Joule Thief Battery Charger (Revisited)

This is my latest Modified Joule Thief Battery Charger.
The circuit has been running now for 3 or 4 weeks one dead batteries, swapping the batteries every 2 days.
I also recharged a couple of NON rechargeable batteries without any problem and they are still powering my remote controle.
It will take 2 or 3 sets of 'dead' NON rechargeable batteries to completly recharge a set of NON rechargeable batteries.
So when you think your batteries are empty, try this circuit on and prove the difference.

Last Joule Thief Battery Charger i made was about 2 years ago and i find the joule thief such a interesting circuit i decided to build a new and better circuit.
If anyone is interested in the previous video (including ciruitdiagram) here is the link:
If anyone wants to see the Low Cart Project where i busted up my hand, here is the link to that one:

If you guys (or girls) have any suggestions on how to make this circuit even better or more energy efficiënt then please let me know.
If you have any questions please let me know and i will answer as soon as i possibly can.

Enjoy.

[FluxEnergizer]

@tec
Thank you for the kind words.
I'm happy you like the circuit.

Regards,
Flux 4 Energizer

[FluxEnergizer]

@Rayman King,

Ik wind de inductor gewoon met de hand. Ik gebruik 0, 2mm emoaille draad.
Het hangt er helemaal vanaf wat je met je spoel / inductor wil doen. Soms neem ik 2 draden tegelijkertijd en wind ik ze samen. Soms neem ik 3 afzonderlijke draden (voor schakelingen met een secondaire spoel) en wind ik ze stuk voor stuk.

1 ding is in elk geval zeker, het kost een hoop tijd en geduld.
Suc 6. Als je verder nog vragen hebt hoor ik het wel.

Mvg,
Laurens

[FluxEnergizer]

@acmefixer
That is correct the Joule Thief is acting as the current limiter, that is what i'm explaining in the video. That's why there is no base resistor because the length of the wire or in that case the number of turns on the toroid is used to controle the dc resistance.
I'm sorry but i disagree that a resistor is much simpler then using the coil itself I don't see that point.
Thank you for the reply.

Regards,
Flux4Energizer

[MrFreddiew]

Hi..Replying to this now maybe old video..But I did this following your schematic, but used only 1.5 volt new AA to charge a depleated AA rechargeable. Used 2x 2N3904 transistors and a blue LED as a diode, seems to work fine. Putting 3volts in to charge a rechargeable charges really quick..maybe too quick. Nice and simple circuit. Will be trying Sohei Thoth & emc4u2 circuits next when the bits arrive. Thanks for your excellent video.

[KyleCarrington]

Here's a thought: Add a small solar panel, as I have done. Write a basic program to run a PICAXE do do a bunch of comparitives, have several banks. Sun comes up, PIC chooses a low bank, charges it. Sun goes down, LDR kicks in PIC, PIC chooses a strong bank to run lights. Free energy, with less emphasis on solar panel size, due to numerous banks. If a cloudy day hits, your charging a partially charged bank, and running lights off a fresh bank up to full charge.

[KyleCarrington]

I like it! Works better than my standard JT charger. I want to add a schottkey diode on the input to stop spikes from hitting the solar cell (in place of the charge bat). Maybe a small cap too. Thanks

[wjewell]

i will have to try your circuit design, ive been i little bored with the joule thief but this my friend is really cool

[trailkeeper]

right, because when a bike come to a stop you want the light to be still on usually, i was thinking a capacitor can store a few seconds/minutes.

[haggardhagi]

Blessings, these videos are greatly appreciated, keep it up brethren

[trailkeeper]

The led is a nice indicator that the circuit is working ok, but it is also a waste of power, so maby have a switch to temporarilly turn it on. It the diode action of the led is still needed for the circuit to work properly, then a regular 0.7v diode might be ok. Would this be a good idea?

[FluxEnergizer]

@Trailkeeper,

Okay, i see where you're going.
Yes, you can do a lot of different things with this circuit.
But boosting from any source is possible and storing the energy somewhere is a very good idea.

Regards,

Flux4Energizer

[FluxEnergizer]

Yes, you could use a supercapacitor for storing the energy. It would be able to store a couple of minutes worth of energy.

[FluxEnergizer]

@UrCoffeeTastesToasty

I'm happy the circuit worked for you too.
Thank you for replicating.

Regards,
Flux4Energizer

[acmefixer]

Actually, the Joule Thief is acting as a current limiter to prevent the 3V battery from trying to push a large amount of current through the 1.5V cells The advantages I see are that the JT pulses the current which may have some benefit to charging the cells; and it's possible that the JT may be more efficient than using just a resistor for limiting the current. But the resistor is much, much simpler.

[FluxEnergizer]

@Trailkeeper
You are right, but the Joule Thief circuit (too me) is ment to light a LED (or multiple LED's). So this is what i intended to do: light a LED and feed back the used energy to a set of other batteries and swap them around.
But removing the LED and use a diode instead also works. If you use a 1n4148 or a bat 49 or something like that the voltage drop would only be 0.2 volts.

Thanks for your reply.
Regards,

Flux

[trailkeeper]

Thanks. Ok, I was thinking of like maby boosting the supply voltage from something like a small solar panel or some other low voltage source, to recharge batteries / save -store the energy. I would like to maby make one where its on a bike, and the voltage source might be a magnet and small coil charging up a small capacitor and that voltage running a joule thief. Many ideas to consider.

[KyleCarrington]

@Flux4Energizer last I checked; resistors don't provide back spikes and desulphate cheap throwaway non-rechargeables :) I like the circuit idea. Thanks for sharing.

[FluxEnergizer]

Thank you for replicating.
Please let me know if the diode helps.

Regards,
Flux

[FluxEnergizer]

@harpbloke
Thank you very much.
Good luck with the replication.

Regards,
Flux 4 Energizer

[trailkeeper]

Well, not that I think about it, I'm not sure if its a real waste of power, because with 1 diode, not the led diode, the current through that could be higher, so maby two diodes, just ideas.