The Battery And A Joule Thief

An idea I have had about how to get that last bit of usable power from the battery

[SNikolaM]

Joule thieves are rather useful indeed. Recently, I was asked to come up with couple of ideas for sort of unusual business card. One of them was pcb with smd joule thief circuit on it that had a tiny Al-air battery integrated on it. Current collector on air side was just a pcb copper segment I electroplated with Ni. Al side is exchangeable tab made from soda can. It works pretty nicely, you just have to refresh electrolyte from time to time. And Al tab. Of course, since we're talking about very small currents there, I used capacitor in front of typical joule thief circuit to store some charge before releasing it. Consequently, LED is not lit at all times, instead it blinks every 10-15s.

[Karabetter]

A Joule Thief is a proven circuit to squeeze every last bit of energy out of a primary battery. But is that a good concept when mated with a rechargeable battery? Many rechargeable battery designs have their lifespan and usable energy storage capacity greatly reduced after they are totally discharged. However, using it with a super-capacitor might be useful. :)

[niji]

I like the idea of an e-cig kickstarter. Vapor products tend to be very hard on batteries. The advanced ones draw a lot of power, and the resistance of the heating coils is very low - often below 1 ohm.

[RWBHere]

I use Joule thief circuits for single cell LED night lights and flash lamps. Every clock/torch cell here ends it's life doing that job, and each AA or larger cell runs a small white LED all night for between a few days and several months. The circuit isn't the most efficient, varying across the supply range, depending upon component choices. But who really cares if otherwise useless cells are being used? Their beauty lies in their low cost and simplicity; one transistor, one resistor, one inductor and an LED. Construction time is a few minutes, and they always seem to work. I don't even bother with a circuit board, because they can be built around the cell holder. Supposedly discharged cells (which usually still deliver around 0.9V) will provide useful power right down to around 100mV if a Germanium transistor is used, and certainly less than half a Volt with Silicon transistors. Big Clive's design (which is the one I use) can be found by searching his channel for 'Joule Thief'. For the seriously walletly-challenged, family and neighbours are often happy to give their 'flat batteries' to you so that you can 'dispose of them properly'!

[Wavefront]

Flashlight or a powerbank would appeal more to the masses I would think. Integrate a coulomb counter, meter circuit into it with oled display. Solar would also add a selling point, never being dependent on an outlet, and with the longevity of a capacitor, the device could last a lifetime.

[travismoore]

Just an odd bit on a new joule thief I built. It uses a lot of current it would seem. It lights up very brightly with a 47kohm resistor to the base. Just a 20ma 8mm white led is fairly bright. It uses a darlington transistor of 20k hfe to 30khfe. I use a D cell battery and holder. A 3500uf cap and neon tube across the battery. I wound the coil with about 24 to 26 gage wire I think it was copper enameled. Now the bifilar coil is wound on a ferrite rod from an AM radio. I am thinking I need a current limiting diode to 2ma to the base.

[emil.honganmaki]

Nämä todella mielenkiintoisia kokeita. itse kokeillut kaiken moisia kytkentöjä aina oppii jotain yllättävää.

[gerardmelvin]

Great to see the Joule Theif.Oh the adaptation is a great idea.I use a Vape and the battery charging at the moment is a pain . Also the info on the other videos was very helpful.Gez

[ryefly]

totally enjoy your vids and way you explain stuff... I tinker in the bedini ssg field, would be neat to see a couple of your batterys on these machines.

[Ecoinventions]

You see these E-Cig batteries catching fire on the news all the time, they forget to turn off the units and stick them in their pockets and the button gets pressed too long followed by an explosion and people are hurt. I think this would be a huge market these E-cigs are everywhere. A safe battery would take over the market fast.

[BushImports]

I was just thinking about asking you if you guys had tried any of your batteries or supercaps on a joule thief, I guess I got my answer without asking. I managed to finally quit smoking after many many years of being hopelessly addicted to the damned cigarettes with an e-cig and also off the e-cig as well, I wish that craze had happened 35 or more years ago. Has Steve managed to quit smoking or was he just vaping for the enjoyment of it?Thanks for sharing that.

[PsoriasisChannel]

Love you and your message. Keep up the hard work.

[arthurschroeder]

That what I have been using to test my type of batteries. Can run leds for days with them.

[petersloper]

Haha - I've been wondering for the last year or so if you'd ever turn your attentions to e-cig batteries, Robert. Could be a winner!

[CoffeeandCancerStix]

So I don't understand some of the science but what I'm understanding is you want to make a faster charging battery that won't blow a hole in my leg?

[PeterScargill]

I presume by Joule thief you could just rip the PCB out of any old cheap Chinese solar light? The chips for those (which need one choke) are around 30p on Ebay...

[planetlimbo]

How would you integrate this for a house power saver.

[rszgeyb]

1. Most joule thiefs are very low power to boost a dead 1.5v battery to light up a low power led that needs more than a 1.5v battery can supply (1.8 to 5v or more).
2. The e-cig device draws 3 to 4 amps at 3.5 to 4.2v (not a light load at all), 10 to 15 watts (high current nichrome heating element, )
3. and li-ion hardly has any energy below 3.5v (definitely not 10W+).
So three strikes against a joule thief for a e-cig application. I am not sure how you missed ALL these points in this application?

[altnrgaccount]

Im not sure a jewel thief is a good idea since most batteries dont like to be drained to the last drop. Any gains might be lost in battery longevity.

[evmocean]

hi robert i had a thought about the e cig, why do you need hold a charge all day when you could make a very small cap for one or two bursts then use kinetic energy in form of vibration to recharge so just walking would provide you with ya puff nicotine and if you are lazy just strap it to a pet throw a ball and let them charge it, wind up is the other option.