Welcome, friends of warm, cozy lantern lights
Yesterday I replaced the cold white LEDs of three of my 4x AA lanterns I specifically bought for this purpose (well, to use for myself and for give-away).
As lantern I chose a clone/OEM(?) of the UltraFire ZF6248: http://www.fasttech.com/product/1230501
Welcome to the Litexpress Camp 103: Amazon.de
Very similar, but on US Amazon (but more expensive?): Amazon.com
A little demo of flashlight/lantern usage: https://www.youtube.com/watch?v=PszlrClLuwE
This lantern has a number of advantages:
- very easy to swap the emitter
- relatively small and light
- runs with 4x AA (I use Eneloops)
- can also be used in “flashlight mode”
- blinky mode is hidden, press button 3 seconds from off until it blinks
But where there is light, there must be shadow:
- unregulated driver (this can however be a plus: you can adapt to less light, and you are not surprised by the darkness)
- low mode uses (not too bad) PWM
- with 4 Eneloops it’s relatively heavy: 315g
- LED (on a heatsink) is surrounded by plastic, no heat path to the outside
The text for each image will be under it. So let’s begin!
The first step is to remove the outer diffuser on top. It is a combination of press-fit and rotation, but rotation is hampered by the dry o-ring. You can use your fingernails - if you have strong ones - to avoid scratching it up, or a flat screw driver / knife. Only use moderate force - if it doesn’t pop out, use a different place to apply force.
The inner diffuser also has go. For this, push away the black round element holding it in place (the one with the cables going in). Even less force is needed (and no screwdriver), until the transparent plastic gets loose - press it also to the right to get it out. (the image shows the finished lantern, I forgot to make a photo of this step…)
Now you see the LED mounted on a little heatsink - with no thermal connection to the outside.
Soldering off the LED is very easy even with the heatsink - I think the thermal connection isn’t the best…
Screw off the heatsink, and take it out.
At first I tried to remove the old LED PCB from the heatsink, which is not easy - the glue is mean stuff. :evil:
But there is a very simple solution - just flip the heatsink around! the LED PCB fits perfectly into an empty slot below the heatsink.
Now we can solder on our new precious Remember polarity: white is +. I used some one of five “Cree XP-G2 R5 350LM 2800-3500K” from Fasttech (but you can use cheaper LEDs, like XB-D):
https://www.fasttech.com/p/1921703
And the other cable.
We now have to attach the LED to the heatsink. We can accomplish this with thermal glue, the screws we removed before and thermal paste, or with a thermal glue pad for LEDs. I bought a DINA4 sheet of it a while ago, and now cut pieces from it in the right size and form.
Now its attached and inserted…
And screwed on.
Now is the best moment for a test - and fiat lux! After running 15 minutes, I measure the temperature via infrared thermometer, and the LED case was about 38°C above environment temp. While that’s not really a good value for about one Watt of power, it’s sufficient to not degrade the LED in the long run.
To put the inner diffuser on (not really necessary, but it prevents glare in lantern mode), press the same black round element as in the beginning, and re-insert the diffuser. It has to be inserted from above, not angled, otherwise the plastic noses can’t lock into the right position. After putting the outer diffuser on (see where the noses match the ones on the case), you are finished!
Lets compare tint and brightness: On the left is the original cold blue LED, in the middle the new XP-G2 R5 2800-3500K, and on the right an XP-E P4 with 90+ CRI. The tint comparison photos are shot with daylight white balance.
With less exposure the differences are better to see: the tint is even warmer on the high CRI XP-E, and it much less bright - P4 rank is about 80 Lumens for 350mA, R5 about 139 Lumen. Well, the missing lens and the position relative to the camera are also disadvantageous.
I bought the XP-E at LED-TECH (in Germany):
http://www.led-tech.de/de/High-Power-LEDs-Cree/CREE-XP-Serie/CREE-XP-E-P4-auf-Star-Platine-High-CRI-LT-1754_120_138.html
On the left is the Ultrafire variant (with blinky mode), in the middle our newly modded Litexpress Camp 103, and on the right the old version without the lens in the diffuser, and a high CRI XP-E.
While the lens does it’s job giving more throw, it creates a big dark circle. The white wall photos are shot with tungsten white balance - there is no tint apart from pure warm white visible.
The old version is pure flood.
So there you have it - a simple emitter swap doable in 10 minutes without any special equipment - you only need a soldering iron, a screw driver, and the LED on a small PCB plus attachement method. Have fun turning your lanterns “incandescent-style”