PirateBaker
Newly Enlightened
- Joined
- Mar 5, 2016
- Messages
- 1
Hi, CPF!
I am looking into building/modifying a fishing light for my father. It would be used to illuminate the surface of the sea (at night) to attract european smelt (this apparently works incredibly well). My father wants it to be fairly small, something that can be carried with other fishing supplies, and attachable to an old fishing rod (to be used as a telescoping mount).
The simplest solution would be getting a 18650 LED flashlight and spare batteries. I have offered to give him some old 18650s (harvested from an old laptop battery, so free), but he has his own ideas. He wants to power the light from his 12V SLAs.
I searched around the forum, and came up with these ideas:
1) Get an LED flashlight, remove the battery tube, and run it off the SLA battery through a stepdown (buck) voltage regulator. Simple, but according to efficiency curves, small stepdown regulators regulating 12V to 3.7-4V are only 80% efficient (that seems low. Is that low?).
2) Use a 12V LED, like this one:
https://www.fasttech.com/products/1609/10010823/1924906-cree-mk-r-1200lm-3500k-led-emitter
And a 3-18V driver, like this one:
http://www.dx.com/p/18v-5w-cree-circuit-board-for-flashlights-16-8mm-5-5mm-26110
The driver in the example is 5W, the LED is 12W (so, 1A) (12V LEDs don't seem to come in low power). Would that work? Would the LED work being driven at 410 mA?
3) 12V driver and 3 LEDs in series?
I'm pretty sure any of these would work. My question is, which one would work most efficiently? The smelt are fished throughout the night, you obviously can't recharge batteries on the pier, and you can't just carry a pocket full of charged spares, due to SLAs being big and heavy.
So, any thoughts?
(There's also
4) Convince father that his idea is stupid and he should use a flashlight with my free 18650s
Not ruling that out)
I am looking into building/modifying a fishing light for my father. It would be used to illuminate the surface of the sea (at night) to attract european smelt (this apparently works incredibly well). My father wants it to be fairly small, something that can be carried with other fishing supplies, and attachable to an old fishing rod (to be used as a telescoping mount).
The simplest solution would be getting a 18650 LED flashlight and spare batteries. I have offered to give him some old 18650s (harvested from an old laptop battery, so free), but he has his own ideas. He wants to power the light from his 12V SLAs.
I searched around the forum, and came up with these ideas:
1) Get an LED flashlight, remove the battery tube, and run it off the SLA battery through a stepdown (buck) voltage regulator. Simple, but according to efficiency curves, small stepdown regulators regulating 12V to 3.7-4V are only 80% efficient (that seems low. Is that low?).
2) Use a 12V LED, like this one:
https://www.fasttech.com/products/1609/10010823/1924906-cree-mk-r-1200lm-3500k-led-emitter
And a 3-18V driver, like this one:
http://www.dx.com/p/18v-5w-cree-circuit-board-for-flashlights-16-8mm-5-5mm-26110
The driver in the example is 5W, the LED is 12W (so, 1A) (12V LEDs don't seem to come in low power). Would that work? Would the LED work being driven at 410 mA?
3) 12V driver and 3 LEDs in series?
I'm pretty sure any of these would work. My question is, which one would work most efficiently? The smelt are fished throughout the night, you obviously can't recharge batteries on the pier, and you can't just carry a pocket full of charged spares, due to SLAs being big and heavy.
So, any thoughts?
(There's also
4) Convince father that his idea is stupid and he should use a flashlight with my free 18650s
Not ruling that out)