[MOD] childhood lantern

When I was a kid in the early 2000’s I got a lantern as a gift from my dad. I used it a lot and would get really frustrated at how fast batteries would dry out. Recently I’ve been learning how to solder and this was one of my first projects. The goal was to make it rechargeable and, if possible, do some kind of led conversion.

The thing is made out of plastic, has some o-rings for water resistance and I remember that in the box it said something about it being able to float in water.


The original lamp still works, it’s a Krypton 4,8v 0.5a.

For the conversion from 4xAA to rechargeable i used a TP4056. It can charge a 18650 and offers protection. It was kinda hard to fit the actual 18650 cell in there, but I managed to use the free space where the switch lies inside. The cell was harvested from an old laptop and it’s a Samsung (2200mAh) .

Even with the cell there, the slide switch still works. I was afraid I would have to replace the switch for something else.

For the led, I found out that old Maglites use the same Krypton bulb. So I ordered a conversion kit for that on aliexpress. I ordered the 3.7-4.2v version. Not 100% happy with it cause i was expecting a warmer led. Still worked fine. I was a little worried about it getting too hot, since the lantern is all plastic. It does get kinda hot but it has not melted anything:

After sometime using it as a bedside lantern, I can say I enjoy the runtime the led gives it. It is also a lot brighter. But I admit that I miss the old bulb’s warm color. Might try to get another led at some point.

Looks good, Nice work!

Welcome to BLF.
Great mod. I love to give things a second life.

Thanks for joining the gang, naul!

A diffuser cap squished onto the bulb, with some tint-film, might get it more to where you want it.

Or if you want to go crazy, you can gut the base from the hotwire bulb, get a 20mm star with the LED of your choice (FT got a bunch of ’em), mount the star on a wider disk of Al sheet, and then use a fixed driver to power it.

Or for simplicity, you can get

https://www.fasttech.com/products/1611/10001840/1133803-universal-star-base-plates-with-350ma-amc7135
https://www.fasttech.com/products/1609/10001249/1103520-1w-90lm-3200k-warm-white-led-emitters-5-pack

and reflow the nice 3200K emitter on the star that has a 350mA 7135 already on it.

Or if you don’t need 5 of each, you can get 1 at a time

https://www.fasttech.com/products/1609/10001864/1134701-generic-1w-led-emitter-with-350ma-amc7135-driver

and whatever else.

Then, it’s just solder the wires to the power source and you’re done.

Now, 2200mAH and 350mA means a runtime of 44/7 or about 6hrs.

Get a panny-B or similar 3400mAH cell, and that’s getting you to 9+ hrs.