Tips/Suggestions - WATERPROOF 532nm build (PICTURES ADDED 10.15.2014)

In addition to building laser pointers, I am also a scuba diver. I am interested in building a laser pointer to take underwater (anywhere from 15-130 ft saltwater) to use to point out things to my dive buddy, etc.

I have a good quality underwater flashlight housing that I would like to use for the build. The light uses 4 x AA batteries currently. The light is the one included in *this accessory package on a dive website*.

I have confirmed that the beam of my 532nm 150mw laser (currently running on 1 x 18650 in a C6 host) is not affected by the lens of the flashlight.

I have a few questions:

1. What would you guys recommend in terms of drivers if I wanted to keep the stock 4 x AA batteries? The batteries are wired in series providing 4 x 1.5V = 6V total.

2. The battery does not have a clicky switch. Instead, the lens assembly screws down onto the body of the light, compressing the drop-in module and creating the connection. Can I make use of this same connection system?

3. I'll probably end up sending the host to someone here on the forum to custom machine a heatsink. Any takers?

4. Any concerns about heat dissipation? Would runtime be the same as above water, or would I be able to run the laser longer due to the thermoconductivity of water?

Any other thoughts or things I haven't considered would be appreciated as well. Thanks as usual.

Re: Tips/Suggestions - WATERPROOF 532nm build

most green modules run ~3V so you could use the same batter compartment with 2 dummy cells and get the 3V out of the 2 real cells, like eneloops. With good heatsinking run times should be infinite under water, or at least way better, since its a water cooling system As far as the connection goes, you can create a makeshift switch that emulates the connection made when the cap is screwed in on the drop in. Pics would help.

Re: Tips/Suggestions - WATERPROOF 532nm build

bdgreenb said:

most green modules run ~3V so you could use the same batter compartment with 2 dummy cells and get the 3V out of the 2 real cells, like eneloops. With good heatsinking run times should be infinite under water, or at least way better, since its a water cooling system As far as the connection goes, you can create a makeshift switch that emulates the connection made when the cap is screwed in on the drop in. Pics would help.

Click to expand...

'Dummy' batteries seem like a good idea. What kind of life do you think I could expect out of 2x 1.5v AA eneloop batteries in this scenario? I'd really like minimum 1.5 hrs.

Infinite runtime would be awesome. In reality, I'll probably use it for no more than 30sec to 1min at a time, I think.

How would you go about making the makeshift switch?

Here is a link to an imgur album with lots of pics: Waterproof Flashlight - Imgur

I think what I really need is someone to design and fabricate a heatsink/custom module that can close a circuit when the head is screwed down and open the circuit when the head is unscrewed, even though the entire host is made from plastic.

Any more thoughts would be GREATLY appreciated.