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

:smiley: :+1:

Thanks for confirming something I was curious about (being able to run on less cells). I had two other questions (and some searches of this very large thread haven’t turned up answers).
First, would the LT1 be able to run off only the USB input (with no cells at all)? As someone who plays several location-based games, I’m in possession of several large USB power banks and being able to run the light off one of those would be a huge benefit.
As a follow up, would it also be possible to not only run the lamp on the USB input, but actually be able to charge (even if it’s just a trickle) the batteries in the flashlight while doing so? Some non-scientific math would suggest it should be possible. If it draws 1.4A off nominal 3.6V cells, then it requires about 5W of power to drive the lamp. The USB connection is said to draw 1.5A, which at 5V, is 7.5W, so it sounds like the power is there to do it. I just wasn’t sure if the circuitry is capable of it.
Oh, one more question I just thought of… Does the charging circuit have its own protection circuitry, or should I still be aiming for cells with built in protection circuitry?

Little do you know how BLF will consume and warp your mind. You will have the overwhelming urge to buy the latest and greatest flashlight, knowing that it will be the last one ever. Then you will read another post about a new awesome flashlight, and the cycle will repeat it self all over again……and again……and again. :money_mouth_face: :money_mouth_face: :money_mouth_face:

Yep, yep and yep to a point. :stuck_out_tongue: I already tested all those abilities, and it does. i ran the LT1 test sample on a 2-amp Samsung phone charger on all modes with no problems with the battery section removed. (also did the same from a power bank) *see photo below with the LT1 first test unit running perfectly on the USB power with the entire battery section removed.

Also it will “trickle charge” the cells when the lantern is running on the lower modes, ( the modes that pull less amps than the TP 5100 can output, so it powers the lantern and the remaining charge amps go into the cells, but i do have a concern about doing that at the same time as the lantern running, as it can likely trick the TP5100 charger into continuously charging the cells after they already fully charged as the lantern amp-load tells the charger to keep producing charge output possibly. )

That’s just awesome actually……

This thing should be call the BLF EABABLE1 (End All Be All Bestest Lantern Ever 1)! Seriously I cannot believe no one has made a lantern close to this good. The only one I ever found that really peaked my interest were the Fenix ones and I was never able to bring myself to hit the buy button. This lantern however gives me no doubts.

WOW, just WOW!!!
Damn, I guess I never needed a lantern, and Im not sure I will use it often, but this real nice!!! I guess I will use it outside as hell when I get it :smiley:
Good work! Took its time but will be a great light!
Thanks to all involved :wink:

BTW, and just to confirm, 18650 flat top cells will do the job, right? I saw it was mentioned the Samsung 35E (3500mAh) flat top would work! Is it correct?
I will order some batteries soon, for this and other lights and would like to buy them together!

Again, thank you :wink:

Sorry, but you need button top cells.

Oops, misunderstood it or misread it :zipper_mouth_face:
Thanks for clarifying BlueSwordM :wink:

Not I can spend my money in a informed way :smiley: :money_mouth_face:
I’ll be a good buyer :innocent:

Please add 2 more for me.

Thank you.

I’ve been waffling about if I want a second one or not… Why the heck not.

Put me down for a second one.

#463 in the list.

Okay, so it sounds like just to be on the safe side, it would be a good idea to stick with protected cells (and maybe just charge with an external charger if I want to charge while the lamp is running — I’ve got a USB 18650 charger so that’s not a big deal).

Protected cells wouldn’t do anything at all in this case.

It’s not actually dangerous. Just bad for cycle life for the cells.

Unprotected vs protected does not matter at all.

Bad for cycle life due to the low drain? I planned to use four protected 2600mAh 26F’s and some unprotected 30Q’s, but not together of course. Is that a bad idea?

If as suspected the internal charger keeps charging the cells forever when the lantern is on, running off USB, the cells protection circuit would be a safeguard?

Will the upgraded (V2) version of the lantern begin development when the V1 lanterns finish shipping or have both versions been developed side to side?

As i do not know if the TP5100 charger chip would actually do that, i think either Toykeeper or Lexel would be more qualified & knowledgeable in that category than i am.

The lantern running without batteries, off a USB power source, opens up quite a few options i was not aware of! It could even be turned into a home appliance… The battery tube could also be replaced by any thread compatible foot design you want. Adding remote control should not be too complicated either (at least on/off)… This LT1 project is exceeding initial expectations in many ways! :+1:

I have ran it for hours during testing just plugged into one of the USB power ports in my RV trailer using a 10 foot long USB-C cable with no batteries in the lantern, proving the LT1 can be a multi-powered by almost any 5 volt power source that can supply at least 1.5 amps.

It’s bad for the cycle life of any Li-Ion cell to keep it charged at 100% and even worse to keep charging it once it has passed 100% charge capacity. For “float” charging set-ups, you are better off using lead acid batteries. Perhaps, if the terminal voltage of the charger were set below the max charge voltage of the Li-Ion cell, some of its life can be spared. But I don’t know that. I’m just guessing it might be possible. Best is to not overcharge, not over-discharge and not overheat the cell ever.