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

Please add me to list to purchase one

I don’t know if I missed it or not, but will the USB port on the lantern work with USB PD? Most lights that I’ve heard about, or have experience with, that use a type C port won’t charge with PD, you must use an A to C cable.

yes, it will likely work with the USB power delivery (PB) type chargers. the TP5100 charging chip can accept and regulate any input from most power sources i have tested.

It appears that protected cells use IC’s like this one, which provides over-discharge, over-current, and over-charge protection.

However, the over-charge cut-off is triggered at a specific voltage. Thus, the protection circuit will only shut off current after the voltage reaches that trigger, which it may never do if the over-charge trigger is above the output voltage of the LT1 charging board.

It seems likely that the cells would just sit and “soak” at ~4.2V for as long as the light were kept running. Cell charging current would drop quite low and nothing dangerous would happen, but li-ions are not meant to remain in constant-voltage mode indefinitely, which is effectively what happens with the light running and the cells charging at the same time.

So, the answer is probably that protected cells will not be a safeguard.

Please correct me if I’m wrong here as I don’t want to misinform anyone.

My collegue wants one. I’m in for one atm, please add one for a total of 2 :slight_smile:

Put me down for one please

Hey everyone my mom got sick and I’ve been offline for a few months… I live in the US….can you guys tell me what batteries you recommend for this one? Should I just get more like I have for the Q8 (Samsung 30Q) or does it need something different for output/longetivity?

Thanks and sorry if someone else has already posted this…

No need for something different.

Just go with something that has the best capacity to performance ratio.

Button top 30q batteries are fine, but a higher capacity battery like the PANASONIC/SANYO NCR18650GA will have better runtimes without reducing output.

I was thinking of something like the NCRs - needs to be button top though, right?

that’s correct

Thanks, SIGShooter. You’re doing a great job.

I’m already on the list for one (#1591), but would like to bump that up to two, just to further support the project.

Who’s the madman getting 10?!?

I would like to add 1 lantern, to make 2 total (#1372)

He might regret it if the v2 is even better ,better keep another $500+ spare :money_mouth_face:

A person that has a big mansion and wants a lantern for each room in case of a black out.

Since the names and quantities are easily gotten from the Interest list by user names.xlsx file linked in post #1 I can tell you it’s osb40000.

Better hurry and sign up for more if you want to beat him out :slight_smile:

Yes, and the lantern already has one. It’s the lighted button. The expected runtime per charge is over a decade. Basically, the power draw is lower than the cells’ self-discharge rate.

Not really. It has one power channel for warm, and one for cool, using PWM to control brightness. The efficiency shouldn’t change much at all at different brightness levels. However, the cooler tint emitters produce more lumens per Watt than the warmer ones, so if you want to maximize efficiency, use the coldest tint it can make.

No, I measured that it gets dimmer at 4000K… and I artificially increased it to keep the output relatively flat as tint changes.

The output is controlled on two axes — brightness and tint. The brightness is a value from 0 to 100%, and the tint is a value from 3000K (or 2700K) to 5000K. At either end, that ends up being 100x3000K + 0x5000K, or 0x3000K + 100x5000K. And in the middle, it would be 50x3000K + 50x5000K.

But this made it quite a bit less bright in the middle. So it increases the total brightness by as much as 150% in the middle, to compensate. That means, instead of 50+50, it actually runs the middle tint at 75+75 PWM. The overall power usage is still about the same as 100+0 or 0+100 though.

Internally, the actual PWM curves look like this:

… and the before/after for this correction looks like this. Before, it sagged in the middle… and now it’s not totally flat but it’s at least reasonably close.

Yes, actually. I adjusted candle mode specifically for this light… and also have been putting it on a table full of actual candles for comparison. It’s not perfect, but it’s not bad either. The overall brightness pattern is random, but it looks like this on a graph:

I also gave it a mode where it can change tint automatically with brightness, which affects all other modes. When used in candle mode, it should give at least a subtle coloration effect, but it’s not very noticeable.

Basically, at each end of the tint ramp, there’s an “auto” mode. One is warm when dim and cool when bright, and the other is cool when dim and warm when bright.

I think the auto-tint thing looks best when using lightning storm mode.

I am on the list for two, and would like to add 2 for a total of 4 please!