1.5A 3-cell is like 2.25A for 2-cell. The SR3800 does 2.55A. Within spec. There is a less well-known SZBOM one which does 1.7A 3-cells, thommy has it.
1.5A 3-cell or 2.25A 2-cell is good. It is still a ~ 20W flashlight, XM-L. Remember, less heat you also get more lumens. There shouldn't be a lot of difference in lumens/lux, absolutely not appreciable in real life usage, it would show up on a lux meter and camera photos within the first 10 seconds though. :)
All the figures above are for full charged 4.2V cells measured before the pretty fast voltage sag from 4.2-4.05V, and further on the sag is on a less acute gradient, check out the battery discharge graphs.
No worries at all! What is important is , how much lumens does it drop due to heat (great impact due to heatsinking/ambient temp etc).
This 3-cell Trustfire is an extreme runtime flashlight which still gives out decent light and not those 0.00002 lumens stuff though they do that for days, in low mode it can literally run for a day. 3 XM-L, lots of lumens per watt.
Like the TK70, it does 20 lumens for 186hrs on 10AH NiMH cells. I wonder why they did not let us do 3 x 32600 5000mAh (mitro measured the KD one at 4.5AH @ 5A discharge), it can do probably 12 days 20 lumens! Wow!
Thanks for the info. Unforunately I can't find my old lumens meter. One thing I like about the design is the fins on the head, they are thin enough and there are more of them than most of this form factor types, seems like they might actually have some radiation benefits rather than just asthetics.
Hopefully someone with a lumens meter can give a prediction on the heat transfer. I am too chicket to leave it on, I have a pyrometer (laser ir thermometer) but if all the heat is being insulated inside it won't tell me anything.
Another thing I like about it is plain old 2200mAH AW's are fine, since there are three batteries it is less punishment on them than the 2 battery versions, as you said using low, the batteries wouldn't need charged again until 24 hrs of use! That is sweet for camping. Makes this a very practical addition. I'm just hoping the thermals and reliability are as good as they look.
Regal, during summer times like this, doing less than 5 mins on high would be a piece of cake for this. Medium is more than enough light for most uses. If you are in winter sub-zero conditions, no issue 30 mins HIGH is a piece of cake. BTW do remember to see if the cells voltage match before discharging, and if you can help it after discharging.
yea I pulled each cell off the charger at the same voltage measured by my fluke, using 3 new AW's so hoping they discharge the same, plan on keeping them as a "set".
Can you measure w/ 2 cells (the skyray is btw 2cell only). That's actually surprising it's only 1.5a w/3 since you wouldn't really expect a buck/boost in a cheap light.