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

Add me to the happy LT1 owner list. Love it and use it all of the time. The links earlier in the thread for the shade and base are appreciated as well. The accessories make the lantern more versatile.

While it was myself who got the project started, I have an awesome team and contributors who spent time, and worked to make it a reality, including, ToyKeeper, SIGShooter, Barry0892, DEL, The Miller, Phlogiston, Lexel, sbslider, BlueSwordM, bmengineer, Lux-Perpetua and amishbill. these all deserve the equal credit on this project, ( and future projects we work on.

February,08,2022

( also updated in the main OP Topic post.)

An update on the LT1, and other projects including the LT1M (mini)

  • The pandemic has slowed things down quite a bit, including my big move, lifes-change, etc. But i am still dedicated to new progress on this BLF project with Sofirn for future models, advancements, etc.

While it may have been myself who got the project started a few years back, I do not deserve all the credit in this what so ever… I could not have done this alone at all… And with an awesome team and contributors who spent time and worked to make it a reality, including, ToyKeeper, SIGShooter, Barry0892, DEL, The Miller, Phlogiston, Lexel, sbslider, BlueSwordM, bmengineer, Lux-Perpetua and amishbill.

These all deserve the equal credit on this project, (and future projects we work on.) i wis those who enjoyed this venture and a happy customer of the Sofirn BLF LT1, give them all a great thanks of appreciation. You all are amazing, and valued in this project so much! Along with the family of the BLF community, SB working so much to make this community great, I again thank you all from my heart. – Dennis / DBSARlight

I used this lantern a bit last summer, then left it somewhere on a table.
Today I try to turn it on and won’t turn on. So I take out the batteries and see that 3 of them are discharged downto 2.3V and one is at 3.7V.
I’m not sure if this is normal or not, but I thought I should post about it.
It seems that it self-discharges quite a lot when not in use, and not evenly.

Are you using button tops, or flat tops with solder blob?

Flat top batteries.

button tops will fix your issue, flat tops don’t make a good enough connection

That is very unusual, as all four of the cells are held in parallel, thus they can only discharge or charge all at the same rate. There must be some issue with the cells not contacting the top ring, (as flat-top cells would cause that and not recommended.) even then the cells should never self-discharge at that rate unevenly unless the cells are defective.

A friend had a similar situation but he had 1 battery below 2v with the other 3 above 3.8v. He also hadn’t used it in over a year and like Kat’s it wouldn’t turn on.

It’s interesting that his light as well as Kat’s wouldn’t turn on with at least 1 battery > 3.7v given that the LT only needs 1 battery to run. Unless as you say that they weren’t making contact with the ring for some reason.

If I get a chance I’ll look at his light and batteries. Could be that he’s using flat-tops where contact with the ring can be hit-or-miss depending on the brand.

He was using old laptop batteries which could account for the 1 cell reading so low. As I understand it drain from the switch is minimal and shouldn’t draw much from even a single battery over the course of a year.

I am using flat top Samsung 30Q with solder blobs added and have no issues with LT1, a least time I checked, I will check them next time I remember on a meter to see if they are all parallel.

Laptop batteries usually have lived a hard life and I find can fail at random, good for low cost projects through where that is less of a concern.

For those interested, Sofirn’s AliExpress shop has a sale coming up in 10 hours for the LT1 with batteries at CAD $75 or USD$60. https://www.aliexpress.com/item/4000238008009.html Same price for black, green, or orange.

Nice deal!

Red… Why no red?!?

I still have just the old LT1 prototype, but it gets used every night and I only have to charge it once or maybe twice per year. It’s a pre-production design with a different shape for the top and the handle, and a different layout for the LEDs, so the alternating warm and cool LEDs are visible inside.

I think the batteries I’ve been using lately are a set of 4 Sofirn cells. Haven’t opened it to look in ages, since I don’t need to open it to charge it.

At some point, I hope to get a newer model. I think Sofirn might be updating the driver to use an attiny1616 chip instead of attiny85, so perhaps I can get another dev unit for updating the firmware. If that happens, I’ll probably enable thermal regulation, because there’s room to spare, and because it could be useful for a future version of the LT1-mini. If I recall correctly, the mini has the LEDs close enough to sense temperature.

If they do this, I hope they take the opportunity to add a red channel.

And if they send you a dev unit, I’d suggest the red channel could be handled by pausing during tint ramp with a brief flash at 100% warm. If the user releases, stay at that tint. If they keep holding, start mixing warm and red. If they release and click, activate auto-tint.

That’s just one idea, though. A red channel would be a great addition to this lantern however it might be implemented.

I would not mind it gaining RGB aux, either, or at least the pads on the updated driver so any of us who may care to can add aux emitters.

Actually, there are two LT1 product pages. The one above, and another for the “new” Anduril 2.0 version for CAD ~$79: 67.23€ 34% OFF|Sofirn anduril 2,0 lt1 usb c wiederauf ladbare Laterne Camping Licht 8 * lh351d Taschenlampe Außen lampe|LED-Taschenlampen| - AliExpress Is there a consensus on which is better?

Also, there is a coupon for CAD $2.56 off.

And then there’s another coupon (7JM0TD4QV7M9) for $14 USD off $20 USD which I don’t know how to apply. Entering it in the “promo code” field before checkout shows “We don’t recognize this promo code.”

Does anyone know what the best possible final price is?? These puzzles are quite… let’s say, entertaining.

Now it shows a different code for 30% that also doesn’t work.

I have and still use/test the same original production prototype, mine is a little beat up, but i run it often outdoors, for camps, all to still test its durability. I do the same with the very first prototype i built from a Sky Ray King light, that uses the Samsung LH351D 2700K LEDs, (that are the newest upgrade the old lantern got) That old prototype uses a Nanjg 105c modified driver, the SRK body, and a simple TP4056 charging module. It worked, and still works as a simple lantern design that became the predecessor to the BLF Sofirn LT1 we have now.

Yeah, it’s pretty nice overall. I think I actually prefer its more-plain top design with a simple curved handle and no O-ring or extra bumps. It works well.

As for the LT1-mini, I’m not sure how practical it will be outdoors — because of its narrow base and relatively small surface area for the diffuser. This makes it hard to place on uneven surfaces, and the higher surface brightness constricts the pupils more at the same lumen levels as a larger design. But it works well indoors, fits into a pocket, and would probably be good when clipped onto a belt or something. I’ve been using it a lot as a candle and for general illumination.

The LT1-stout seems interesting too, as a lighter alternative to the original LT1. Since it’s wide, it should be pretty stable and have lower surface brightness for less glare. But since it’s also short, it won’t be as good when placed on a table or something… it’ll generally need to be raised up on top of something else.