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

[BlueSwordM]

@mopar, currently, only USB-C is a good connector for power transmission, since it includes dual power lanes, which massively lowers contact resistance and overall resistance in the connector.

It’s actually a very good connector in terms of power density under 100W.

[randall.peterson3 (randall.peterson3@gmail.com)]

Hi, can you please put me on the list for one.

[eugene188]

@DBSAR

@eugene188

Is there any final numbers on runtimes in max? I searched and found a post claiming over 12hrs on 3200mah batteries, but then calculations said it was supposed to be about 7hrs.

Also anybody from Toronto/Ottawa that would want to split shipping from 18650Canada? Pls PM

Are you located in Toronto? (I live 45 minutes north of the city.)
I’m still running tests for run times, ( as it varies a lot depending on the cells, the ramp vs. stepped, etc. at one test i got past 12 hours on the 5-7135 factory default using the stepped modes on four 3500mAh 35E cells, then did the test again with a different set & type of GA cells using the ramp-high mode and got 8 hours, but it was difficult to measure if there was a step down (or gradual ramp-down) as my lux meter stopped working for my sphere.

Sweet, I feel like 8 hours on max is probably more than I would actually need as when it gets really dark out while camping, just a little bit of light goes a long way. I bet the LT1 will go for weeks on the lowest setting. Last time I tested the Zanflare T1 on lowest setting it went for like 14 days.

Well I live in Ottawa, but my parents are in TO. So I would go back on the long weekends or things like xmas holidays. That’s why I wanted to try my luck with both cities and see if anybody was at either one.

[eugene188]

@Phlogiston

@eugene188

Is there any final numbers on runtimes in max? I searched and found a post claiming over 12hrs on 3200mah batteries, but then calculations said it was supposed to be about 7hrs.

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 for the hand waves. i’m kind of excited to get this because it can run off a powerbank or a solar charger.

[leftdisconnected]

@rost333

This company however (Baseus) have really good and high quality products:

Page Not Found - Aliexpress.com

I suppose this could be considered on-topic since people will need power cables for their LT1’s , but is everything this company sells also of good quality? They have some USB-C cables that seem okay, but I don’t want junk; I want high-quality cables with large-gauge wiring. I have a terrible time finding quality USB cables and would love to find a trustworthy brand that runs their own store on AX.

Most fabric-wrapped USB cables contain tiny wiring with high resistance. Are the ones linked above any better? I don’t believe any of the advertising as every brand makes similarly impressive graphics. Any tips appreciated, but I’m sure that there are other threads more suitable for this subject, so I don’t want to cause a diversion.

[lumiere]

Has the prototype been tested with a USB-C to USB-C cable?

(Some incorrectly made devices only charge with a USB-A to USB-C cable).

[GrkGod454]

I am interested in one please.

[Mobileschoney]

Interested

[Propeak]

@leftdisconnected

@rost333

This company however (Baseus) have really good and high quality products:

Page Not Found - Aliexpress.com

I suppose this could be considered on-topic since people will need power cables for their LT1’s , but is everything this company sells also of good quality? They have some USB-C cables that seem okay, but I don’t want junk; I want high-quality cables with large-gauge wiring. I have a terrible time finding quality USB cables and would love to find a trustworthy brand that runs their own store on AX.

Most fabric-wrapped USB cables contain tiny wiring with high resistance. Are the ones linked above any better? I don’t believe any of the advertising as every brand makes similarly impressive graphics. Any tips appreciated, but I’m sure that there are other threads more suitable for this subject, so I don’t want to cause a diversion.

Actually, I think this is very important too. Perhaps a BLF project for a variety kit of high quality USB cables? I’m always getting annoyed with my tablet or phone not charging properly because of rubbish cables. Leftdisconnected, would be very happy to hear of anything good you come across. This is so annoying with power extenders and earphones etc too. Aren’t there any good quality brands out there?

[RiGiD]

Can I be added for a second light? Both with batteries, please.

[methnen]

On the cable front I’ve anecdotally gone through a large number of USB/USB-C type cables from different manufacturers and have definitely settled on a favorite.

The Anker Powerline+ II or Powerline II cables have been significantly more reliable for me in areas where there’s lots of pluging and unplugging and folding and pulling and all the usual wear and tear on a high use cable.

I went through a bunch of Belkin, Amazon Basics, Monoprice, Apple and other various brands and they inevitably fail on me both for charging only situations and for charging/data transfer situations.

As far as I can tell the only difference between the Powerline+ II and Powerline II cables is the + ones have braided nylon around the cable and fancier metal/rubber bits on the plug ends.

The cables hold up very well and for power delivery are rated at 100 watts which is the maximum for the current USB spec.

I can’t speak to having actually maxed one out at 100 watts but they hold up fine charging/powering a MacBook Pro which is around 60-90 watts of power draw depending on what you’re doing and would be more then sufficient I imagine for charing the LT1.

[Phlogiston]

The LT1 will draw less than 10W, even at maximum charging rate. An ordinary 2A USB charger and basic USB cable can cover that, so decent USB-C cables will be fine.

I can recommend Anker for good USB cables as well. They sell on Amazon, and I’ve found them worth the money. They make good powerbanks and wall chargers too, by the way.

I wouldn’t even consider buying USB cables on AliExpress or Ebay.

The LT1 will be my first device with a USB-C port, so I just bought some adaptors:

https://www.amazon.co.uk/gp/product/B078NLG53R

and I’ll reuse my existing micro USB cables. I’ll get some proper USB-C cables when I have more devices to use them with (next time I need a new phone or tablet, no doubt).

[DBSAR]

@Phlogiston

Amazon.co.uk

and I’ll reuse my existing micro USB cables. I’ll get some proper USB-C cables when I have more devices to use them with (next time I need a new phone or tablet, no doubt).

I bought a 5 - pack of those adapters too, they work great as i have some good quality USB-Micro cables of all lengtths.

[djans1397]

I’d like to add one more lantern to my order for a total of 3 lanterns with four cells each.

What’s the latest on ETA on these?

Thanks much.

[MNLegoBoy]

@djans1397

I’d like to add one more lantern to my order for a total of 3 lanterns with four cells each.

What’s the latest on ETA on these?

Thanks much.

Soon™

[Chappy]

Please put me down for two lanterns - Thanks!

[TylerDurdenThree]

Interested

[MtnDon (Don Miller)]

I find Anker cables, adapters, etc. to be very good as well.

[superbob47]

Please put me down for another (for a total of 3), thank you!

[Caleb-v]

Interested. Please put me down for one.