7242

Sorry logging in after a long time. This is finally live!!!?? Excited hehe. Where do I buy it?

7243

If youā€™re interested in being added to the interest list post in this thread that you want to be added. You will then be sent a PM when the buy goes live.

7244

Yes since the cells are in parallel you can run it on any number of cells.

7245

ā€œAlso make sure that the batteries are in a similar state
of charge when installing them. Do not install
batteries with more than 0.1V difference in resting
voltage between them into the LT1. Failure to follow
this precaution could result in fire and damage to the
LT1 when the head is installed.ā€

So I need to check the voltages of cells before using them for safety? Looks dangerous haha

7246

ToyKeeper, iamlucky13, thank you very much for your insightful answers.

I was worried because I built a bike light with many parallel 5mm LEDs 15years or so ago, and some failed quickly. But as even in the worst case a single LED with all the power would not be overdriven in the LT1, I see now that this is one of the differences that makes the design safe.
Thanks again,
Julian

7247

SIGShooter, after downloading and reading the manual for a more complete understanding of the capabilities, I believe Iā€™d like to purchase a second unit with batteries. Iā€™ll probably gift it to my cousin, who is walking the Appalachian trail in approximately 100-mile increments over a period of several years.

If I understand the procedure correctly, this means that I will be able to purchase my original unit early (though I donā€™t remember my number, and canā€™t find it!), and will then receive a second purchase code substantially further into the fulfillment phase, correct?

BTW, I own two SIGs.

best regards,

Martin

7248

Hi DBSAR, I just downloaded the manual and found it very informative. If you are still looking for input, I believe the sixth paragraph in the troubleshooting section on the last page wants to end as: ā€œreplace the O-ring with a suitable replacement if it is wornā€.

Also, I noticed one or two instances where you use the British spelling of ā€œbehaviourā€, but I donā€™t know whether this is the Canadian spelling as well.

best regards,

Martin

7249

I was an IC and semiconductor design engineer for many years, and we exploited this principle frequently. OEMs purchased devices from us in lots, and we guaranteed parameter matching within the lot much tighter than our general specifications. And they built their products using devices from within a single lot to take advantage of the parameter matching. Often the entire lot would come from one wafer, and weā€™d perform autoprobe testing to screen and eliminate outliers.

The problem described by Julez might occur if the lantern manufacturer cuts corners and doesnā€™t build his product from within individual lots. Random devices used in parallel could be more of a problem.

Julez, your bike light may have had the current-hogging and burnout issue because you were using random LEDs that may or may not have come from a single lot, and therefore exhibited greater variation in forward voltage vs current and temperature.

7250

Not yet, but probably very soon if I understand correctly. I think the first batch might even go up this week if things go well, but Iā€™m not in charge of that so I donā€™t really know.

This is the same for almost any device with multiple battery cells. In this specific case, all the + ends connect to one shared piece of metal, and all the - ends connect to a second pieceā€¦ so as soon as they make contact, they charge or discharge each other until theyā€™re at the same voltage. This isnā€™t an issue if theyā€™re already at the same voltage to begin with, or if theyā€™re kept together as one married set. However, it can cause damage if wildly different voltages are used.

The recommendation for this lantern is to get a set of four new identical cells, put them in the light, then never take them out again. It has a built-in charger, so basically just plug it in once in a while to add fuel. I usually donā€™t even charge mine all the way, since the cells last longer when theyā€™re kept closer to half full. When it gets down to ~20% full, I charge it up to ~80% full. And then it usually lasts months before I need to charge it again.

Or thereā€™s Denā€™s method ā€” use it for illumination at night, and plug it into a solar panel during the day. It can provide off-grid lighting for years before the batteries need to be replaced.

7251

I would be interested in two.

7252

@toykeeper. Thanks for this long very insightful and helpful post. Are there runtimes/lumens available? Would you recommend the sofirm batteries or buy my own?

7253

I take care of any last minute changes about the manual.

Thanks for your input funkychateau. I have corrected those findings. The BE "behaviour" has now been replaced by AE "behavior".

A new revision will soon be published accordingly and will probably be supplied with all LT1s as of batch #2.

7254

Are there any news about the colors? Are the 3 colors for product start now safe?

7255

If batteries are inserted in the wrong way (reversed polarity) they will cause a short, i.e. the batteries will heat up instantaneously. Usually, in such a case the first thing that happens is that springs start to melt/collapse which is actually good because a collapsed spring may be unable to make contact any longer to the shorted battery. However, there's no guarantee that the electric connection will be fully broken. Eventually, it could get to the worst case to happen, the so called thermal runaway or the explosion of the battery. Besides of all of this, the driver or its components may also become damaged.

