You can see the archived poll results on the Wayback Machine:
https://web.archive.org/web/20221220093741/https://budgetlightforum.com/t/-/72709
How do you like your battery check mode to work? This is initially for the X6v2 / K6 group buy lights, but also for more general use too.
The BLF A6 used a system where each blink represented about 25% of a full charge, much like how cell phones indicate signal strength with up to “four bars” of signal. This is quick and intuitive and accessible to muggles, but the resolution is fairly low. It does not offer a way to distinguish between 4.18V and 4.02V, for example.
The resolution can be improved by adding more blinks. Maybe 6 blinks would mean 100% full, or 8 blinks, or even 10 blinks, all based on discharge curves so you don’t have to know anything about li-ion batteries or the shape of their capacity curves. But the more blinks there are, the longer it takes to read the result and the easier it is to mis-count by accident.
One method I’ve seen is to do one blink for each tenth of a volt above 3.0V. So, 3.1V would be 1 blink, 3.5V would be 5 blinks, and 4.2V would be 12 blinks. This gives a reasonably accurate voltage reading, but it also means that 4 blinks means “almost empty” and it takes a while to read while the cell is anywhere near full. It also can be a bit misleading because 4/12 blinks does not mean 33% full. It’s actually closer to 5% full on an IMR cell. OTOH, it allows a knowledgeable user to gauge remaining capacity better regardless of cell type (different cells have different discharge curves).
The last method is two sets of blinks, one for volts and one for tenths. So, 4.2V would be 4 blinks, pause, 2 blinks. Or 3.9V would be 3 blinks, pause, 9 blinks. This method is shorter while full but takes the longest to read at 3.9V and below.
One other factor to keep in mind is that getting any of the above to work requires pretty careful calibration, and the more precise the blink pattern, the more likely it is to give an inaccurate result due to individual hardware variations. MCUs like the attiny13a are not very precise or consistent between units. So, it’s not going to replace a DMM… but it will hopefully at least be enough to let you know if the light will last for an entire hike, or if it’s low enough to put the cell in a charger.
So, with all that in mind… what style do you prefer? Capacity-based (muggle-friendly), or voltage-based? Fast, or high-resolution? Etcetera.
Mine would be 3 blinks: <3.6V, <3.9, <4.2V.
0-5 for 20% increments. 
But some batteries have a quicker drop off at the end so not sure how well the low end would work. 20, 16.6,12.5, 10 for 0-5, 0-6, 0-8, 0-10
It would be good if you could switch to another style via programing mode. Like 0-12 blinks, one blink for each 0.1v above 3.0v.
Is this for tiny13, 25 or 85?
My preference is 4/5/6/8 blinks based on capacity. I use HKJ’s discharge test curves to determine where to put the divisions between blinks.
This isn’t for any specific MCU, but on the attiny13a I doubt there will be enough room to offer more than one style on a single driver. Also, the “volts + tenths” option takes significantly more ROM space than any of the other options… so it might not be feasible in BLF-A6.
I really like the way the A6 SE is very simple to understand. But saying that I really don’t care, I just can’t wait to get these lights!!
It would be nice if BLF’s poll system supported approval voting (vote for one or more), or Schulze Condorcet (rank all choices). But I guess plurality (vote for exactly one) will have to suffice.
I really like the way it is now, but the 25% spread can be huge in certain circumstances. Knowing more exactly what is there (volts and tenths) could be very helpful to know… grab another cell? Swap in a new one? This is enough or I need top end as this one won’t quite do it… the way it is now it might show a fairly full cell but that might mean a substantial lumen output loss over a fresher cell. All things are relevant, of course.
Keep it like it is but shoot for volts and tenths in the ATTiny25. 
The way it is now also serves as a beacon, an excellent option.
Oh boy - look'n like: Off we go, to volts and tenths I know... 
Hhmmm, I'll have a go it, not sure when...
I am a “whole and tenths” sort. I like the way the Nitecore MH20 indicates voltage.
Ditto
I prefer knowing the voltage than knowing the %, % seems to be less accurate like what we see in powerbanks where it jumps from 75% to 25% . And i
Know most blfers care more on the battery health than the remaining battery capacity.
Hmm, I was hoping for more consensus… but it looks like it’s close to an even split so far. 12 votes for percent-based methods (with some disagreement about how big the units should be), and 11 votes for volts+tenths. And a surprising zero votes for the guppydrv tenths-only style.
Hopefully more votes will come in and provide more of a clear direction.
Me too!
I'm used to the zebralight 1 to 4 blinks for battery status and find it works well. If I want to know the actual voltage I'll grab a DMM. Unless the driver components allowed for accurate voltages without individual unit calibration it seems the best way to do it in my mind. If the driver allows for accurate voltages then I would favor the 2-4 blinks then 0-9 blinks, volts and tenths.
I vote for voltage indication, not % capacity.
% capacity will not be accurate for different types of cells (ICR vs. IMR vs. Hybrid).
If you know your cell curve then voltage is more useful.
I use 0-5 flashes for 3.4, 3.6…4.2 V.
Another question - Is voltage under load not more useful than no-load voltage?
*EDIT for clarity
I’m the first vote for the Guppydrv style. This is because I use a lot of lucidrv drivers.
I can also go with volts and tenths.
I’m new here, and don’t know much about these cells, so take what I have to say as a NON EXPERT opinion!
I don’t know if this is what Del meant above, but rather than blinking whole and tenths of volts, why not start with 1 blink for the lowest voltage that should ever be allowed and go up from there.
so assuming 3 volts is the min voltage on a cell (which works really well for the conversion, but is probably not right, is it 2.8V?):
table(table#posts).
|voltage|blink|
|3.0|0|
|3.1|1|
|3.2|2|
|3.3|3|
|3.4|4|
|3.5|5|
|3.6|6|
|3.7|7|
|3.8|8|
|3.9|9|
|4.0|10|
|4.1|11|
|4.2|12|
|4.3|13|
This satisfies the muggles like me - “More blinks = more juice = more run time” as well as people who really want to know what is happening - “Ah yes, 8 blinks, I have precisely enough life in this battery for my 15 minute walk if I do not exceed mode 3.” It removes you, Madam ToyKeeper, from having to attempt to average the curves of every possible cell to guess at a best approximation of percent of battery life left. It also means that as the cell gets closer to empty, you waste less battery life telling the user that fact.
Lazy-R-us
[edit]arrgh - this is already an option I just didn’t read all of them. Well, it seems like an even better idea now that I know someone else had it first.[/edit]
Haha I’m the second vote for #3 (6%). Shows ya what I know. I think that would be good enough for me to realize where I’m at on bat life. But I haven’t really let mine get below about 3.9v. I can wait 9 blinks!
I prefer the first and the last one.
The 1st if I’m in a hurry while the last method, which is implemented in my TM16, is very useful when I want to use my light in mainly turbo or high mode.