Making Bike lights using the New 900 lumen SSC P7 LED

[EL34]

Thought maybe a few of you would get a kick out of this since it's an electronics/mechanical hobby/project.

I ride mountain bikes at night with lights in the mountians here. Several years ago we all used Halogen lights - Low output, but that's all there was at the time.

Then Came HID's, which I still use, and they make the halogens look like a dim orange flash light.

Now, there's a new breed of LED that is incredibly bright.
In fact it is four separate LED's on one chip, each with it's own gold hookup wires.
The LED asembly is housed under a dome of silicon because of the super high temps at full current draw.

Each Separate LED in the four chip assembly can draw 700 milliamps
They claim you can get 900 lumens at 2.8 amps current.

I have built two of these in the last month,
I am waiting on some 3.6volt lithium Ion batteries to arrive so I can make battery packs for these lights.

Check out my latest bike light projects.
If you look closely at the P7 LED, you can see the four separate LED's under the dome.
http://www.el34world.com/Misc/bike/BikesLights1.htm

[madison]

Are these the ones that make everything look light blue when lit?
If so, I bought a flashlight for around yard with 5 of them in it.
Holy cow, on full (it has a 3 way switch) it's pretty darn bright.
Kind of hard to get used to at first because it's not a spotlight like traditional flashlights.
I thought about strapping it on my scooter for extra light but I am truly afraid I'd blind on coming traffic.
If you look directly into the bulbs, it hurts!

[EL34]

These are white LED's

You probably have some the small round super bright LED's.

I you had five of the P7 LED's, you would need a 3.7volt - 15000 mah battery about the size of 10 AA batteries and it would be so hot you could not hold it. And you would only get one hour burn time from a 15000 mah battery.

Each one of these LED's burns at 2.8 amps!!!
not milliamps

[pullshocks]

Right on.  I have one of the old viewpoint light sets that is just ripe for this conversion.

[LooseChange]

I've got a brand new flashlight with an LED array.  It's bright as heck but the color is weird. It takes some getting used to.

[Ritchie200]

Hey Doug,
How big are those 3.6v Li batteries?  What are you going to use to charge them?  I've got a super bright 130 lumen that eats D alky's for lunch.  The prob I have seen with these super brights is that a slight voltage drop = massive lumen loss.  What are you seeing with this array?
Jim

[EL34]

The 18650 3.6volt Li-Ons are the same ones they use in Laptop computers.
Much Bigger than a AA = 2.66 inches long x .72 inches diameter.
One 18650 will give you about 1 hour of light from a SSC P7 LED.

I solder them together in parallel to create battery packs and get way more burn time.

I sell a simple double 1a chager that works really well
See this page
http://www.hoffmanamps.com/MyStore/catalog/PartsLed.htm




I use fancy didgital display chargers for all my battery packs and single batteries
see this page
http://www.el34world.com/Misc/bike/BikesLights3.htm



I use constant current drivers to supply the LED's
I don't worry about lumen loss because these LED's are so freaking bright, a little loss is not a problem.
These LED can run 700 lumens no problem.
The manufactuer says they are 900 lumens, but everyone doubts that.

See this page for beam shots of different P7 lights
http://www.el34world.com/Misc/bike/BeamShots1.htm

[EL34]

I have one of these SSC P7 flashlights.



You will throw rocks at any 4D Mag light or 130 lumen flashlight after seeing this thing in person.

 You would still need a 18650 battery and a charger.
Free shipping from china, takes about a month.
The price just went down a couple bucks.

http://www.dealextreme.com/details.dx/sku.12325

If you want one, I'll give you the links to the batteries and charger on the same web site.

[Bassmanster]

Great stuff.  I'm showing all this to my cycle nut friends (and myself, ride a single speed conversion Bridgestone).

[Ritchie200]

Thanks Doug - WHAT A COOL SITE!  All sorts of neat stuff like cell phone blockers and jammers  :evil4: :evil4:

I've got a Black Diamond Icon headgear that is listed at 630 lumens at 2 meters.  That thing is too cool with the battery pack on the headband at the back of my head.  I've also got a (something) River flashlight with a 3watt Cree that uses 2 C's and is just as bright as the Black Diamond.  I wonder if there is an accepted lumen test based on a certain distance?

BTW, did you see the (18-20v) 20watt 800 lumen and the 50watt 1700 lumen emitters!!!!!!  They would be neat if you could figure out a way to drive them and keep them cool.

Jim

[EL34]

All sorts of neat stuff like cell phone blockers and jammers

Where the heck are you talking about? 

