Batteries - making a torch

[portinfer]

Hi
I am interested in building a torch - I noticed that you can buy batteries from hardware shops and thought that that might provide a better solution for freedivers.

Seems like the good umbilical torches are designed for tech divers who want to go down to a billion metres... Slightly over engineered for us freedivers/spearos.

Also the smaller torches are possibly a bit weak. But they have a better more streamlined "in-one" design.

So I thought: get hold of a decent battery and make a torch for spearing/freediving from it.

The rechargeable battery I have saw in the ScrewFix catalogue -

Makita 2.2Ah Ni-Mh 9.6 (£40)


They are for powertools (driver/drills etc) so should be up to the job for a torch - but I know nothing about batteries... If any one can advise on what to look for in a battery I would be grateful (I think I want high Ah and high Voltage and not too heavy etc - the Makita one looks streamlined too).

Next question...bulbs !

Then ...cases.

Cheers
Ed

[uvjagt]

If you need a spearfishing flashlight for caves rocks etc. buy a skylite or omer moonlight, get recharable batteries

If you want, to build a light for night diving, buy a halogen spot at 50 w 12 v. buy 2 batterys that have 9ah, so 18 in total, this vil give you 4 hours of light
make the batteri box of water pipe, and attach it to a scuba harness.
a small cord and make a ligh head, of plastic/aly or buy one from a tech store

[efattah]

The best light I've found (so far) for freediving is the Omer Stardust 50 (rechargeable). The nightrider lights might work well, but are very expensive.

My StarDust 50 cracked (imploded) on a 53m dive, though rated for 100m. However, it comes with a backup face plate, but the batteries & PCB got fried when it flooded. Even though mine 'failed', it was still the best light for freediving ever. Super strong (50W), wide beam, yet very compact, and okay burn time (50 minutes).

You'll have great difficulty making a waterproof case for a home made light. It can be done but in general you'll save money and time just buying a ready made light.

[JasonWelbourne]

Are batteries water/pressure proof in and of themselves?

[efattah]

No battery is waterproof. As far as pressure, most batteries will fail/mailfunction under pressure except for lithium polymer rechargeable cells. Any other battery must be kept at atmospheric pressure (or approximately atmospheric).

NiMH batteries are encased in metal cans, at 35 psi.