alternate MC-E driver recommendation

[airsix]

Been lurking for a while and need to ask a favor. I built a 35w HID dive light that I power with a 9ah 11.1v pack. I get a 3hr burn, which is normally enough for a day. I'm going on a trip and will be in the water 7-8hrs per day so the current setup isn't going to cut it.

I'd like to put an MC-E in my spare lighthead and drive it with the 11.1v packs I have. 1/2 the lumens, but tripple the burn time. But I need a driver recommendation. I'm new to LEDs. I was going to buy a driver from George at taskled, but the site is down and another post said he's on vacation for weeks. Can anyone give me a "just as good as George" recommendation for an alternative that I can get in a week or less? Multi-mode would be nice, but efficiency is the biggest criteria.

Thanks in advance for your advice.

-Ben

 

[Packhorse]

Half the lumen? Try a quarter if you are lucky.

Not to mention an unfocused beam.

All sounds like a recipe for disappointment to me.

Anyway I have used this driver before in several projects and they always worked (except the ones that didnt.)

 

[Justin Case]

You can wire the MC-E in 2S2P and drive it with an SOB 1400 if you want to run the LED at the max of 700mA per core. If we assume a conservative 80% driver efficiency, this setup will pull about 1.1A from your 11.1V pack. At 9Ah, that is roughly 8.8 hours of run time.

To order an SOB 1400, you have to get a blank SOB and specify the appropriate sense resistors to give you 1400mA output. You can also order a pre-built SOB 1000 and drive the 2S2P MC-E at 500mA per core.

I would pot the SOB for thermal management.

Another option is the Shark Buck. You could get a 1A, 2A, or 3A Shark Buck. With the 1A, you could go 2S2P as before. With 2A or 3A, you could go 4P. At 3A in 4P, you might get about 7.5 hours run time, so you'd be cutting it a little closer than with the slightly lower powered options. Also, in theory you are slightly overdriving the MC-E at 750mA per core.

 

[airsix]

Half the lumen? Try a quarter if you are lucky.

my 35w hid is rated at 1400 lumen. Driving a MC-E at 700ma per die should output 700+ lumen, right? Hence the "half" expectation.

Not to mention an unfocused beam.

I'll be using a Fraen spot reflector made for the MC-E. Beamshots I've seen look great. But I'm a LED newb. School me if I'm missing important stuff, please.
[/QUOTE]


Thank you both for the responses.
-Ben

 

[Packhorse]

my 35w hid is rated at 1400 lumen. Driving a MC-E at 700ma per die should output 700+ lumen, right? Hence the "half" expectation.

Well your maths isnt bad. But the efficiency of your HID is. Most seem to be 3000 lumen +

 

[airsix]

Well your maths isnt bad. But the efficiency of your HID is. Most seem to be 3000 lumen +

Actually, I was wrong, my HID is rated as 1850 lumen.
I ordered parts last night, so we'll see how it goes. I'll post back with some results & UW beamshots in a few weeks. Thanks again.

-Ben