Need help with my diving canister light project.

Hi all,

My diving canister light project has been slowly coming along. It is at a point (probably do to user error) that several key components need replacing. Instead of going at this piecemeal - as I've been doing - I would like to consider the whole system.

My goal is to have a reasonably bright (minimum 400 lumen) dive light that will last without battery changing for a full day of diving (say 3-4 hours run-time).

I had almost such a light working with a Cree XLM-T6 '1000 lumen' LED, 2 x 18650 LiIon protected cells, a 1.25A driver, and a remote battery canister created from an old Ikelite mini-C flashlight. The only issues were: run-time was too short for a full hour night dive and pre/post light use; the on/off switch was temperamental; light output was good, but not anywhere near full brightness of the LED.

Being the consummate DIYer I decided to make a larger battery canister with a better switch and upgrade the driver to give more current to the LED. Originally the plan was to use 4 x 1.25V NiMH C-cells, but was changed to using 3.7V 18650 LiIon cells since I have 8 of them. Unfortunately when connecting the new battery canister in for the first time I reversed the polarity (briefly) and since the driver wasn't so protected it is probably what took the LED out.

So, this is what I have, have ordered, and need. I would appreciate input. If I'm being stupid please point that out. No particular component is set in stone.

Concerns are:

• are there problems with the 3 parallel battery circuits? If so any easy fixes?
• Driver and LED match. Looks like the driver on order really puts out 2.2-2.6A not the rated 3A. I'd like to get the most out of the LED but don't want to burn it out. Realistically anything over 400 lumens is good, 600-800 better.

Thanks in advance - Cheryl

Battery canister:

• Length of 2" ABS pipe with a glued end cap and a plug/o-ring removable cap that is retained with a threaded ring.
• The plug has an Arco gland and SPST toggle switch and waterproof boot (both from Hector at TLSlights)
• Passed watertight test to >100' depth.

Lighthead

• From a diving flashlight
• Heatsink will hold a standard star/LED
• room for up to 23mm driver board

Battery holder

• holds 3 parallel, 2 x 18650 protected LiIon cells. (8.4 - 7.4V)

Driver

• On order: from DX.com

  128269

  T6 2500~3000mA 3-Mode Regulated LED Driver Circuit Board for DIY Flashlight (4.5~18V)

  USD$ 4.70

LED (need to order) my current thoughts are one of these from DX.com