Outdoor rsz_220820132677-762603

Published on September 2nd, 2013 | by Jules Yap


Camping Jansjo battery powered light


Materials: Jansjo lamp, Li-ion battery, socket, wire

Description: I want to share with you a simple “invention” I made to have a camping Jansjo.

At home I have three lamps JANSJO–. They are powered by a switching power supply. The cable lamp is connected to the 4Vdc power supply by an old type speaker connector (in Italy we call it “Punto-linea” connector).

Within the head, close to the LED chip, the current is adjusted with a special IC (I have opened one head, but I do not remember: I think there are two 340mA regulators in parallel for a total of 680mA) and a voltage of 3.4 V is enough to obtain the maximum intensity.




Having some Lithium cylindrical 3.7V nominal (3 ~ 4.2V according to the actual state of charge) 2.4 Ah cells salvaged from old laptops battery packs (I also use that cells for the flashlight, etc., and charge them with a specific Li-ion charger Soshine SC-S1 V3) I thought it might be suitable for JANSJO.

So I connected a small piece of red and black wire to female speaker connector and the other two ends to a
cell, holding them by a slice of bicycle inner tube. (anyone who repair bicycles has some of them to give). The night between the 14th and the 15th of August we had four hours of great lighting at about no cost in the gazebo at the beach!

Ah … I had also brought the gas lamp, but the light was ridiculous compared to a single JANSJO–! :-)

Have a good camping! :-)

~ Gianluca Giangreco, Roma, Italy


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The Author

Jules Yap

"I am Jules, the engine behind IKEAHackers and the one who keeps this site up and running. My mission is to capture all the wonderful, inspiring, clever hacks and ideas for our much loved IKEA items".

10 Responses to Camping Jansjo battery powered light

  1. Tony Snyder says:

    I found this article and its comments interesting. I’ve recently come into possession of one of these lamps without the power supply. I wish the author would have shown a picture of of the connector and shown what pin should be positive and which negative. Where can you obtain the speaker connector adapter. That is a helpful device. And, regarding using multiple batteries for longer life, connect the batteries in parallel. That will keep the voltage into the light at 3.8 or thereabouts, and yield the longer life you want. A series hookup will up the voltage and yield some life length, but also lots of waste heat in the regulators. Those regulators, especially if they are linear regulators, bleed off voltage by dissipating energy as waste heat. I’d be interested in trying the USB powered unit, but I’d be willing to bet those aren’t the same powerful LEDs as the ones powered by the mains plug in supplies.

  2. lawrie hutch says:

    Can you remember the chips that are used to to regulate the current? I would like to work out the possible input voltage range I could use (i.e possibly x2 18650 in series) to extend battery life

  3. Georgia says:

    If you need a handy camping light, you could also buy the Jansjö USB Led-light, and plug it in a Smartphone Portable Charger (USB-outlet).

  4. Arie says:

    You wrote you opened up one head of the Jansjo lamp. Is it possible to close it again neatly or will it get damaged and not close again?
    Could you describe how to do this?

    I also did some transformation of three Jansjo lights, but probably broke something, so I’d like to check the led inside the head.

    • Gianluca says:

      It have been a bit tricky. If I remember, I opened the head screwing in the little space a very sharp screw. Paint is tough, I damaged it only a bit.

  5. Gord says:

    Any ideas on converting the light to run off a 12V connection? ie an automotive battery.

  6. Anonymous says:

    Well done!

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