I have a light with a SST-90 powered by a IMR 265650 cell. On the second day of light usage my Mcclicky Switch failed? I had thought these were pretty much bulletproof? How many approx. amps do you think that I am pulling through this switch? It is a direct drive.
SST-90 Current Draw ?
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Justin Case
Flashlight Enthusiast
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A McClicky is rated at 12V, 4A, 10000 cycles. Clearly, you fed far too much current through the switch.
If you look at the forward current vs forward voltage curve for the SST-90, even at 3.5V the forward current can be about 7A-8A. And if you look at the V-I curve for the BatterySpace IMR26650, at 8A it can hold over 3.5V for about 10 min, easily enough amps to cook your McClicky.
Think about it. You are dealing with something that can pull on the order of 10A. That's house current level. You really want to be smarter than the thing you are working on when dealing with ~10A.
If you look at the forward current vs forward voltage curve for the SST-90, even at 3.5V the forward current can be about 7A-8A. And if you look at the V-I curve for the BatterySpace IMR26650, at 8A it can hold over 3.5V for about 10 min, easily enough amps to cook your McClicky.
Think about it. You are dealing with something that can pull on the order of 10A. That's house current level. You really want to be smarter than the thing you are working on when dealing with ~10A.
irv_usc
Enlightened
Agree with Justin here. You don't even need to measure to know that your switch is fried.
stallion2
Enlightened
i have an SST-90 DD from Nailbender in one of FM's D36/26650 host. FM installed a McClicky for me and i've not had any problems. i really don't know what the draw is though.
Der Wichtel
Enlightened
4A is 4A, you can't go over it
Techjunkie
Enlightened
DigiKey has the 14V 10A Judco switch for ~$2. Maybe you can upgrade your McClicky with that switch?
Chevy-SS
Enlightened
Are you certain this fits? Can you post a link to the switch?
I am putting a SST90 from Nailbender into my P6, so after reading this I may need to upgrade the switch.
Will I be OK using two CR123 primary batteries and the SST90? Or is there too much current draw from the SST90? I will be using short bursts only in this light.
Thanks
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I'm seeing conflicting information here.
I could just be inexperienced, but that switch doesn't look like it was meant to be put in a flashlight, and could take a bit of modding to make it fit.
As someone suggested to me before, I'm thinking the standard McClicky with a spring wire mod would do just fine.
Techjunkie
Enlightened
If the nailbender module that is pulling enough amps to fry the McClickie switch is the only variety offered, then I would not under any circumstances recommend running it from two CR123A primaries...
Yes, it would take a bit of modding to make it fit. I think I've read before that the McClicky is based on a Judco switch of very similar dimensions, and that others have managed to upgrade theirs.
The spring wire mod would lower resistance, yielding higher currents, and kill the switch faster. If anything, the resistance in the tail spring is helping to lower the current drawn through the switch.
Chevy-SS
Enlightened
If the nailbender module that is pulling enough amps to fry the McClickie switch is the only variety offered, then I would not under any circumstances recommend running it from two CR123A primaries...
How can I safely run the SST-90 in my Surefire P6? I have a small lathe and milling machine, so I could easily bore out the body. Sounds like I need bigger battery?
thanks
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Techjunkie
Enlightened
That sounds like a question for nailbender. I assume that an IMR18650 would be an appropriate power source for the SST-90 in a host that size.
flashfiend
Enlightened
My current draw from a 26650 battery is 4 amps at the tail w/ a nb sst-90 in an FM 'C' host w/ McClicky. I will have to say there is some variability in the sst-90 LED Vf and the resistance in the module overall. If your pulling enough current to fry a McClicky you indeed may have a low resistance module. As for battery recommendations, you should know that the AW IMR18650 (16A) can potentially push more current than the BS IMR26650 (10A). So those using the IMR18650 have an even higher chance of frying the switch and/or module with that battery. I know many have said this is dangerous but I don't know if a AW Protected 18650 (5.2A) isn't a better option.
Chevy-SS
Enlightened
flashfiend
Enlightened
I can't say. If you look at my post, I believe every module is different just as every battery is different. I haven't used primaries very much but I think they should be ok current wise because they sag more than Li-Ion's, IIRC.
Sadly, that kind of modding is beyond me.
True enough, I fried my McClicky switch today doing just that. I'm not sure if the SST-90 module itself was damaged by the current or the heat, and I'm not going to find out until I get another one.
Nailbender might not know this, but the inner spring in his module accounts for the mass majority of the resistance. After doing the wire-spring mod on the inner spring, the current jumped from 3 amps to 5 amps.
I probably went overboard by doing the mod on the McClicky switch as well. I read 5 amps on my multimeter, but the test lead wires themselves might have produced resistance so that I only read 5 amps(18 gauge wires, about 2 feet in length). I had stripped two 20 gauge wires and twisted the copper strands together for each spring, making it extra thick. It was likely that the current going through the switch was well above the 5 amps I measured because of the lowered resistance.
Still, I wonder if leaving the McClicky switch unmodded would have resulted in a melted spring.
I'll find out in a few days if running an SST-90 in a 6P using 2x CR123 will fry a McClick running stock.
Ordered the SST-90 drop in last week and just put the McClicky switches in today. Drop-in should be here in 2 days or less. I'm hoping it doesn't fry the drop-in too.
oo:
Ordered the SST-90 drop in last week and just put the McClicky switches in today. Drop-in should be here in 2 days or less. I'm hoping it doesn't fry the drop-in too.
oo:I'd be more concerned about the costs of constantly replacing CR123 cells every 30 minutes when your module completely sucks them dry.I'll find out in a few days if running an SST-90 in a 6P using 2x CR123 will fry a McClick running stock.
Ordered the SST-90 drop in last week and just put the McClicky switches in today. Drop-in should be here in 2 days or less. I'm hoping it doesn't fry the drop-in too.
If anything, I'm pretty sure your McClicky switch would melt before any damage is done to the module. But that depends on how good the heat is transferred away from the drop-in(i.e. how much AS5 you use and where you put it).
