Hey there BLF! I finally finished my review of the BLF-348 after they’ve all been sold out. When the group buy was still active I purchased two, which at under $8, was a steal. In the review I test the output, make beamshot comparisons, and do runtime tests. This light holds up just fine to prolonged 10440 use, although it does get a bit hot near the head of the light. Make sure you use a 10440 cell carefully if it isn’t a protected cell, because the light does not seem to have low voltage protection built in for lithium ion batteries. What else… Hmm… it’s under 5 minutes? It’s short and sweet(?), and to the point. Let’s hope the next group buy goes through.
Thanks for another good one! The time and effort you put into these is much appreciated. Here are the data I extracted from the vid.
BLF-348 – Measurements by MHanlen
Battery
Lumens
Candela
Distance
Runtime
Eneloop AAA
48
193
27
1 hour
Efest IMR14400
176
744
54
27 minutes
I could not tell for sure, but I think you were joking about the "thermal regulation" offered when running on Li-ion. I take the flickering to be a sign that the driver is overheated. Component values in the driver are evidently changing as they cyclically heat up and then cool down.
My own choice is not to use Li-ion. I think this light runs too hot on that battery.
I was being serious. I’m making an educated guess based upon a few things. First the brightening and dimming. I’ve done many video runtime tests now, and the only lights I’ve seen do this are ones with thermal regulation. The Noctigon Meteor and the Xtar H3 are examples- and if you watch my video reviews you can see this happen during the runtime test sections. Another piece of evidence: This thread here shows the BLF-348 light being disassembled with a 7135 chip used on the driver.
And this says that 7135 chips have built in thermal regulation.
I might be wrong though, so someone feel free to correct me as to why this isn’t true. Also, one other thing. The light does not have built in low voltage protection, so be careful about running the battery for the full runtime.
Thanks for the great video. I really wasn’t thinking I needed one of these. I think you helped change my mind.
Oh yeah, that copper tool looks sweet! I’ll Check out that video next. 8)
Is the thermal fold-back a self-defense mechanism of the 7135 chip? Is the chip protecting itself from damage? That would be good thing. But how late in the process does the protection kick in? By the time it gets that hot, are other driver or emitter components at risk?
With a stainless steel host, the problem is that once it gets hot it stays hot. It takes a significant amount of time for one to cool down.
I will be reading this thread to learn more. For the time being, however, I will stick with my original decision. The fact of the flicker tells you the BLF 348 runs too hot on Li-ion. It's nice to know that at least the 7135 is trying to protect itself, but that does not make a flickering light any more useful.
As always, the user plays a big part in this. For those in need of brighter output for limited periods of time, there should be no issue with Li-ion. Just remember to turn off your light if you feel it is overheating. For me, that would mean before it starts flickering.
It’s not a flicker. It’s a steady ramping up and down its something you may not notice while you’re using it. Personally, yes the light is kind of small for this sort of heat. I’d use a larger light for prolonged on/off times. But since this is a pocketable EDC light, it’s great for uses ranging a few seconds to a minute or two. I’m more inclined to use an eneloop in the light anyway. I think 40ish lumens in a tiny EDC is more than enough… If I need 170 lumens or more I usually carry a bigger light, with a bigger cell. But this tends to be one of those places that likes to push the limits of what lights should do.
A multi-mode version of this flashlight would be more suited for Li-ion. With lower modes available, you could just change modes when high got too hot.
Yep. But look at the Noctigon Meteor. No light that size can handle 4000-8000 lumens for more than a few minutes. It has thermal regulation built in, because it has to, to protect the light from damaging itself. I don’t know how advanced the 7135 thermal regulation is, but it’s temperature controlled… And I the meteor also gets just as hot to hold too. I also own other lights that get just as hot too handle too. The 348 though is still very holdable even after 10 minutes. But yeah… Less heat equals a longer life to the internal components.