In order to prevent these things to happen most manufacturers implement a so called reverse polarity protection that works as an electrical barrier. However, I did not find any sign of a reverse polarity protection in the manual. Maybe someone else of the BLF LT1 team can chime in to tell if there is some protection in place already and I will be happy to amend the manual accordingly.

Trying to answer your questions...

using a wrong charger? (If i recall correctly, sb mentioned a 5V 2A charger as ā€œbest choiceā€?)

ā–ŗ Very unlikely, you may use any Li-Ion charger that can handle 3.7V cells if you want to recharge batteries externally. Make sure to not overcharge cells ("4.35V option"). If you use the internal charger, you may use any suitable USB charger.

- inserting all batterys the wrong way round?

ā–ŗ Without reverse polarity protection, this is highly dangerous - so, always make sure that buttons/positive terminals face to the head of the LT1

- inserting some batterys the wrong way round?

ā–ŗ The same applies here - there's no difference.
- running the lt1 very long, until the battery is dead? (unprotected cells)

ā–ŗ Since the LT1 has a low voltage protection at 2.8V, there's no risk of killing the battery. However, it's recommended to recharge the batteries soon once they are fully discharged.
- running the lt1 very long, until the battery is dead? (protected cells)

ā–ŗ The same applies here. Usually, protected batteries have their own LVP, so all you get is a bit extra protection. Make sure that protected cells are no longer than 70mm.
- other behaviours i may have missed?

ā–ŗ Always check you batteries for any obvious damages (damaged shrink wrap, deformations) and only use button top batteries. Never use flat top batteries (even if they seem to work). You risk causing a voltage imbalance with maybe only 1-2 of 4 batteries making contact to the brass ring on the LT1's head that could subsequently lead to damages on both the LT1 and its batteries.

7256

I am very impressed with the clarity, thoroughness, and professionalism of linked LT1 manual, and see the workings of an accomplished technical writer. You have some real organizational and writing skills. It will definitely help with the LT1 roll-out, and be an incredible reference! Thanks!

7257

Thank you ActiveAl, but credits should go - at least contentwise - to sbslider, stereodude and nicois for they have done most of the changes on the manual. I'm more than happy that with so many helpful members here on BLF we were able to make this manual as good as it gets. My task is more or less the final layout and the subsequent German translation (work-in-progress) that Sofirn will be using for the multilingual manual as of batch #2. Maybe credits should also go to Google for their fantastic cloud solution, making collaborative work much easier than I have ever dreamed of. :-D

7258

This lantern is a winner for sure. I just read the manual and ā€¦ wow.

Do you have a plan for a next release?

A idea: 1x18650 lantern good as like the blf lt1. (Mini BLF LT1).

Thank you.

7259

From my understanding:

  1. The internal charging circuit is limited already, and uses a USB port. There should be no danger at all from using any USB charger that you want to use. In fact, this lantern is meant to be able to charge from any source, including under-powered chargers, and solar arrays, which might blink in and out from cloud cover, etc. Itā€™s meant to be very flexible in order to work in a variety of conditions.
  2. The LT1 driver should have a raised brass ring for contact with a button top cell only. Itā€™s a pseudo-protection from reverse polarity. Itā€™s not perfect. Cells should only be inserted with the positive pole facing up toward the driver. However, as long as the cell wrapper is unbroken and wraps around the bottom of the cell, it is likely that it would NOT be able to make electrical contact with the ring.
  3. Inserting some of the cells the wrong way should only be a threat if the bottom of the wrongly inserted cells can make contact with the positive contact ring on the driver. But if they DO make contact, it will effectively be shorting those cells across the other cells directly. This WILL heat up all of the cells to possibly dangerous temperatures. Thermal runaway of high energy cells inside the battery tube can be dangerous at least three ways - fire, explosion, and poisonous gas. However, I can say myself that the probability of thermal runaway occurring is likely not as high as we might fear. Iā€™ve had cells crossed in a SRK before and aside from getting hot to hold within a few seconds, nothing spectacular happened. My friend thought it made sense to load freshly charged cells two up and two down, like most consumer electronics. :open_mouth:
7260

I love this idea.

7261

Please put me down for 4 more to be on the safe side, someone I know may be interested.