It’s not super accurate, but it should be good enough to tell you your batteries condition.
For instance the light may flash 4.0 when the battery is in a range of 3.98 to 4.08 or maybe 3.93 to 4.03. It tries to be close, but it can’t be perfect.
If it blinks 4.4 on freshly charged batteries then you have to mentally remember it’s .2 high.
If your flashing your own UI, maybe ToyKeeper can suggest an edit in the code to make your light be closer to accurate.
TK does indeed have a set that can be flashed into the MCU and measurements taken with different voltages of cells, this will flash out the code you need to put in the program to make your specific light more accurate. I don’t use it, She uses it for every build.
I didn’t read the whole thread, but shouldn’t Sofirn use NarsilM v1.2 in the Sofirn Q8?
No, it’s using the same version as always for the last year. Maybe they will switch to a newer version later on.
In my case I like the way it reads my batteries. If cells are 3.7v actual, my Q8 will say 3.6v. Keeps me ahead of the game a little.
Way to go Dale! And excellent choice in emitters. I haven’t kept up with this thread, but my sofirn q8 arrived today and it’s one of my fav stock light under $40. Throws quite far and very bright. The funny thing is, I wanted to see if I can find if anyone posted stock lux numbers and I was browsing this thread and saw your post asking what we think between xhp50 or sst40?
I was gonna reply back after I finish with reading this thread, that I would personally opt for shaved sst40 for throw and high lumens.
Regular sst40 and xhp50 will give lots of lumens but there are lots of soda can lights that can already do this with even more lumens.
But not many or none out there with decent high lumens and throw.
Though I already had emptied my cart, a few days ago I got a message in my mail to “confirm but not pay” my order of the Q8. So I put the Q8 back into the cart and tried to do what they asked. This was the first time to opt for this procedure. At first the suggestions in this forum did not quite look fitting my case, but eventually I managed to get into the next level (we are awaiting your payment). Yesterday I got a noticication in my mail that the price was adjusted!! From then on it went smoothly. So I will be waiting for the postman too.
My late mother always said: I’ll be the first to admit when I’m wrong, but this time I’m right (as always).
Well now it is my turn. I should have listened better to myself, when telling others that you need to have patience in doing business with Chinese sellers (holidays, time-zones, deadlines, etc). In this case I did not have enough patience. I am glad Sofirn did. Thank you, Sofirn.
A short video of the Sofirn Q8 Quad in action with sliced SST-40’s…
interesting…
My Sofirn Q8 flashed the low “batt signal” at 3.22v on my q35s tonight… at about 1/3 power…. 
yeah, not well calibrated. did a full shutdown at 3.13v.
this is an issue. :exclamation:
Actually, that is normal.
At 3,2V, there is a low voltage warning.
At 3V, there is a full low voltage protection cut off.
With the cells sagging under load, it could easily be going down the 3V mark, and then when measuring the voltage, it will be idling voltage, not under load voltage.
Odd because my BFL versions (3) are all on spec with a warning at no more then 3v and shutdown at 2.8v. all 3…. perfectly.
I think NarsilM v1.0 is 3v warning and 2.8v shut down. If it shuts down a bit sooner I don’t think I would call it an “issue”. The batteries are still virtually dead. I usually recharge at 3.6v or 3.7v.
Do you typically run the batteries down real low?
I have not checked mine yet, but anything in the 3.2 V - 3.1 V range is OK with me. The batteries are about shot then anyway. Lower would not bother me either… the 3.0 V - 2.8 V would be fine too.
In most instances I am going to recharge them before they hit LVP anyway.
I don't know what q35s batteries are but here's the discharge curve of 30Q batteries (taken from HKJ's test):
/Samsung%20INR18650-30Q%203000mAh%20(Pink)-Capacity.png)
At 3.22V resting voltage (=comparable to 0.2A discharge), there is 11% energy leftover in the battery (if you take HKJ's safe 2.8V as empty) , at shutdown 8%. The Q8 draws about 4-5A per battery, so at that discharge state the voltage under load is about 0.12V lower than the resting voltage, so 3.1 V in your Q8 at LVP-stepdown, which is a littlebit too high but nothing alarming, not much left in the battery anyway.
cant believe I missed this one
Riddle me this. My BLF Q8 tube works on both heads but my Sofirn tube only works on the Sofirn head.
My Q8 has been modded. Screws, bypass, Anduril, LEDs.
Any ideas what would cause this?
Tried two diff button tops. Indicator LED does not turn on.
DB Custom, Thank you for the video! That tint isn't too far off from the XP-L HI, at least as far as I can tell.
Possibly the o-ring. It might be preventing the tube from screwing all the way in so it touches the driver.
Or the throw of the threaded end is shorter, not allowing the ground contact to be made. Sometimes lights are like that, many lights you can’t flip the battery tube around for example.
the O ring on the Sofirn is in a slightly different place and it looks like in order to make that tube fit they removed a thread from the inside of the Sofirn head. You can see an entire extra row of threads in the BLF Q8 head