Convoy S2+ new firmware (biscotti) memory mode jammed

I would get a 7135*8

you can configure it in one of the 12 groups to put out 50% max and pretend you have a 7135*4 or however that works…

You can unlock a new mode later for moar power…
You can never do that if you are stuck with the 7135*3…………

Barkuti thanks a lot for trying to help!

I’ll be honest. I know you did your best to help me. You gave me lot of examples what would you do. But… now I’m more confused than what I was before. :frowning:

My biggest issue is that I don’t know how (in real life) certain amount of lumens are good for me (for what I want to use flashlight for, in this case ‘before sunrise flea market’).

I need flashlight to:
-last long
-don’t get hot
-have flood (I think I need ‘flood’ because, in my head, I think ‘flood’ with equally light up the whole ‘area’ in front of one seller, but maybe I’m wrong because it will give less ‘lumens’)
-to not have hotsopt circle ring (if possible)

^ one more explanation why I think it would be good to have a ‘flood’ type of flashlight is, when I come in front of a seller’s staff, if I use ‘thrower’ it will be like snipping some item which would ‘tell’ the seller I might be interested in a specific item (which I don’t want to reveal to him so easily because I want to bargain with him about the price, but not let him know I ‘really’ want it, if you know what I mean) :slight_smile: So ‘flood’ light would show me all his items, but not ‘directly’ point to a specific one so fast.

I was at flea market last Sunday, and I did noticed some people with ‘strong’ lamps. I’m sure some of them bought Convoy or simmilar ‘smart’ flashlight, but I knew about all this much less than now, and even if I tried to ask them about ‘what type’ of driver, emitter, or emitter bin their flashlight was using, I guess some of them woudn’t have time to bother with details, some probably wouldn’t even know, and some wont tell). I only noticed (if I remember correctly) that probably 2 out of 3 guys had lamps with that snipping hotspot circle ring. They also were switching off their flashlights so fast, which is what I don’t want to be forced to do. (I guess if they were using 7135*8, they didn’t wanted a lamp to get hor too fast, or to waste battery so fast).

justanotherguy, thanks for your answer!

Yes, I understand what you’re saying, BUT… even if I use 7135*8 at 50%, woudn’t that also (still) force the battery to lose power faster and to get hot faster?

One more thing that I read (post is 3 years old now) is that Convoy S2+ (at the time) didn’t had low voltage cutoff but only low voltage warning. It said that Toykeeper made a new firmware version (probably biscotti) but it was only for Convoy C8 at the time. Is it possible to get such option within the firmware that flashlight comes with? (trying to think about protection as much as I can)

0K. First of all, even if you care to use a warm high CRI emitter like a 3000K CRI80+ XM-L2 or 2700K/4000K CRI95 SST-20, you should get more or less 300+ lumens out the front of the flashlight with a TIR lens if the emitter is driven at 1.4 - 1.5 A (check some emitter reviews like Test of a Luminus SST-20-W 3000K 95CRI led -djozz- or Luminus SST-20-W 4000 K CRI95 color and output test -maukka- if you like). I'm already counting some optic and heat losses, but my figure should be close enough. The TIR lenses will provide you with a nice blanket of light (no hotspot at all), so no one will think you're "sniping" something unless you straight focus at it leaving it in the center of your beam. My close up work flashlight has a 30° TIR, and to my eyes it covers a 60° angle (the figure is a half angle metric). So ask Simon to bundle you at least 2 or 3 lenses (10°, 25° and 45°), or just order a "1pcs per degree" 5-pack (10°, 25°, 45°, 60° and :???: strip lens), that way you'll be able to test by yourself which ones you like better. A lens with a wider angle will spread out the light more, making the beam less intense and you may have to get closer, but at the same time you'll cover a wider area and be able to peek more items stealthily.

