a flat 5w Luxeon flashlight

[Pook]

This might be a little late - but its the first time ive seen this thread...

Im still pretty new here (and i'm only just figuring out what on earth you guys are talking about half the time with all the abrviations

However I build & fly RC electric planes - so I know more than anyone should ever want to know about batteries.... haha

The batteries you have in this light are not the best choice given that you have the sides exposed - there is a posibility that something could poke in the side and pierce the thin plastic covered cell

If youve not seen what happens to a Li-poly cell (Li-ion - in a plastic bag rather than a metal case) when it is mistreated then have a look see at this video (by RC Groups - Member DNA)

http://rchomepage.com/~dna/LipoFire.wmv

This cell was overcharged but the same could be expected from a ruptured cell.

Piers

 

[dcarch8]

This might be a little late - but its the first time ive seen this thread...

The batteries you have in this light are not the best choice given that you have the sides exposed - there is a posibility that something could poke in the side and pierce the thin plastic covered cell

Piers

Absolutely. Agree. I know the danger of li-ion batteries first hand.
As I said, this is only a proto type for me to figure out a few things before I get to make the final thing, to solicite a few suggestions from the experts here on the design, etc.

Thanks for the observation.

dcarch8

 

[greenjeensus]

Yes. Thats the one I used. I split the pack in two, lined them up lengthwise with the Luxeon in the middle.

I bought the batteries from :

$5.95 each, new.

I bought serveral of these flat rechargeables for future replacements and also I want to make a credit card size 5mm led flashlight for my wallet. There are so many dim restaurants that are so dark that you can't read the menu. The keychain ones are useless because the pill batteries are expensive and they don't last. Has anyone done this before?

dcarch8

That's a good price on those flat batteries. Nice project...I'm inspired to start mine!
Glad about the warning, I forgot how unencased Li-ion batteries could short. I took apart a cellphone battery, with pliers, after it had been through the wash.
The controller chip was destroyed, but there was still plenty of juice in the cell, creating sparks and a nasty smelling gas, as I dismembered what appeared to be mylar coated sheets and gel. The inner aluminum case was quite tough.

Those small pill/coin batteries can be cheap if you get 50 or so. I'm just waiting to go in with someone else who has a Photon keychain lite or two. Prices get down somewhere around 50 cents each before shipping.

Did a quick search at digi-key...
http://www.digikey.com/scripts/DkSearch/dksus.dll?Criteria?Ref=10754&Site=US&Cat=31785855

Another source for good thin batteries (maybe too little power?)are closeouts of older cellular LI-ion batteries. Cell carriers design these batteries to fit sometimes only one or two handsets so they can charge a high price $25-50, before the batteries get cloned and the price comes down. When the phones get discontinued, there is often a large surplus of otherwise unusable excellent quality batteries. Maybe a slight degradation in life.
For example I've paid about $5- 8 shipped for fairly thin batteries, in the 5X30X55 mm(3/16x1 x 2"). The good thing, many cellular batteries are a standard 3.6v with chargers readliy available. Is 850mah enough for a good LED Light? The 3/16 includes the case. The smaller mah sizes are much cheaper and thinner. I usually buy the thicker 5/16 1050mah for handset power, but for thiness that would be hard to beat.

Of course those Computer batteries are in a league of their own, being huge and rechargable Excellent idea! Price is even better!

Does anyone else design flashlights based around the supply of cheap surplus computer and cellular batteries?
-
Dave

 

[Christoph]

I have made lights to fit certain batteries before.It's a lot of fun.

C

 

[VidPro]

i like it, now that it is all flat, and i assume still has protection curcuit, your 2mm away from tossing some Lightweight solar cells on and finishing it
leave it to me to complex it.

 

[Illum]

OH YEAH!

THATS HOT!

BEAMSHOTS?

How much is it to make one? [gives me a better idea how much I should expect if in time your going to sell the light]


1: How did you manage to tap a heatsink to the batteries?

2: Whats the current draw on the batts?

 

[Ganp]

Your proto' flat light looks realy great!! :twothumbs

I think the credit-card idea could be a real winner. Looking forward to seeing how it developes.

Ganp.