*BLF LT1 Lantern Project) (updated Nov,17,2020)

Another photo of the well-tested & beaten prototype with my favorite Rum back on my east coast trip, here in the wilderness with the moon in the sky. ( lantern was on Low mode for this photo)

The 35E x 4 (with 3500mAh) in the Lantern would give amazing run-times even on a 1-amp high mode. (that’s 14 Amp-hours of total capacity!) a single charge of 4 cells would give a long weekends of use easily.

That’s a really great picture, and I bet the rum is tasty too.

im interested in that lantern too.

If it’s a Nx7135 or FET+1 or FET+N+1 linear driver, the driver should be a fairly quick and easy matter since there are already several good designs available. If it needs to be a boost/buck driver, or if it needs USB charging / powerbank functions, you’ll definitely need one of BLF’s overworked and underappreciated circuit designers to help create something new.

There should at least be plenty of room for boost/buck components, especially if it only needs 500 lm.

As long as the driver isn’t too crazy though, I should be able to put together some firmware for it reasonably quickly.

Of course, the easiest lantern solution would be a bezel attachment for the Q8. If that isn’t appealing though, it sounds like there are a variety of other options if people are willing to put in the work.

That’s a VERY interesting concept. Frankly, I haven’t considered a SRK lantern other than a diffuser for Q8.
But add a powerbank with enough power to run a laptop and with replaceable batteries (so I can run it for long) and it’s indeed an interesting concept.

Run a laptop? That’s silly. If you want good efficiency, get a tablet. Those can run 10 to 15 hours on the built in battery.

Yes I wanted to convey that 12v out seems not smart to offer

  1. I find laptops WAY convenient than tablets.
  2. I find a power bank WAY cheaper than tablet. Especially that I have batteries anyway.
  3. 4*35E holds more energy than an average laptop, though there’s conversion loss.
  4. If I use all my high-capacity batteries, I could run an energy-efficient laptop for entire weekend. Or my i7-7700k one for 12 hours. :slight_smile:

You doing business work out in the woods? Lol

If I go camping I want to be left alone, and the quality of the latern and runtime is for me the top priority, the other stuff is nice to have, but if it would impact the quality of the lantern I’d rather do without the other stuff.

Agreed. You are camping, leave the laptop at home and use your phone if you MUST check email (or Facebook if that’s your thing). Or as Jason said, a tablet if you can’t survive for a weekend with “just” a phone screen (but them why are you camping at all?) and as was mentioned, most laptops need 19v anyway, so the point is moot IMO.

Now on the other hand, 12v in seems highly useful, being able to charge the light from a car or 12v solar source adds a lot of functionality.

I think if it is decided to go with 12v out, it should be in the form of a cigarette lighter socket. That means any car adapted devices including usb adaptors, lead lamps, car vacuum cleaners, mini compressors or airbed inflators can be used. Sounds useful but it seems like a bit of a stretch at the same time, a big ask for 4x 18650s, and the potential amp draws make the required components probably a bit chunky and expensive.

Maybe a task for another project, a one-size-fits-all emergency power source, with adaptors for everything and a light for convenience.

no way i can imagine a boost circuit to make the 2.9-4.2V cells deliver 12V would make sense and probably is very expensive
Lets forget about anything other then 5V USB out please.

Definitely agree there. Its just not practical or a good idea at all to put a 12 volt output on a small lantern, especially one that has to be compact as a beer can and have long run times from 4 - 18650 cells in parallel.
a 5 volt USB charging cirsuit is possible, but a 12 volt out, no.

Many power banks have cells in parallel with QC USB output at 12V. Let alone all the single 18650 XHP35 lights.

And all those XHP35 drivers out there?
A single boost driver could deliver 6(?)V to the LEDs, 5V to the USB output and 12V to the 12V output. It would possibly be somewhat more expensive than linear + small boost, but would deliver better efficiency, higher 5V power and 12V (with slightly worse efficiency) on top of that.

[quote=sac02]

Is it really? There are plenty of 12V->USB converters out there…

Great, thanks! (nobody has understanding for the decision of pb anyway)

[quote=Agro]

This is true
And would mean a port less, less electronics so yeah valid IMHO but it is up to DBSAR of course.