As I said above, you can get the SST-40 driver which goes up to 5 A or some Biscotti 8x 7135 driver both of which, in medium mode, will provide you with decent light. The SST-40 driver will give you almost 1.5 A in medium -30%-, while an 8x 7135 in medium mode will be somewhat below depending on the chosen mode group, so it'll be less bright. With 1.5 A at the emitter, a 3000+ mAh cell and a low Vf emitter, you'll at least have 2 hours of non-stop runtime, a little bit more in practice depending on the cell you use. Don't worry with the temperature thing, 1.5 A max means 5 - 6 W of burnt power at the flashlight, it doesn't gets too hot at that power (and anyway, the SST-40 driver has temperature control). I once used my nephew's S2+ with a headband to go jogging (40+ minutes, an after repair test) at night, and it performed wonderfully without getting toasted.

Runtime speaking you can switch modes to save power, and/or take more batteries with you if needed; it's a pretty quick swap.

Thanks Barkuti for your reply.

I saw your message about 10 days ago when you posted it, I just didn’t know exactly what to ask next, even though I felt like there is something that I still don’t understand. So I let the time pass, while trying to figureout whats that thing which still makes me confused.

First, since I’m still new to all this, I didn’t knew what CRI means. So I googled it and watched some YoutTube clips. If I understood correctly, CRI represent how good specific led diode can show the difference between different colors (they used 8 colors in some youtube examples). So in theory, CRI 100 is a perfect one. In other words, higher the CRI, better the led diode is. Correct?

I see that you said for XM-L2 it is CRI80+. Can’t that CRI value be more specific? For SST-20 you said its CRI95. From what I understand a diode with CRI95 should be good at showing the difference between colors, right?

2nd question: You suggested using ‘warm’ high CRI emitter (3000K or 2700K/4000K). When I was looking at the sales page of Convoy S2+ with XM-L2 emitter I saw that Convoy is offering couple different eminter bins to choose from:

XML2 U2-1A 6500-7000K
XML2 T6-3B 5000-5200K
XML2 T6-4C 4300-4500K
XML2 T5-5B 4000-4200K
XML2 T4-7A 3000-3200K

^ (btw whats the difference between ‘bins’ and ‘tints’ terms?)

Since there are photos attached at the same sales page, I decided that I most like how 5000-5200K appears (or ‘neutral light’). Maybe ‘4300-4500K’ (which should be ‘neutral-warm light) could be ’ok’, though its starts looking yellowish compared to 5000-5200K. But, anyway, what confused me is that you’re suggested ‘warm high CRI emitter’ of 3000K (or 2700K/4000K). Will that makes the light even more yellowish? Why not higher ‘K’ value (like the one for ‘neutral white’ 5000-5200K)? Does SST even have emitters ‘that high’?
Also, while I was trying to figureout why you suggested lower ‘K’ value, I thought maybe because it will not waste battery fast (since the light wont be as bright compared to 5000-5200K). Correct?

To make myself even more confused, couple of days ago it was some rainy weather in my area. I was walking the street after the rain and I come under those high (15-20 meters above the ground) street light. They were dropping yellow light (like the ones for ‘foggy’ weather), and the light was somehow ‘nice’ to look at. But then again, who knows how powerfull are those street lights (and probably not even using LED, but probably some ‘older’ technology). So I was like ‘huh’.

Another thing to mantion is… I saw someone using those foggy yellowish flashlight at flea market, and…they kinda looked like… (tooo dimmed), because everywhere around were those guys with high (neutral-white or cool-white) flashlight, and when their flashlight overlap the yellowish light from other people, you just see the difference and after the ‘high light’ guys move away, and you stay starring at that yellowish light, you kinda feel like you are left in the dark, if you understand what I mean.

Third question (this is a st*pid one): If 7135*8 and SST-40 are the drivers. What is biscotti? A firmware? Or ‘software’ ? You said Simon is working on biscotti for new drivers, so I guess you were suggesting I could pick SST-40 driver and ask simmon that it comes with biscotti? I hope I understood this well…

Fourth question (probably another st*pid one): In one of your previous posts, you said that SST-40 linear drivers have temperature control. I’m guessing its for protecting the battery from overheating? What if… temperature control fails? I know that I’m paranoid but… ofc I don’t want things to explode while in my hands. (though you said the lamp wont be warm if I use it at 30% (middle range)). I Guess if I use it at 100% with 5A current it will make everything supper bright and at the same time supper hot very fast?

