I've bought a pile of batteries separately, on the theory (hope!) that shipments without batteries might arrive faster.
However, I imagine that everything will be jumbled together, and so everything will probably be sent via the slow barge.
That was my theory too. Got a whole mess of new sanyos on the ready.
is it possible to get a definitive answer on whether or not ‘included cells’ will affect shipping times?
thanks!
(as a confirmed flashaholic of over 7 years now one would think I would have plenty of cells on hand 
Calculation time
(scroll to the bottom if you can’t be bothered)
4 × 3200mAh cells = 12800mAh
The lantern is designed to maintain a visually constant brightness across the colour temperature range, so although it has 10 × 7135 chips enabled by default - 5 chips each for the warm and cool LED channels - it never runs them all at full power.
At full power, set to 2700K or 5000K, it runs 5 × 7135 chips for a total of 1750mA. Set to a mid-range colour temperature, you’d expect each channel to run at half power, for a total of 1750mA, but it actually has to use a bit more to maintain visually constant brightness whilst mixing the warm and cool channel.
[Insert Jedi engineer hand wave]
The worst case is probably about 2000mA.
12800mAh ÷ 2000mA = 6.4 hours.
That will almost all be at constant brightness, tailing off a bit at the very end. The lantern has 4 LEDs EDIT 8 LEDs , so:
2000mA ÷ 8 = 250mA per LED
The LH351D datasheet gives average lumen ratings at 1050mA:
2700K: 340lm
5000K: 380lm
[hand wave] Call it one quarter of that at 250mA, because LEDs are more efficient at lower currents, but there are four of each LED, so we can just add those figures together:
340lm + 380lm = 720lm
[hand wave] and subtract 20% as a rule of thumb for optical losses, so we have 80% left:
720lm × 0.8 = ~570lm
for 6.4 hours. Pretty decent
If you have a USB powerbank capable of at least 1.5A (the maximum input current the lantern will accept at 5V), then you’ll only be drawing 500mA from the cells to get your 2000mA to the LEDs. In other words, if you have enough powerbank capacity, you can quadruple the lantern’s endurance at full power to 25.6 hours.
You can then remove the cells and keep going at 75% - [hand wave] ~450lm - for as long as you have external power. You’d be better to run at less than 75% and let the lantern use the spare power to slowly recharge your cells, though; leaving the cells in a discharged state reduces their service life.
The lantern can also accept input from a 12V car battery
So, pick your colour temperature and enjoy the 90+ CRI for:
- 6.4 hours at full power (~570lm) on 4 × 3200mAh cells alone.
- 25.6 hours at full power (~570lm) on 4 × 3200mAh cells and a decent external power supply.
- Indefinite operation at 75% (~450lm) with no cells and a decent external power supply.
- Indefinite operation at anything under 75% (~450lm) with a decent external power supply and slowly recharging your cells.
This is an extremely versatile device :+1:
Thanks Phlogiston, I was going to do something similar, your numbers are close enough to mine to not quibble.
I will mention a few variables though.
1) The 7135 chips have some tolerance on them, I did not look it up. But real data is indisputable. Lexel posted this video:
That shows with seven 7135s the current from his power supply was 2.54A. That translates to 0.363 A / 7135 roughly, ignoring any losses to run the control circuitry (which are pretty small). So seven 0.35A rated parts are averaging running at 0.363A for each part at 100% duty. The video also shows while tint mixing is going on, the current dropped. ToyKeeper has fixed that phenomenon, its now much more consistent across the various tints. But not exact, and that’s another variable . . .
2)Another variable is the ramp DBSAR mentioned in this post . IIRC, the steps, nor the ramp, necessarily take you to 100% on. At least for the D4 firmware they don’t, unless one programs them that way. ToyKeeper may have changed the firmware for the lantern to default to full range for both ramp and stepping (it would make sense), but if she did not that would explain the longer run times that DBSAR is reporting in his post.
Below is a preliminary copy of the UI diagram for the lantern, it shows what I mean, the ramps and steps don’t extend the full range of the item by default. I know the diagram needs some tweaks, like changing the demarkation between 7135s and direct drive, as there’s no direct drive. I also believe ToyKeeper took out the thermal configuration option, as there’s no need for it, the driver board will never get hot.
The reality is that you’ll get what you get for runtime, there’s really no one answer fits all. But Phlogiston’s 6.4 hour number is likely an accurate expectation for 100% duty and 4 3200mAhr cells.
Thanks, sbslider - those are all useful things to keep in mind!
For completeness, I’ll add that charging time at 1.5A for those 4 × 3200mAh cells will be something on the order of 10 hours with the lantern switched off.
I believe the lantern can be set to charge at either 750mA or 1.5A using a solder bridge - charging at 750mA would be something on the order of 18 hours.
NB: the effect of the constant-voltage phase during a Li-Ion charge means that charging time doesn’t scale exactly with the chosen current.
