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parallel drivers

chipdouglas said:
just a thought. you should simplify and just get a flexdrive v5. i have one @ 1600ma. on a single 18650

michael
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I do have a few extra Flexdrives. But the most I can get them to maxed out is 1460mA and even then you have to deal with a lot of driver heating issues. The idea is to split the load to two drivers to keep them from overheating and also to achieve a current that is not possible with the flexdive.
 





Should try this with flexdrives since they are more efficient on the battery.
 
DTR said:
Ok I got two microboost's today running at 850mA each set up in parallel in my MXDL with a single 18650. It is very bright for about 3 second and then starts flashing. I do not have a fully charged batter here at work with me. When I get home in a few hours I will slap in a fully charged one that I have in the charger right now and see if it works. If it does not I might be on the lookout for a host that can fit two 18500.
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Yes and I tested two Micro BoostDrives in parallel (each set at 900mA's per your request)...

They put out 1740mA's together. It would probably have been 1800mA's for sure but the battery probably couldn't handle the current draw. It was a single AW 18650 battery.

I didn't measure current draw from the battery, but I'll bet it would be near or over 3 Amps...
 
Alright well the battery's just cant handle the draw. It just goes in to protection mode after a second or two. :cryyy:
 
DTR said:
Alright well the battery's just cant handle the draw. It just goes in to protection mode after a second or two. :cryyy:
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What would also work I'm sure, would be two AW 18650 batteries in parallel...

Of course it would be a larger set up...
 
jayrob said:
What would also work I'm sure, would be two AW 18650 batteries in parallel...

Of course it would be a larger set up...
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What I was thinking was a host that could fit two 18500's(I have driven these diodes at 1A just fine with the 18500's). It would not need to be as long as with two 18650's. The AW's are 1500mAh in the 18500 compared to 2200mAh in an 18650. This might be a custom host like an Ehgemus host or something.
 
A size D battery is about 33.1mm in diameter , so you might be able to squeeze two 17670 batteries side by side into a size D host, or maybe even 3 X 17670's in parallel...

But a D battery is about 7mm's shorter than a 17670... Sounds close enough that I'm sure some modification could be done with the right host though...

Edit: How about 3 X 18650's!
http://www.candlepowerforums.com/vb/showthread.php?t=269751

http://cgi.ebay.com/TrustFire-1300Lumens-4M-3-x-18650-SST-50-LED-Flashlight-/150443616079

http://www.lighthound.com/Ultrafire...e-Flashlight--3-x-18650-batteries_p_3617.html
 
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Nice Megallenium host! 1.8W handheld pointer possibly. The LD might fry a little sooner, but for a max bright beam..........
 
Great news. It works.

I set up a very crude experiment. I have two 18650's set in parallel, two microboost's set to 900mA each. Jay measured the output at 1740mA's. It seems to run pretty stable but the drivers still get very hot still. I think they are boosting heavily. Next I will try three 18650's in parallel and see if that keeps them from overheating as fast. I did use a diode that I had previously smoked badly and could not clean the diode window. I did not want to risk a good one but it works just the same.

 
Well, I'm really glad to see it working, and more or less as expected. Though it seems we were wrong about the heat issue, which I find pretty disappointing personally. It may just be time to try to come up with another driver solution.

With the heat and output issues for the v5 (not to mention availability), and the unknown status of the v6, I'm thinking the answer might be a custom driver for these high-output applications. If we can't get heat under control, I'm not sure what there is left to try.
 
I'd really like to see what 2 flexdrives act like at 900ma a piece. Considering they can do 1500ma alone I would think 900ma's would be a cake walk for them.
 
AdamCaudill said:
Well, I'm really glad to see it working, and more or less as expected. Though it seems we were wrong about the heat issue, which I find pretty disappointing personally. It may just be time to try to come up with another driver solution.

With the heat and output issues for the v5 (not to mention availability), and the unknown status of the v6, I'm thinking the answer might be a custom driver for these high-output applications. If we can't get heat under control, I'm not sure what there is left to try.
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The answer might just be to be happy with the Micro Boost at 1075mA's maxed. (give or take 40mA's)

If you try to set the third jumper and go for 1200mA's, there are heat issues. But if you just stick to the two jumpers as shown in the documentation, it seems to be just fine maxed out. Which is around 1075mA's give or take 40 mA's...
 
A 37 second runtime is not much less than the first time I used a flexdrive maxed out at 1.5A without a heatsink. Unfortunately it does not seem as easy to mount a heatsink on these drivers.
 
I wouldn't be too sure it's the drivers that are getting too hot because I know a Micro BoostDrive maxed out at over 1 Amp will be fine for at least 1 minute or more...

Two in parallel shouldn't cause more heat to the drivers. (I don't think anyway) :thinking:

More likely the battery supply cannot handle the current draw...

If you had a power supply you would be able to determine the validity of that theory quickly...
 
jayrob said:
I wouldn't be too sure it's the drivers that are getting too hot because I know a Micro BoostDrive maxed out at over 1 Amp will be fine for at least 1 minute or more...

Two in parallel shouldn't cause more heat to the drivers. (I don't think anyway) :thinking:

More likely the battery supply cannot handle the current draw...

If you had a power supply you would be able to determine the validity of that theory quickly...
Click to expand...

I am actually looking for a good variable power supply with digital readout for around or under $100. Any ideas? I already ordered a labby style heatsink from Flaminpyro.
 
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