You have a point, but it basically already exists (4x XHP35):
9V triple is more interesting to me but no one else seems to want it (besides LUX-RC drivers) and boards would have to be remade or old Noctigons brought back from the dead
I think the point being raised is not about the efficiency, but about regulation.
In basic theory, a good buck driver can maintain regulation until the battery voltage drops to the forward voltage. In practice, I’m not sure it tends to work out quite as expected. Also, while a forward voltage around 2.9V may be common at an LED’s standard rated current, at 3A, the forward voltage rises to typically 3.2 to 3.4V depending on the LED (the 219C is known for having a low forward voltage. The XP-L HI tends a little higher). So even with a perfectly performing buck driver, you could fall out of regulation with 1/3 of the battery charge left.
As far as efficiency, a lot of current generation LED’s have a forward voltage around 2.9V at rated current. For a battery that averages 3.7V throughout the discharge, that should yield 78% driver efficiency. Loneoceans report 93% efficiency from his driver. Of course, linear drive efficiency improves at higher currents due to the higher forward voltage, but LED efficiency decreases, so there is a net decrease in overall efficiency.buck-boost driver over a 95% efficient buck driver, and definitely over a 78% efficient linear driver.
That said, as I understand it, boost-buck circuits tend to make a small efficiency compromise compared to buck-only circuits.
And i’m reading only bla bla bla
The best BLF driver version is comin’ and i’m sure as hell buying many for other hosts i have
Hello,
the moon mode is important to me and is used often.
The moon mode at the driver is higher than the output of the stock driver. But you wrote, it is possible to reduce this even further. Do you mean by software (me) or hardware (you)?
Thank you.
I second the request for the lowest possible moon mode, one way or another.
Thirded.
I will buy at least 10 straight up
Thanks everyone for the great feedback so far, and thanks everyone for your patience.
Just a quick update - the first batch of Lume1-FW3X drivers have been produced. I am arranging to getting some shipped to me so I can validate the build.
More to come soon!
In addition, a lot of people have asked about Aux boards. Neal has produced some RGB AUX boards.
https://imgur.com/po5GYL3
Here's a very quick image of what Neal sent over. Tweaking of resistor values in progress for LED brightness. I do not know what his plans are for AUX boards but I see no reason why they cannot be offered for sale as well. Please excuse the odd effects from video to gif conversion.
It depends. The driver is running in Buck mode for most of the battery discharge curve. In fact, it is possible (though unrealistic) to have scenarios whereby the driver never runs into boost mode, for example if extremely low V_fwd LEDs are used (e.g. 2.8V), and when the cut-off voltage is set to be say around 2.9V. However, in the real world, nearer the lower end of the battery discharge curve, boost mode is typically very helpful. In your regular AMC7135 drivers, you'll notice that the LED output starts to drop significantly at the lower end of the curve especially due to the drop-out voltage of those regulators.
For example, at say a 2A drive, your LED may have a V_fwd of about 3.2V. With DCR losses in the wires, the driver needs to supply even higher than that, perhaps 3.25V. Then, you have to add the 120mV dropout voltage, and more DCR losses from the battery conduction path. So the cell voltage under load needs to be closer to 3.4 to 3.5V. Once the cell voltage drops below that, the driver falls out of regulation at the intended current. In the same scenario, the Lume1 driver continues to drive the LED at the actual set current even when battery voltage drops below 3V at the cell level, or during low temperatures (e.g. I noticed the Panasonic INR cells tend to drop in voltage much more when cold, compared to say a high drain 30Q). The Lume1 datasheet explains this in more detail. I'm not saying that this is a necessary design element - it's just a feature I wanted to have when I made the Lume1 driver.
I could also design a buck-only driver. With a 100%-duty-capable design, it's still possible to achieve excellent performance and efficiency over a standard linear driver, just that such a driver would begin to fall out of regulation once the battery is drained. If that behavior is accepted (which I think, generally should be OK since people do expect their flashlights to get dimmer as the battery is drained), then there's no issue with a buck-only driver. Hope that makes sense.
loneoceans, i don’t believe , i need schematics to replicate the process 
Am I correct that the google sheets is now moot? Is there a way to get added to the google sheets so I can get notified when these become available? Just started getting into flashlights, and really excited about this!
“LED is 2.8Vf or 3Vf” - what LED, people are using different LEDs, what if someone is looking to drive high power UV LED, those have Vf in 3.5-4.0V range. This driver is perfect for it.
That’s kind of my thoughts too. This driver makes led choices much broader.
Great work Loneoceans, looking forward to using a couple of these. :+1:
Hello all,
For those still following this thread, I have some updates from Neal in the first prototype factory batch of the Lume1 driver!
Thanks!
Hello all,
Just wanted to post a note for all those who subscribed to this thread. Thank you all for patience. Also, many thanks to Neal from Nealsgadgets for his hard work getting the logistics to line up well. It was a challenging process due to all the delays and logistical issues due to the pandemic, but Neal has finally got the first batch of the drivers for sale!
These drivers are just off the production line and they're so new that I haven't yet got my hands on them yet, I've only done validation work with pre-production samples.
You can buy them from Neal here! https://www.nealsgadgets.com/products/lume1-fw3x-driver
For a limited time, use Coupon Code LUME1 for 20% off!
Thanks everyone! Future updates will be posted in the main thread here: https://budgetlightforum.com/t/-/60947
Thank you Loneocean!
I hopethey didn’t deviate from your design...
Thank you loneoceans for making this driver possible.
I ordered 4, to replace in all my compatible lights. I hopethis design will become available in other sizes so it can be used in other lights as well, even though making it smaller may not be possible.
I would suggest to Neal to include the required wires with the set of driver and aux board, as many of us, myself included, do not have coloured silicone wires of the appropriate size.
Snagged 3 of them… Thanks lone oceans for making this and making it happen! 
Thanks, ordered 5 to start
Neal verified that no cables are included with the Lume1 driver / aux board set. Can anyone give me the specs for the cables so I can get some?