I am putting high powered LEDs on my bow for bowfishing.
Headlamp style bodies would be great to adjust the light to the align with arrow flight.
I will have a remote battery back under the bussing cable guide rod to offset the front heavy-ness of the fishing reel.
this is going to be intermittent use and I plan to have it switched on by the draw of the bow similar to how drop away rests trigger off the bussing cable.
The boat has some lights but I hope that 1 maybe 2 lights on the bow focused where we are looking will help.
I plan to make my own battery pack and use my own driver(s) but I am open to suggestions. I want the driver to be remote from the lamp to keep the thermal load down on the small headlamp.
I was planning on a XL6019 based boost converter with CC adjustment. I am thinking the 12V option would work well.
I have no desire for a flashing or low setting.
is the XM-L3 available and is it a better option?
thank you and have a good day
So you’re wanting to take the housing off an LED headlamp with an xhp70.2 and mount it to your bow, correct? That could be easy’ish, or really difficult, but I think you’re on the right track by using something already made rather than building it from scratch.
First off, using a standalone boost/buck driver is tricky, since they tend to conk out at around 25W (even though they say 60W output). Trust me, I’ve built a couple light engines based on those running off 3S (12.6v) and they overheat fast at medium output. I just had one die on me last weekend while camping.
You could do something like a momentary switch like they use on rifle lights/weapon lights for activating the light possibly? For the light, I recommend a bicycle-type light, since it already has a mount for a bicycle, I think it could be adapted to fit on a bow. Check out this website for their bike lighting Kaidomain I think they have one with an xhp70.2.
As far as the xml3, nobody’s tested it here, so I don’t know how good they are. They will not be as bright as the xhp70.2 though.
thank you I purchased a complete headlamp with the xhp70.2 and I will evaluate it.
Yes, it will be a momentary switch, each shooting opportunity is about 15 seconds, so thats the longest it will be on. a missed shot takes about 2 minutes to reel in and reload going as fast as possible.
usually its more like 5 minutes between shots, to maybe 15 minutes on a bad night.
but 15 seconds out of 120seconds seems like a low duty cycle. I just need it to turn on to high and not go through a low-medium-high-flash cycle.
I have seen the pencil lead discharging the capacitor to reduce its memory to so short it always comes on high, if high is the first mode.
I had been playing with the idea of series (2) of them to keep the current level modest and drive the voltage up.
is there a blank host for bike lights like flash lights? or maybe a flashlight with minimal tube and the adjustable head/focus piece big enough for the XHP70.2?
If the tube is small enough, it could be used as the attachment piece, which could be nice.
I don’t know of any hosts for bike lights. Usually you buy a cheap one and modify it to suit your needs. Check out Kaidomain for bike lights that are fairly good quality. Otherwise, a flashlight host that can handle an xhp70.2 even at low duty cycle will be large unless you aren’t running it too hard. A Convoy S3 might be a good host for a 70.2, por maybe a M121, bit then again your driver has to be limited to 20mm.
For a driver, I’m using one from Mountain Electronics for a 4S (12 volts) xhp70.2 that is configurable with multiple UIs so you can really customize the outputs. Downside is it’s large…26mm diameter.
What is the typical distance you need to illuminate? What beam characteristics do you want, like beam size and intensity? Like do you want it to be as intense as possible to illuminate fish under the water?
You mention you want an adjustable focus light, meaning it would use a movable lens and not a reflector. This will limit your host options a bit more I think. A focusable lens light (so called zoomie) will also have less side spill than a reflector light. Are these things important to you or would a fixed reflector light work as well?
typically the range is 20’ or less.
The plan is to use a temporary stand to hold the bow, I will then fire an arrow at the ground from my deck to simulate the angle from a boat, and then adjust the beams around where the arrow lands.
on the water I will adjust the “zoomie” to allow me to see 4’ down in the water. the wider area the better, but seeing the target at depth is priority 1,
the boat has some LEDs to allow us to spot the fish, but these lights will allow me to make sure its a carp and not a game fish, along with helping track it as it moves out of the range of the boat lights.
Xhp70.2 might not be the best LED choice since the beam intensity will be much less compared to an XPL HI, which is an LED I would recommend for your application.
I couldn’t really find a standalone zoomie headlamp w/o the battery, but I would think they are out there if you look hard enough, but the quality may be bad. Take a look at a quality 18650 zoomie light like the wowtac A3S which uses an XPL HI.
It is not very heavy, and in any case you are going to have to come up with a solid adjustable mount to the bow. You would have to do some modding to get the switch how you want it. The wowtac has an electronic switch which makes it easier to make it a remote switch, but you would still need to take the light apart.
You could just remove the battery pack. You could swap the LED for a XHP70.2. And if it’s only on for short times you could just connect it to 2x 18650 in series, no driver needed. It would pull between 10 and 18A depending on the wiring and batteries you use.
The drivers designed for flashlights are round to fit inside tubes. For series configuration for a single emitter, they run a buck driver circuit. For a single cell, it’s a boost. The better quality drivers generally don’t have visible pwm, but may use it at lower outputs. Since boost or buck circuits are regulated, output doesn’t decrease as the cell voltage drops (like with fet-based drivers) which is good. Most lights with a single cell with an xhp70.2 are boost drivers. Mtn electronics makes both types of driver, but you can get them from Convoy or Kaidomain in China as well. I have ome of Kaidomains buck drivers running a 6v xhp70.2 from 3S and I like it a lot. Gets hot though so it needs heatsinking.
Depending on how the headlamp bodies are put together you could put a circular driver in each, or you could use an external driver like the one you linked from eBay. Xhp70s are easier to get in 6V configuration. You could plan to use a buck or a boost driver depending on how you configure the LEDs and batteries, and I’m not sure which option is better.
my first blush about this is I would rather run a boost converter and have 12V XHPs in series
I would rather keep the current down given a choice and go with a 24V system.
I could be misunderstanding the advantage of parallel LEDs with lower voltages, but it seems the opposite of how I want to go.
I don’t see how they are paralleled but my understanding is each LED needs to have its own closed loop current control.
I do not plan to have a CC driver and then just solder (2) LEDs in parallel off a single driver and hope the current is shared equally.
Putting multiple LEDs of the same model in parallel is typically not a problem since their forward voltages will be very close. But you can put everything in series as long as you get the 12V configured XHP70.2s. You can get these from US based mtnelectronics.