I think the parasitic drain may be high. I let it sit for a few days and the battery seemed excessively drained. I’m thinking of tearing into it and checking it before posting my review.
For the shimmering it’s not PWM at least ai can’t see it on camera. I’ll run it through the Opple lightmaster PWM detector. I think it’s an issue somewhere in the electronics or current path. This light has an interesting current path.
Make sure you pull out the usb cover before you push out the driver otherwise it’ll cut it off
Tried to measure current with my clamp meter but it wasn’t giving a reading. Not easy to measure parasitic drain from how the cell is connected. How would you do it?
Thanks for the tip on the cover.
You’d need to break thr current path between the battery and driver board, so cut the negative wire from the cells negative and and bridge it with your DMM in the mA/microamp setting for the parasitic drain, and set your DMM to the 10A setting for the current test. This light doesn’t draw much current so you won’t necessarily need a clamp meter, but you can try it between the black negative wire. Put the clamp on that wire and try it.
Yeah, I knew the method with a DMM, I was just hoping for another method without cutting the wire. I didn’t actually think of measuring the parasitic drain when it was dismantled, I was more focused on why it was flickering. This is something I should have checked in my review.
How about I test this so you don’t have to dismantle it? Actually I might ask 1Lumen if they tested this, their review shouldn’t be far away
I’m reviewing it for 1Lumen so I’m the guy 
and I haven’t tested the parasitic drain yet. I’m dealing with the fact it only holds High for 10 minutes then steps down like 50%. A bit odd behavior. My review will be done today or tomorrow.
If you can test it that would be helpful, but I may do it just to satisfy my curiosity. Maybe. I’m weary of tearing into lights that aren’t easily reassembled 
Ah lol, I was wondering what your blf username was.
How is it odd? It’s just a thermal stepdown at 40°c like many other models, I reset High after 15 min and it only lasted 4 min.
Well, you’d ruin that nice sticker on the tail. I’ll check it later today
Sounds almost too good to be true. I will wait for the reviews about parasitic drain and the inconsistent lower modes, but I am for sure tempted for the price!
Parasitic drain: 38.1 - 41.9 µA it jumps around between this range.
High: 1.76A
Med: 0.96A
Low: 0.66A
I’m going to put this on charge and check that it’s stopping no higher than 4.25v
Charging stops at a very safe 4.184v
Thanks. That’s good news.
:+1: very nice. Thanks for testing the current and the charging. Good to know it doesn’t have high parasitic drain either.
Stepdown to 50%om a light with just 200 lumens is a bit steep is all. Overall pet pleased with the SF2 for $80! 1400+m throw out of a m21A sized light.
With Sofirn SP35 Clip