[DummyLoad]

All sorts of neat stuff like cell phone blockers and jammers

Where the heck are you talking about? 

http://www.dealextreme.com/details.dx/sku.11510

[EL34]

I get it now. 

Yes, they have seem to have a bit of everytying.
Takes about a month to get stuff, but the shipping is free.

[TubeStake]

Hey Doug,
 I was looking at your construction of the Hi-Lo switch regulator. http://www.el34world.com/Misc/bike/BikesLights31.htm In your caption for the photo below, I think you meant to say the notch is at 4:00, not 10:00 for board number 2.

[EL34]

4:00??

That would be on the right side of the board below 3:00.

The photo you posted shows the notch at approx 10:00

Are you looking at a clock from behind?

[TubeStake]

Uh...I don't think I am, not this time anyway. Look again.
Your note that says "notch" is at 10:00, but the notch isn't. The board 2 photo is "upside down" compared to board 1. That puts Ground 2 on the left so the notch must be on the right, at 4 o'clock.

[EL34]

I am looking at the image in you post above that has a big yellow word "notch"

That is 10 o'clock on that image.

The only boards that have notches are the battery board and the switch board.

The current regulator boards don't have notches.

[TubeStake]

 :confused5:

[EL34]

Start from scratch.
exactly what is it you are asking?

[TubeStake]

It's not worth wasting any more of your time with. I was trying to help you fix what I thought was a typo. It would be an easy conversation to have in person but since that's not gonna happen...nevermind (Roseanne Roseannadanna).

I can't wait to put together my first P7 Marwi!

[EL34]

The olnly thing I can think of is that you are looking at that photo and thinking that it has something to do with the 1400ma current limiting boards.

The notch is on the switch and battery boards.

[TubeStake]

Steamboat Willie!

Can we talk about parallel 18650 battery packs? I am aware of the risks involved with Li Ion and the need to solder quick and hot to keep from damaging things. I've read this page which is pretty helpful http://www.technfun.com/soldercells.shtml I'm wondering if you leave the protection circuit attached to each cell and solder them together? Or do you remove the PCB with the protection circuit from each cell before soldering them together, then add one PCB to protect the whole pack?

[EL34]

I left the protection on my packs.
You can strip off the heat shrink and remove them ,but I have not experimented with that.

I wonder if the circuit on each battery affects the current outpu out a little bit?

I may leave the circuits on mine just so I don't over drain them and ruin them.

I solder mine with a 40 watt iron, so far so good doing it that way.
Can't tell if there will be any long term damage from the heat.

[TubeStake]

Have you seen this guy's site? http://www.turboferret.co.uk/background.php He's doing some sophisticated stuff (for a DIY'er) making battery holders for multiple 18650's. I might get a 1S4P holder from him. A little pricey, but when you consider the effort involved with soldering battery packs, modifying a charger, and wondering if all cells are working to full potential, it looks like an attractive option.

[EL34]

Yeah, I am falimiar witn him.

I prefer soldered packs.
No intermittent connections, no dirty connections, etc.

All the batteries discharge and charge at the same rate.

Every 1/10th of one ohm means a voltage drop when you are talkig high current/low voltage applications.

It's hard enough as it is to get the full 2.8amps with soldered connections and big fat connectors like the PowerPoles.

It's easy to get the full 2.8 amps on the bench with direct soldered connections, no switches, no connectors, etc

[TubeStake]

Huh, interesting points...

That might explain why nobody makes them commercially.
Still, I admire people like him (and you) who who can figure out how, and are willing to make these parts on a small scale.

I'm assuming you use 1.4 amps most of the time and save the high beam for fast, downhill, etc. How long does a 3-pack last you?

[EL34]

The 1.4 amp setting is used on the long slow climbs we have here in the mountains.
I actually could use less that 1.4amps, but that's how my two board mod works out.

On the downhills, I like to have as many lights as I can get on.
The older your eyes get, the more light you need

3 P7's on the downhills is what I am shooting for in the fall when I will be doing a bunch of night riding.
Not much night riding going on right now, it's light till 9pm here.

[TubeStake]

Yeah, I want to start with one of your P7's on my helmet and see what it's like, though I'm already tempted to fit a double Marwi to the handlebars. Even one P7 at half power will probably be too bright for commuting from work. I see lots of cars and other cyclists on that route. Don't want to run 'em off the road...