Another thing that I read somewhere (someone posted it, maybe it was from amazon sales page, I really don’t remember) is that the lamp that he bought with dimming feature (which is what software do when your battery starts to drop voltage, I guess?) …he said ‘after a month dimming stopped working’. How that can be possible? And is the percentage of such ‘failures’ pretty high or low, in your oppinion? Don’t want to get in situation where I would buy a lamp and then because of software or (bad component) I’m left in the dark.

btw. does that SST-40 driver has an option to shut down the flashlight if the voltage drops at…lets say 2.9v or 2.8v ?

Another question: When it comes to emitter bins, there are tons of them, for instance: U2-1A, T6-3B, T6-4C, T5-5B, T4-7A. In this topic: Warmest tint for each bin there was an image posted. This one:

When I look at that image I can find 3B (from T6-3B emmiter), but what does T6 represent? (what are those U2, T6, T5, T4 ?) What are they?

2 offtopic requests/questions:

1. can you post (image or YT clip) how that flashlight from your nephew looks like? Or better, if you have that High CRI95+ SST-20 with SST-40 driver, can you please post picture/clip so I can see how that looks like?

2. You suggested Li-Ion rechareable 3000mAh battery. Which model (and brand, of those 5 major ones) should I buy? And is it correct to take protected one over ‘unprotected one’? I kinda want to secure myself as much as I can. (I’m guessing order from should be a good choice to buy from?)

Thanks in advance for your answer and sorry for this flood of questions.


I just checked site and (ofc) I got one more extra question: if SST-40 can take 5A, is buying a battery with 6.7A discarge current enough for that driver?
I mean this one: Panasonic NCR18650B 3350mAh - 6.7A

Also, what you think about these two:

Samsung INR18650-30Q 3000mAh - 15A
Samsung INR18650-35E 3450mAh - 10A

^ among reviews at site for those batteries, someone mantioned that he is a BLF member and that he bought 300 pcs already and is happy with it. So, I’m guessing they are good. Though all unprotected one. (not sure if ‘unprotected’ is what I want in my hands)

Just checked this one: LG INR18650-M36 3600mAh - 5A and in the description it sais:

And when I sort the search (at nkon website) by those who has ‘protection’ I get results with not a single one major brand (of those 5 major ones) among them. Well… fck. :frowning:

First of all, the Wikipedia has a good definition for CRI. It's not the only method of color rendering evaluation, it just is the oldest (and the worst) but still valid. You can for example check “TM-30-15 vs. CRI and the Future of Color Rendering” and “TM-30-15: A New Method for Measuring Color Rendition” (there are further methods too).

As human beings we are adapted to natural light sources: the Sun, fires, and blackbody radiators namely. All these “ideal” light sources have spectral power distributions which allow the average human being to properly discern color information. Light sources whose spectral power distribution differs from ideal make stuff look “less appealing” to us. Here are a couple of videos on this subject:


Also let me say that an LED diode “isn't good at showing the difference among colors” because it's us who, in our minds via our eyes (senses), do that in response to a natural or ideal light source. Some people don't like or need high CRI leds because they are “less efficient”, but this also is rigged or tampered way of looking at the matter because perceived brightness obviously depends on our sensitivity to the different visible frequencies. I don't care about efficiency, those who care can buy some green led and have the best efficiency, at the price of super wrong color appreciation.

Bins and tints.-

Emitter bin is a measure of the relative output an emitter has at its binning current. Thus, the higher bin the higher the perceived brightness. Take a look at emitter datasheets for more information.

Tints are a way to classify an emitter's light output within the color space. Examples:

This is the way Cree does it, same graph as you posted above.

And here is how Samsung does around 4000K and below:

This graph is from LH351B emitter datasheet, hence the 350 mA binning current.

The photos attached at the sales page don't really look like “the real deal”. They may look “sort of”, but take it with a grain of salt.

