DIY highly efficient, portable and long-living LED lamp

[RolandK]

Hi,

i`m new here and i`d like to share some thoughts on building a portable, long-lasting (lighting time), long-living (battery life) and highly efficient led lamp. Maybe i add a solar charger later on. I chose single-cell setup for easier charging (no balancing needed) and maybe it`s also better for efficiency if difference between led and battery voltage is low. the battery has aluminium case, so depending on the heat produced by the led and electronics, it may be used as heat sink. (if heat is little enough).

Cost should stay below 100 euros.

I have searched a little bit and would consider using the following components.

Battery:
http://shop.i-tecc.de/lifepo4-akku-wina-10ah-3-2v.html
19,50 €

LEDs:
http://www.leds.de/High-Power-LEDs/Nichia-High-Power-LEDs/Nichia-NFSW385A-31lm-weiss.html
0,99 €/Stk
soldered in parallel, not sure yet how many i use.

Constant current source:
https://pcb-components.de/led-aufwa...senser-v2-r-2-200-1350ma-2-6v-18v-detail.html
25,95 €

Switch/dimmer:
https://pcb-components.de/led-dimmer-module/dim-super-miniatur-pwm-dimmer-3v-30v-detail.html
14,95 €

Maybe someone has already done such a project before and wants to give a comment what´s good or what`s bad or if that won`t work and why. There`s always room for improvement

regards
Roland

ps:
these are all components from german shops, if i should translate anything for better understanding please let me know.

 

[DIWdiver]

Those components should all work, though I didn't check that the PWM output of the dimmer is compatible with the input of the driver.

You'll want to run at least two LEDs in series, then run strings in parallel, because the output voltage of the driver must be higher than the battery voltage.

Depending on how you mount the LEDs and how much current you put through them, you may or may not need a little bit of heatsinking.

Keep in mind that if you dim using PWM, the efficiency stays constant. If you dim by adjusting the driver current, the efficiency goes up.

 

[RolandK]

thanks!