[TubeStake]

Just got done building the current limiter switch stack. Boy, that's small stuff compared to guitar amps! I had to get out the magnifier goggles. Fun, though. I got the stack and the P7 emitter mounted in the heat sink and wired it through my ammeter with clip leads. I don't have any multi-battery packs made up yet so I just used a single 17670 LiIon battery. Low power gave me 1370 mA at the meter. High power showed about 1700 mA which I hope is because that's max current for the single battery. I'm going to dig around in my box of wall warts for a higher current 6v power supply and see what that does.

Doug: it's a very clever design and your parts fit together beautifully. Congratulations.

[TubeStake]

Yup! Higher current supply gave me a 2800mA draw. Can't wait for dark!

[EL34]

Glad it all works.
I noticed that the combined resistiance of battery wires, connectors, solder joints , etc may drop the max down a bit.
Some of mt lights opnly see about 2.5 amps, but that is still super bright enough for me.

When I solder stuff up on the bench for a test with short wires and no connectors, I can get the full 2.8amps.

[TubeStake]

Here it is all put together with a 1S4P battery pack. Holy mother of crap, it's BRIGHT! (and I love it). I cracked up my son and his friends last night using it to barbeque. Practically cooked the steak with the lamp! 

Days are getting shorter now, too.

My clicky switch has started getting a little fussy now that I've used it several dozen times. It seems to be binding just a bit on the hole in the battery board. May need to slightly enlarge the hole, though that could be hard now that it's glued together.

What a great light! Absolutely kills everything else I've seen for the money. You just have to be willing to solder at a tenth the scale of a guitar amp.

Thanks Doug, and have a great vacation!

Roger

[EL34]

yeah, they are nice huh?
I am going to be using 3 of them when night riding starts here next month.

I had that switch sticking thing too once.
You can still depress the switch button down and stick the sharp point of an exacto knife down to enlarge the part that is too close to the siwtch.

I'll have to remember to add a note to the assembly page to enlarge that hole before assembling.

enjoy

[PRR]

> the combined resistiance of battery wires, connectors, solder joints , etc may drop the max down a bit.

This is Low voltage High current work.

And efficiency (brighter longer) is precious.

You want to use short fat wires.

One mod is to put the battery AT the lamp, so wire-length is near zero.

With Roger's on-helmet configurtion, that might be a pain in the neck, true. On-handlebar might allow super-short wires, but aiming is different.

[EL34]

Yeah, the wiring has to be done carefully and you have to pay attention to every connection point.

Problem is, in bike lights, you need to get the batteries away from the light so you have to stash the battery pack somewhere.
You don't want a bunch of weight on your helmet.

Battery packs are usually stashed in a back pack, jersey pocket, water bottle cage or strapped to the top tube or to the seat tube.

I am using 18 gauge wire with 15 amp connectors.
Every connector point is critical in high amperage/low voltage type stuff, as PRR said.

[TubeStake]

I settled on 18 ga wire for now, and made it no longer than it needs to be. I wanted to use 16 ga, but that was too large to work with at the lamp head. I decided to use no connectors, since I can remove the batteries from the holder to charge them. Only thing is I can't easily measure the current, but hey, it's plenty bright ya know. I might cut the wire and add connectors close to the lamp head, then use a larger wire to the battery pack. It would be interesting to make a series-parallel battery pack and compare it to the performance of the 4 parallel.

I'll try the xacto knife on the switch.

[pullshocks]

Doug, my son got a last minute invite to race the 24 hours of Moab and needs a lighting system ASAP.    I wonder if you know of an alternate source for the LED?  I would order the rest of the parts from you.

Mark

[EL34]

You can get them here. This place has them
http://www.kaidomain.com/ProductDetails.aspx?ProductId=1778

They charge way more than what I pay wholesale, and so I have to wait for my supplier to ship me my LED's.

I have a bunch of the Marwi lights sitting here waiting for the LED's to arrive
At that point I will have complete Lights, battery packs and chargers ready to sell.

You can do a google search for SSC P7 and see if anyone in the states has them

[EL34]

Mark,
I just got a shipping notice from my P7 source, they shipped all my backorders.
I have a bunch of LED's on the way, but it usually takes over a week or so to receive them.

I should know this, but when is the moab event?

[pullshocks]

October 9, not much time, so I think he's going to have make do with halogens and their extra battery weight.  It will be my Viewpoint/ Marwi's last time out as a halogen -- we'll do the retrofit when he gets back.  Still plenty of Northwest winter night rides after that

[EL34]

yeah, the night riding season is just starting here in NC.
Long time to go till it's over.

Been selling lots of stuff all summer to guys in the Southern hemisphere.
Especially Australia.
Lots of riders down under.