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

The charge circuit only supports basic charge currents. One of the design criteria was to be chargeable from low current sources like a small solar panel. A high current fast-charge was not pursued for various reasons, including maximizing cell lifespan with slow charging.

I understand now. Thanks
All the Best,

IIRC mine stops at 4.17 also. I tend to only charge it until I see 4.1 blinks anyway. Had it for 8 months now, maybe charged it 4 or 5 times? This time of year it doesn’t get used much, but from Oct to Mar/Apr, it got used an hour a day easy. I love candle mode in the morning.

somehow having a sunrise alarm function would be off the charts.

If it had a programmable timer, (for turning it off or on) would be a great option for those who want the LT1 to turn on at a certain time & off at a certain time every day. (especially for those living in remote locations of the North where there are 40 days of night and no sunlight.

I couldn't help but suddenly remembered this film... :-D

I guess I’ll bring this up again - I recognize there might simply be no one browsing the thread with the time and skills to design a custom emitter PCB for this lantern as a mod option.

But is anybody else at least interested in alternative emitter options? Usually there’s a decent number of people eagerly looking for even higher color performance than R9050 equivalent and a slight green tint on the cool end. Should we keep a conversation simmering about this or let it go?

:+1: :smiley:

I do have the original design drawing, but the production one has been changed a little from that.

Too true. The alarm clock function might be hard to do (as far I understand), the timing is not really swell in these circuits over a period of time.

BUT, I would trade all the blinkies (keeping SOS and Bike for a lantern) for a sunset that could be programed as far as time and how it stepped down.
AND, it needs to be easily started. Like at any brightness, do the Sunset click, and the light winks at me to let me know all is well.
Then the light starts stepping down from that brightness according to the arranged program.
No bright flashes while getting there to blind my night vision.

For example my bedside Olight. Love the TIR, Hate the cold white color.
Two clicks from any brightness, and I get a wink. 2 (or3?) minutes later it turns off.
Need more time, 2 more clicks during the time out, and you get 9 minutes(?) before going dark.

For years my bedside light was an old Eternalight. Remember these?

It started out a full brightness - a whopping 15? Lumens.
Every few minutes it would drop one level, and give a little pulse. After a while it would turn off.
The step down let me know that it was going to go dark. And if I wanted more light, I’d better push some buttons.

I think I remember TK once mentioning that the Eternalight was the inspiration for some of her features.
I like the adjustable strobe for flashlights, nifty for freezing motion.

Too timid to reprogram it myself. I’d end up with a brick fro sure.

Still, it’s the best lantern the world has seen to date.
All the Best,

I’ve begged them many times to offer a a 4000k and Red XP-E2’s. The red is nice for a “Camping Lantern”, to not attract bugs. I’ve even asked them to send me a board, and I’ll do it myself. Barry said he would send one months ago, but never did

You could use a red filter… create something that would wrap around the outside of the translucent cover, so you can remove it when needed.

A red filter applied on the outside would significantly decrease LT1's overall brightness while red light from XP-E2 LEDs would be much more efficient. I would also love to see an updated or enhanced version of LT1 with either additional XP-E2 photo red (660nm) on the PCB or - taking RobertB's idea into consideration - Sofirn could use LH351D 4.000K 90CRI plus XP-E2 (photo) red and maybe remove the tint ramping feature but use the free space on the MCU for some nice red light modes. Barry was a bit worried what to do with all the XP-E2 photo red that were sourced for C01R - here comes the great opportunity to use them in another fantastic light.

Anyway, I just encouraged Barry to have a look at this idea. He is thrilled about it and would like to discuss further options. I think it's the best to have these options discussed within the LT1 team with Dennis, Lexel, ToyKeeper etc. first to see what's feasible and reasonable.

That’s good to know. If I end up having time to learn a PCB design program, I might be interested in seeing it for reference. Currently, unfortunately, I’ve got too much going on to take on a hobby project.

That’s an interesting idea. I think it would be good if they are able to offer the board for sale, although since those are emitters with an XP footprint, reflowing the included board is an option.

I wonder if the low forward voltage of the red XP-E2 would cause any issues with mixing. I wouldn’t think so, but I don’t really know.

I see what you mean. Yes, with wanting to maintain maximum output, an external filter would be a detriment. Considering how the auxiliary LED’s appearing in Astrolux, Emisar, and FireFlies has been popular, you’d think a circuit could be designed to allow for auxiliary ones driven at higher amperage in the LT1, allowing for bright red or amber emitters. This way it wouldn’t cut into the existing temperature function of the main emitters. Then in UI you can click over into AUX control, to run independently or even simultaneously with the mains.

Just received my LT1 and I am impressed! Thank you to Sofirn, DBSAR and everyone involved in developing this lantern. I am a flashlight and headlamp guy and not into lanterns but this lantern is amazing! What a great price too. Wow.

Ok, maybe a stupid question

Is there an option for smooth ramping without tint change?
I would like the 2700 K all the way from low to high, for now it starts either warm and ends cool and vice versa

Sounds like you have auto tint ramping turned on. When the tint reaches the end of its ramp, it will quickly flash to let you know the limit has been reached. If you continue holding, it will flash again indicating that it has entered auto tint ramp mode.

Ramp the tint back up a little (click-click-hold) and then back down to 2700K and let go of the switch as soon as it reaches the end. That should exit auto tint mode.

Thanx Rayoui!

That’s it! That did the trick.
That part is not directly stated in the flowchart, couldn’t get it from the manual directly.

I have been off-line for a while with a work change, but I finally got a chance to go camping this weekend. My children (age 20 and 15) stole my LT1. We used it on the picnic table as a family, so I did enjoy it, but I was hoping to use the Lightening mode and bedtime mode. Didn’t get a chance. I was going to wait for the different anodization colors, but I think I’ll just take black at this point.

I have sent Sofirm a Private message requesting my remaining two codes, where are they selling them these days? Amazon? BangGood?

Or, you can go direct at https://sofirnlight.com/blf-lt1-lantern-tint-ramping-2700k-5000k-p0123.html