and a dead, disassembled 4 C-Cell nightstick that I want to repurpose as a 12v, 15-20 watt backup light.

Can I assemble a new battery array of 8 rechargeable C-cells and hope to charge it with the original wall wart recharger, or do I need a different charger?
Do I need more than 8 cells? I generally see 12 volt systems rated around 13.7v, or so, it seems. Or is it because rechargeables are rated lower?
This seems pretty easy and straightforward... what am I forgetting?

DCCommuter 01-10-06 01:22 PM

Quote:

Originally Posted by truman
Can I assemble a new battery array of 8 rechargeable C-cells and hope to charge it with the original wall wart recharger, or do I need a different charger?

You have to match the type of cells to the charger. Also, for NiMH it's really worth it to have a "smart" charger that knows when to shut off -- the cells last longer.

Quote:

Originally Posted by truman
Do I need more than 8 cells? I generally see 12 volt systems rated around 13.7v, or so, it seems. Or is it because rechargeables are rated lower?

The voltage produced by a battery drops as it discharges. For instance, a NiMH cell will produce about 1.4V fully charged and about 1.0V when it is nearly discharged. It will be rated at a nominal 1.2V. So a ten cell pack will be rated at 12V, and will produce somewhat between 10 and 14V in actual usage. In a lighting application it's generally a good idea to "overvolt" and size the pack so that its rated voltage is above the rated voltage of the bulb, so that it provides the full bulb voltage for most of the battery life. So for a 12V light you might use a 11-cell pack (13.2V nominal) or 12-cells (14.4V nominal).

Alkaline cells are rated at a nominal 1.5V so eight of them makes 12V.

truman 01-10-06 04:19 PM

Quote:

Originally Posted by DCCommuter
Alkaline cells are rated at a nominal 1.5V so eight of them makes 12V.

That's where I was messing up... not realizing they were the difference.

Thanks for the help, I'll keep the thread posted with progress.

ken cummings 01-10-06 07:22 PM

Quote:

Originally Posted by truman
So, I've got an old 6v Vistalite light body, cables, and a dead, disassembled 4 C-Cell nightstick that I want to repurpose as a 12v, 15-20 watt backup light.

This seems pretty easy and straightforward... what am I forgetting?

Is the old 6 volt Vistalite light body plastic? What wattage was the old light? If you sharply increase the power in the original body there is a chance you will melt the plastic. I tripled the power in a plastic/rubber headlight body and had no problem, outside, in the snowy winter, as long as I kept moving. The one time I took it inside and turned it on the plastic started to melt. :eek:


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