[Jedi engineer hand wave]
nice calculations :+1: Math was never my strong point 
Maybe i will try to do a full run test again using the best matched cells i have at full charge, in the 5-7135 sample on its maximum mode and somehow set it up to measure lux through out the full run time duration, ( i found a lux meter ap for my S9 Android that seems to work well.
for most of the time though, like flashlights i never run the lantern at full throttle, pedal-to-the-metal, hammer-down, screaming at max, i seem to always use the next mode down from maximum because i know it will add run time and run it cooler, while its still lots of lantern light compared to most of all my other modified lanterns. One reason why i hope Matt (VestureOfBlood here in BLF, AdventureSportFlashlights elsewhere) can get a sample of the lantern to review and test on his Youtube channel as he has the ability, tools and experience to give the LT1 a good testing. ( hope your listening Matt! 
Thank you
Just don’t mention calculus… [runs away screaming]
I’m like that as well, I just don’t like pushing equipment to the max if I can avoid it. In my experience, running one step short of maximum makes all manner of stuff last a lot longer. I suspect that commercial product engineering margins have been getting shaved a bit over the years.
That’s an important thing I’ve noticed about this lantern, though: you and the team have designed it with wonderfully wide margins on virtually all the components. I really, really like that :+1:
Please pencil me in for one more. Two total. I was unable to locate my original list number for the first one. If that number is mandatory please advise and I will keep searching.
Thank you list maintainer! I appreciate it.
Finally, a solid lantern. This will be fun.
fourbyfive
You were already in for 2 so now it’s 3
You don’t have to buy them all of course.
!
The batteries are all in parallel, so why would putting 4 near empty batteries not kick in the exact same LVP in each of them?
I was hoping it would be closer to 800 lumens and have 12 plus hours of runtime. Also I thought the lantern has 6 total leds not 4.
The LVP measures the batteries under load, which depends on the current. With four batteries parallel and thus the current per cell 4 times less, the voltage under load is a bit higher and thus the LVP kicks in a bit later. But it is all pretty marginal though, with the less than 2A current that the lantern draws the voltage difference between 2A and 500mA of a good battery is maybe 0.1V. I mentioned it more like a thought experiment than an actual recommendation.
I may check the theory in practice though, once the lantern is there
EDIT: Sorry, I was mistaken. The lantern actually has 8 LEDs (see this post from DBSAR).
Only 4 LEDs. Adding an extra 2 LEDs would add several percentage points to the cost without gaining much in the way of output or efficiency.
EDIT: The rest of this post is still fine.
The lantern comes with 5 × 7135 chips enabled per LED channel. You can enable a further 2 × 7135 chips per channel by connecting a couple of solder bridges.
That would buy you something like 30% extra output (not 40%, because LEDs are less efficient at higher current). On that basis, 570lm with 5 × 7135 chips per channel would scale up to about 740lm with 7 × 7135 chips per channel.
It doesn’t come with all of the chips enabled by default because that hammers full power runtime down to about 4.5 hours, and the lantern becomes uncomfortably hot when run for long periods at that level. The temperature can approach 60°C then, compared to about 40°C in the standard configuration.
Basically, you have the option, but you have to configure it yourself in full knowledge of the tradeoffs. 60°C is into scalding territory; manufacturers aren’t keen on making their devices do that as standard.
As for 12 hours runtime: unfortunately not in this form factor. It would have to be twice the size to manage that at full power, which means it would be heading for house brick size.
Mind you, it should be able to do about 300lm for 12 hours, which is often sufficient, and you always have the option to plug a USB powerbank in as an external “booster pack” if you need full power for extended periods.
A 20000mAh powerbank plugged into a fully charged lantern should run for roughly 11 - 12 hours in the stock (570lm) configuration. With all 7135 chips enabled, it should manage about 8 hours at 740lm.
Please note that these are all computed estimates; I don’t have a lantern on hand for real-life testing yet. I am on the list to buy 4 of them though, in full awareness of all these calculations, so you can see my confidence that they’ll work nicely for me.
The button has a blinking mode, but there is no breathing mode. Breathing mode increases standby power by quite a bit.
However, it sounds like this was about using the main LEDs while in standby. The closest function available would be the beacon mode when used at the lowest ramp level. But it’s probably too bright to use for that purpose, and would be annoying to sleep near.
One easy option is to leave the batteries out and power it only over USB. Then it could turn on automatically any time it receives power, with only a tiny change to the firmware. There’s a compile-time option to start at the memorized level at boot, instead of just blinking to confirm it has power.
To do more detailed synchronization though, it would require deeper changes.
Is there a consolidation post somewhere in this thread with the final agreed upon specs of the emitter, driver, color options etc? That first post is absolutely massive.
Im still innit for one, maybe two, but it seems that quite a bit of information is buried in this thread.
Also, and this is in no way meant to attack anyone, has the production firmware been thoroughly tested as to avoid the initial D4V2 FW issue? (Granted if the LT1 is like the Q8 it should be super easy to flash.)
I like a color like red for when I'm not using the lantern/flashlight. Makes it harder to overlook when you're getting ready to leave a place. Although this is only something I started caring about as I got older and my memory got less effective.
Your no fun, crank her up like a Screaming Jimmy! Got to love those 2 stroke Detroit diesels! https://www.youtube.com/watch?v=UYSUoixfttE