new custom biuld (4xMC-E/3000lm)

[mr ferret]

greetings people, i have been browsing and digesting the welth of info on this forum for which i am constantly amazed at the high level of knowledge and invention here!

Right so about my planned new project. i'm not a diver though i know a fair few but i have put this here as i use dive lights now for lighting and my requirements are so smiler it seemed the best place to discuss it. i'm an underground photographer and use my lights for 'painting' my images, these like dive lights need to be waterproof though only to couple of metres, very sturdy and rugged in construction and resistant to grit and dirt and take a far amount of punishment. i do however unlike most divers require the lights for less running time but at the high brightness and beam focus and need them to be as light as possible weight wise:

The hoped for spec of new light build:

1. one maximum brightness mode (3000lm +)
2. super focus with as tight spot as possible at distance and maximum throw/minimum flood
3. run time of an hour is all that is needed but hopping for more, light is only used for a few mins for each shot so this would be ok
4. battery pack that can be changed in dirty wet conditions without issue
5. high spec waterproof casing which stays cool and resists all you can throw at it

ok so that's what i need so how am i hopping to do it?....

1. useing 4x cree MC-E LED's mounted on one board from led-tech: http://www.led-tech.de/en/High-Powe...x-CREE-MC-E-on-round-PCB-LT-1679_120_117.html
2. this would be run using a simple but efficient 2.8A constant current driver such as hipflex at 14v
3. optic are a tricky one and advice would be useful but looking at using 4 of these from cutter: http://www.cutter.com.au/proddetail.php?prod=cut857
4. battery set up i'm looking at using is 4X 2600mah 18650 li-ion cells wired in series to give 14.8v and capacity of cells ie: 2600mah , having one protection pcb so they can be charged as one unit and potted in high density rubber (what are peoples thoughts on balance charging the whole pack?)
5. being from a mechanical engineering background this would not seem to be a major issue. making the pack as a potted rubber module that slides into recess to connect with two pins inside would seem the best option
6. probably a milled and turned copper heatsink inside a tempted PTFE casing made to size and a hardened and coated glass bezel to the front

so what do people think?
mainly after advice on battery configuration and optics but all thoughts gratefully received
cheers
ferret

 

[Air_Addict]

Ferret

Have a look at the L332MC as a possible option to give you 3000+ lm in a package see link http://www.lux-rc.com/view.php?p=content/showcase/light_engines Please note you can order these unit pre wired, you'll see what I mean when you look at the size of them !!

If you use 3 of these units within one pakage you can get them within a diameter of 48mm ie much the same as the setup your looking at.

LUX RC also do a 16 deg FWHM optic that fits the LEDs

I'm currently building a diving light using this setup and have it all powered up on the bench ready for installation into a housing ( yet to be built !)

On the battery side I'm using 2 off 7.4v LiPo cells from hobbyking.com in a 2S4P configuration to give me 10000ma capacity, this should give me a burn time of 2 hours at full power !!! only tested for 1 hour to date.

 

[2stardiver]

I did build dive light also with this ledtechs 4x mce with ledtechs slim constant current 2.8A driver,
I use batteries 2s 7.2V Nimh which should be 5300mAh but chinese seller sold crap and it takes only 2300-2500mAh so it lights up about 45min
lens is DX's sku.1915
unfortunately I havent yet dive with this.

And I have started to build my second dive light with ledtechs 7up and ledsenser v2 driver (maybe at 1,35amps)
http://pcb-components.de/index.php?...n=com_virtuemart&Itemid=64&vmcchk=1&Itemid=64

going to move those nimh batterys to 7up to get better dive time with that...

 

[lucca brassi]

http://www.lux-rc.com/view.php?p=content/showcase/light_engines

http://www.lux-rc.com/view.php?p=con.../light_engines

http://www.lux-rc.com/view.php?p=content/showcase/light_engines

nice modules driver on star PCB.... nice option for backup (added to driver list )

 

[mr ferret]

hmm the LC modules seem very pricey for what they are thanks but i have reassessed my build from some further research and talking to few people.

not going to use 4 individual MC-E's from cutter as these are cheaper and i can fit bigger tighter optics. these will most likely now be ledil 5.5 degree ones from farnell (CA10861_iris) due to them being cheaper and apparently better to boot!
also probably going to use too 5A bin and two WG bin LEDS to have better color rendition.

battery pack are still not worked out.
4X 18650 li-ion 2600mah cell still seems good plan but thinking wiring 2p2s now to give 7.4/52ah pack, problem is i really did not want to shell out for balance charger

 

[Klem]

With your planned high 'C' rate power draw relative to battery capacity (internal resistance) you'd soon end up having to balance your cells anyway...regardless of the cell configuration.

A balance charger is a handy piece of kit to have around, and the 'cheap and cheerful' EBay-type are not that expensive.

 

[mr ferret]

any recommendations on a fairly good one that won't break the bank?

 

[Klem]

Get onto DX or EBay, type in 'Balance charger' and take your pick. They're all around $40. Something with an LCD screen that will give you far more information than blinking LEDs (most come with an LCD anyway).

I've only ever owned one so I can't really comment on different brands. Some no-name Chinese brand called 'JR 1100'. Works, and is accurate.

 

[lucca brassi]

friends recomended ( firmware upgradable - (they have own forum , they wrote whishes and manufacturer made new firmware), very good electronics (very good electrolyte capacitors- low ESR ) , software ) these

iCharger 106B-plus 250W 6s Balance/Charger

iCharger 1010B+ 300W 10s Balance/Charger

iCharger 208B 350W 8s Balance/Charger

basicaly are the same , they have different final currents -final output ( if you charge some scooter too ... )

 

[Klem]

Lucca,

Been checking out the light engines on Lux-RC and it looks like Serge has one as well...
http://www.lux-rc.com/view.php?p=content/magazine/L332_run_times
He's pixelated out the brand name in the photo but it's obviously an iCharger.

At $80 each you'd expect it to be something special!

 

[lucca brassi]

I have that one ...not so powerful as iChargers ( but I have no time to wait whole month to get it from China )

http://www.modellhobby.de/Electroni...nId=&a=article&ProdNr=0118561&t=130&c=26&p=26

I get it on eBay.de for 106 € but with total post 30€ and package 6€ . After-all it is worth of money. I like charging-discharging over computer, and to be sure about energy realy stored in batteries.

my charger have true USB port for aquisition data of charging , but many ''no brand chargers'' have USB connector but only for charging over USB like mobile phones , bluetooth gadgets or similar so be carefull if you want that option!