Trustfire based light

[Rockit]

I've been looking to build some canister dive lights. I need to build two because my dive partner is my son.

Use the head and module from this: http://www.kaidomain.com/ProductDetails.aspx?ProductId=10719
I think module is the same as discussed here: https://www.candlepowerforums.com/threads/284903

Plan is to use only the tail cap section, switch removed, epoxied (JB weld) to the head.
Put this http://www.mcmaster.com/#orders/=8598e0 in the switch hole.

Seal the head with O rings and silicone. Build a basic ABS canister and use some 18V battery packs built from these http://www.harborfreight.com/18-volt-replacement-battery-90121.html. Probably just a toggle switch. Maybe reed switch on the light head if I can find one that would fit.

I've built lots of bike lights before, halogen/ni-cad systems. This is my first LED/waterproof build.

Thoughts?

 

[Klem]

OK, I'll comment on the power source...

Firstly, great idea, however you might consider a more efficient power supply. Li-ion power will be smaller, lighter and supply more power/volume than your current idea of using NiCD power drill batteries. Not to mention more cost-effective.

That DX 5-mode Cree torch takes 3 Li-ion batteries and operates between 9.7-18V. The batteries it uses are 18650 size (meaning; 18mm diameter, 65mm long). 18650's come in a range of capacities from 2Ah up to 3Ah. You will need at least two of those bulky 1.2A NiCD Power Drill batteries to equal the glow-time potential of what is designed to go in the handle of that torch.

Just a thought... but these torches often come with a set of batteries and a charger. The specs say it runs for 2 hours on one set of batteries. If that is enough time then you could build your canister to house the three batteries provided. With the cannister being so small you could even attach it to the torch itself either with a super short cable, or no cable and waterproofed some other way as one unit.

Or, if you want more glow-time you could buy a Li-ion battery pack. Any one of these will work;
http://www.batteryspace.com/11.1V-2000mAh---5900mAh-Battery-Modules.aspx

Or, build your own to suit;
6 batteries, plus a protection circuit and plugs H80..W60mm D40mm weighs 300gms... about $30, should give about 3-4hrs glow time.

Or larger. This 3-cell is 10Ah and should give 7-8hrs of light. H80mm W75mm D55mm, Weighs 570gms. 12*18650 batteries and a protection circuit for $50. Even at this size it is still half the size of one of those NiCD power drill batteries.

Just be aware, once you start using 18650 batteries in packs you will need a dedicated Li-ion charger. With individual batteries, you can use the charger provided with the torch.

 

[Rockit]

Or, if you want more glow-time you could buy a Li-ion battery pack. Any one of these will work;
http://www.batteryspace.com/11.1V-2000mAh---5900mAh-Battery-Modules.aspx

Or, build your own to suit;

Good point. I was thinking Ni-Cad because that is what I've used before.

Will the 11.1v give maximum lumen?

I can certainly solder cells together, but at this point I am a bit lost when it comes to circuit protection and charging specifics. I think I need to stick with a ready made pack and charger.

 

[350xfire]

I agree with Klem. Go LiIon and save space and weight. There is no need to go 18 volts. All that will do is create more heat, 11.1= plenty.

As for the light, sounds like a good idea, but I have not done anything with that particular light so I don't know. The reflector LED combo is great though and I would use it in a heart beat for a dive light!!!

Oh, the lens size may be the weak link on that light as it is on a maglite where you have to machine some threads to get a thick enough lens in there... Plus a bigger o-ring.

 

[Rockit]

All right....It's all ordered. I ended up going with 3000mah/11.1V li-po to power them. I'll post up when parts arrive and the build begins.