The reason I suggest “warm” emitters is because it is easier on the eyes to use a warm light source at night. When at night our scotopic vision is active, this is one of the reasons “warm” (what you call “yellowish”) light sources look good. And it also is the reason why “n00bs” wandering with “cold white” flashlights can easily kill your night vision if they focus their flashlights to you directly, it has to do with the amount of emitted green-blue light from their leds. With a warm light source at night you can easily see in the dark without having to turn off the flashlight and waiting for your eyes/mind to adapt.

Yes, Luminus Devices also has emitters above 4000K; and no, lower temperature light sources won't waste battery any less.

The street lights you speak about probably are low pressure “sodium vapor” lamps (colors look like crap with them).

What you say on the topic of foggy yellowish flashlight versus neutral or cool white, hard to say without really knowing what they were using. I have warm flashlights whose output is a good deal higher than most standard neutral or cool ones lumen wise, but the main reason for the phenomena you describe probably is the higher “night vision killing index” of neutral or cool leds versus warm leds.

Biscotti is a microcontroller software for flashlights which Simon uses in his 7135 drivers. Simon said he was working on Biscotti for the newer “SST-40” drivers in his [Convoy] thread. It is also called firmware, as it is microcontroller software written in “low level” programming languages.

The temperature control in the SST-40 drivers prevent the driver (and hence the flashlight) from overheating by reducing the current on demand (55 °C max). In high (5 A) the flashlight would become hot quite fast without temperature protection. It can be disabled by removing the onboard NTC.

Different flashlights implement dimming modes differently, but it has nothing to do with reliability. The amazon sales page torch probably was of bad quality.

Can't really say for sure if the SST-40 driver will shut down the flashlight below a certain voltage, but I would bet on it. Anyway, even if it were not to do it, it is a linear driver; this means battery voltage would hardly drop below 2.5 V even if left on unattended for days (the minimum Vf of standard white leds is close to 2.5 V, this is the reason). Thus, it is safe anyway no matter if you use unprotected or protected batteries.

U2, T6, T5, T4… are emitter bins. They define a relative emitter output at some given current and temperature conditions.

My nephew's flashlight is a green S2+ I custom built from a host with Samsung LH351D 4000K CRI90+ emitter and ∅17mm SST-40 driver. Had it at home recently but forgot to take pictures, sorry.

NKON is a great place to buy cells.

The NCR18650B cell isn't bad, but I'd buy Sanyo NCR18650GA (refurbished units available), Samsung INR18650-35E or LG INR18650-MJ1 (available refurbished) instead.

The Samsung INR18650-30Q is a higher discharge cell. I'd get it for higher drain flashlights (7+ A), although it is a good choice anyway.

The LG M36 is good too (and it actually costs a bit less than the MJ1, wonder why as according to Henrik's tests its performance is about the same as its sibling.

Oh! I don't think you need a protected cell, but if you do, KeepPower does it good without asking too much money (nice example).

Next time one question at a time, I've spent a loong while with this LoL.

Wed, 02/19/2020 - 04:43

WOW! Thanks Barkuti!

Its a deal. :slight_smile:

I’m sure more questions will follow. Just finished reading your answer and I’ll need some time for my brain to process the new information that you just provided. Thanks!

Edited my post to add a small clarification as to why battery voltage is super unlikely to drop below 2.5 V, even if left in a flashlight with linear or unregulated driver without protection. Generally speaking only boost drivers can be problematic, but any decent boost driver has low voltage cut-off for li-ion cells.

Happy it is of service.

Wed, 02/19/2020 - 06:07

Thank you so much Barkuti, for all your explanations :+1:
Thank you so much twist3r, for asking the questions :+1:
Thanks everyone, for sharing your knowledge :+1:
every newbie like me needs to read this thread, a lot of good info here.

Nice it is of help, BLF-L. Had to fix the write up of my essay, by the way.

I just received the S2+ red LED and selected mode works for less than 30 seconds before it revert back to default, on / off at full.