5mm LED battery drainer

[datiLED]

I hate to throw away batteries that have any juice in them at all. Of course, even a weak battery can power an LED if the driver is efficient.

Here is my take on a Joule Thief, that drains my batteries before disposal. The pictures speak for themselves.

 

[Lynx_Arc]

I use several things to drain batteries, I have a dorcy 2AA 40 lumen LED light that will work down to about 1v I can pull the head off and use it like a floodlight, and I use the LED and circuit from a luxeon headlamp wired to a 4AA battery holder and a variable resistor to light my keyboard up that drains them to zero volts using junk nimh to make up to 3 AA/AAAs. 5mm are ok but the focused beam makes them less useful for light output when they dim too much for ceiling bounce.
also a minimag 10mm LED from niteize works down to half a volt I have used them on a single D cell to run for days and days with just a bent paperclip.

 

[datiLED]

I didn't know that the NiteIze board could drain a single cell. I could have picked up a few of those at Home Depot a while back for under $4 each.

I didn't mention that there are magnets on the battery side of the circuit boards. I used conductive epoxy to adhere them to the boards. While it is probably overkill, I also made a PCB for the Joule Thief. I prefer to use SMD coponents, and it made for an easy build.

 

[csshih]

wow, that is some very good work with the pcb and magnets... looks very professional.. interested in selling one?

 

[^^Nova^^]

Or 2? They look wonderfully made. I love the magnet idea.

Cheers,
Nova

 

[Lynx_Arc]

I didn't know that the NiteIze board could drain a single cell. I could have picked up a few of those at Home Depot a while back for under $4 each.

I didn't mention that there are magnets on the battery side of the circuit boards. I used conductive epoxy to adhere them to the boards. While it is probably overkill, I also made a PCB for the Joule Thief. I prefer to use SMD coponents, and it made for an easy build.

I took one and transplanted it into a rayovac keychain light and it works fine off 1AAA.

 

[JimF]

Why is draining a battery completely before disposal so important. I am not being critical. I just don't understand the concept.
Thanks,
Jim

 

[Lynx_Arc]

Why is draining a battery completely before disposal so important. I am not being critical. I just don't understand the concept.
Thanks,
Jim

before the advent of LEDs when batteries hit 1.1v the lights dimmed to unusable levels. There are still some lights and devices that quit working when batteries hit 1.1v or so. at low power levels that can drive an LED for 10-20 or more hours. 9v batteries can run LEDs for a long time as smoke detectors complain when the battery gets below 7v or so. It is fun to drain all the power out of a battery as you cannot do the same with rechargeable batteries.

 

[dom]

It's not so much draining the battery but the light
you get from it.(handy nightlight or for other purpose)

Cheers
Dom

 

[dealgrabber2002]

oh... i like one...

 

[nein166]

That is the nicest joule thief build I've seen so clean and tight
And it tailstands
Blows my Astroboy out of the water

He was a McD toy, Wired him up with the coil under the base.
Magnet to hold a AA on the base. Copper tab under his hand.
Push a button in his back and the arm lifts, release and it clamps the AA
Green LuxIII in the foot, runs for a few days

Could you put together a parts list and maybe a board design?
How about selling kits?

 

[TorchBoy]

Nice work datiLED and nein166.

 

[M@elstrom]

I don't have many primary cells to drain with the exception of the odd CR123a/AA cell, nice work guys very environmentally repsonsible of you (minimizing waste)! :thumbsup:

 

[daf3m]

That is the nicest joule thief build I've seen so clean and tight
And it tailstands
Blows my Astroboy out of the water

He was a McD toy, Wired him up with the coil under the base.
Magnet to hold a AA on the base. Copper tab under his hand.
Push a button in his back and the arm lifts, release and it clamps the AA
Green LuxIII in the foot, runs for a few days

Could you put together a parts list and maybe a board design?
How about selling kits?

cool!!!!!

 

[datiLED]

Or 2? They look wonderfully made. I love the magnet idea.

Cheers,
Nova

Thanks. I have made dozens of different LED boards, but this was my first design with the magnets. This is actually the Supercharged Joule Thief (high efficiency version) from a cool electronics e-blog site.

Why is draining a battery completely before disposal so important. I am not being critical. I just don't understand the concept.
Thanks,
Jim

It is mostly just me being OCD. I hate to throw out half dead batteries. But, it is also a good opportulity for me to make little gadgets to produce light. I love designing, etching and building circuit boards for LED drivers (and guitar effects). So when I see a cool circuit that I think would be a good build, I draw a PCB in AutoCAD, make a transfer, etch it and make a prototype. If it works, then I refine the design until I am happy with it. If not, then I find out what I did wrong. So basically, it is a hobby for me.

oh... i like one...

I might make a few to sell, to cover the cost of the conductive epoxy and other parts that I had to buy.

That is the nicest joule thief build I've seen so clean and tight
And it tailstands
Blows my Astroboy out of the water

He was a McD toy, Wired him up with the coil under the base.
Magnet to hold a AA on the base. Copper tab under his hand.
Push a button in his back and the arm lifts, release and it clamps the AA
Green LuxIII in the foot, runs for a few days

Could you put together a parts list and maybe a board design?
How about selling kits?

I love your Astroboy! That is really cool. :thumbsup:

Making a kit would be fairly easy. But, the circuit is built with SMT components, and requires a fine tip soldering station, or iron. I have the board documentation ready to go, and a clearly labeled blow-up of the populated board (which makes it easy for me to build). The inductor is wound by hand, and the polarity must be correct for the circuit to work. I could do a kit form of the thing for just a little over my cost. I had to buy the parts to make about 20, or 25 of them just so that I could make the one that you see in this thread. :shakehead

Nice work datiLED and nein166.

Thank you. I agree... Astroboy is cool.

 

[nein166]

That Conductive epoxy is interesting stuff, but what we need are electroplated steel retaining clips that can be soldered to a PCB and hold the magnets.
Astroboy was a fun weekend project that I made, like you said hand wound coil and I just used discrete components and dead-bugged them together. I salvage components off of PC (and Mac) mainboards (great source for toroids), and other garbage.

 

[maxspeeds]

This is a really cool design. I especially love the magnets so that various battery sizes can be used.

If you decide to make more to sell, please shoot me a PM. I'm definitely interested . I also try not to throw away batteries with any juice as I'm OCD about wasting everything from water to household electricity.

 

[dealgrabber2002]

Please let me know when you have a few to sell.

I wonder what's the runtime like on a fresh alky, any idea?

 

[datiLED]

I wonder what's the runtime like on a fresh alky, any idea?

Days. I got 3+ days from a partially used alkaline cell (1.2V). It wouldn't work in my digital camera, but worked very well with the LED driver.

 

[Lynx_Arc]

I just took a 9v battery drainer and hooked it to two 9v batteries I have drained in series to drain them some more.