How does a Convoy signal low battery condition ?

Hello BLF,

My S2 has goes thru lo, me, hi, blink, sos. I run it in lo, med, hi mode.

When the battery goes low, It shows change of brightness ( aflickier)

and turns off immediately. This makes it difficult for use outside in the

mountains, to suddenly be in the dark. I like them alot, gave one to my

grandson. Now to get a replacement, and looking at an S21 type model

or a Z1 (21700) with 12 groups. In find different specification for battery

charge indication. How does it actual display battery charge? Is it going

to be the same for all Convoy flashlights which have the 12 modes? Is

there more than one way to access this?


5 blinks for full battery, 1 for low. You can only access battery check in some groups that include strobe, unfortunately. I think it’s the same for all 12 groups drivers.

Thanks lfb,

In one information page it states:


1.The speed of half-press should be fast

2.flashlight flashes once per 6 seconds at low voltage (3V or so),and shut down later

3.No temperature protection management,pls pay attention to the heat,

On this convoy page it makes no such statement.

Have a second flashlight on you.
These are Chinese no name flashlights, they are not high end, certified, robustly designed life preservation devices.

That said you should test the light at home with a timer so you know how long each mode lasts with a full battery. And owning a light with low battery warning before it blinks out is a good idea.
In the prepper world they say two is one and one is none. The idea being that you want backups for anything important in a survival situation.

I have had Convoy lights experience Gremlins at the worst times, no idea why. I’ve had one permanently fail.
They are great lights and i actually plan to buy two more in the future (M21B and H1 are on my shortlist) but i always bear in mind their strengths and weaknesses.

10+ years ago when lithium batteries were replacing nimh and nicd, they were criticized by many people for quick drop off in voltage/power.

The contractors liked the nicd batteries because even when the battery was 60% depleted, it would often times keep running to drive that last screw.

Flashlights using alkaline as well would become dim and stay dim for a very long time.

There are certainly tradeoffs with anything, but personally I would never go back.

I recommend that you buy directly from Simon at the Convoy flashlight Store: Convoy Z1 zoomable flashlight.

He will have the latest hosts, drivers, and firmware.

As you can see on the website it has temperature protection and battery check. The battery check function is the same for all the Convoy 12 group drivers.

Battery check instructions:

  • less than 2.95V 1 flash,
  • 2.95-3.25V 2 flashes,
  • 3.25-3.55V 3 flashes,
  • 3.55-3.85V 4 flashes,
  • greater than 3.85V 5 flashes

I have a few Convoy flashlights. They all have a low voltage protection keeping you from over draining a Lithium-ion cell. What I find with these in the higher modes as the voltage sags it drops down a mode. If on high you’ve cut a couple of lower modes as steps before it cuts off. Your S2 light is a good light with relatively lower battery drain. Your best cells are the Sanyo NCR18650GA 3500mAh or Samsung INR18650-35E 3500 mAh. These two batteries will meet any current demands even on it’s brightest setting and give you hours of runtime on lower. Something like this to carry a few spares. IMRbatteries EVA Case - IMR Batteries

I think it must vary on different drivers from Simon. You are wanting to know the low voltage protection behavior and not the battery check behavior. I don't know what it's like on the newer 12-group drivers but I'm sure someone can tell you exactly, or you could send a message to Simon directly (here, or at his aliexpress store that NeutralFan linked to). I just received a couple of the 12-group but won't have them installed for a little while. I think my older Biscotti drivers gave the blink and that lasted for several minutes before the light shut off and definitely dropped down mode levels beforehand. This may depend on the quality/health of your battery, too. My most recent T2 light has a 4-mode and it does the same blink behavior as what I remember with the Biscotti except the light seems to gradually dim rather than step noticeably.

I don't know if the Z1 had many changes but sometimes Simon will add options or discontinue others, and then the product page disappears for good along with the description he gave. So a current page may have different information applicable to the current version. With other sellers that have his lights for sale, sometimes they only copy old descriptions and don't change that even though the light may have changed..then you get a surprise when you receive it. Banggood is often guilty of this failure to maintain/update descriptions. The sellers you linked to don't seem to be doing the simple copy/borrow thing, though. Just something to look for if you aren't buying from Simon directly, and I know it doesn't help you with what you want to know right now, sorry. :)

Also, have you already checked the basics such as clean threads, no debris, snug retaining rings in the head and tail? Often these things create odd behavior.

Thanks for the response. My use is more casual, but do live in the mountains, It’s dark with no moon light. No su much as survival equipment, I have thought about timing how long it runs. It is my first convoy, no from Simons store. The rest will be from his store.

Thanks zoulas, looks lie Maglite stills rules in some ways. They do dim slowly, no fast shutoff. I have a few around the house to grab when power goes out unexpectedly. It does several times a year.

Thanks NeutralFan, thanks for pointing that out. I can see that on Simon store. Good to know it applies to all 12 group driver.

Texas shooter, I have do have the low voltage cutoff, It only gives me about 1 second warning. As it is my first Convoy, I did not know to get it direct, so it could have older firmware.I am only using Panasonic and Samsung cells. With tested full capacity from my battery analyser. Carrying a spare, I have the plastic carriers.

Now I like the step down in brightness you describe, While in use, if I get 1 minute + I would be happy, Seeing it step dimmer, as the battery lowers voltage would be excellent. So, am I understanding this correctly?


Hello correllux,

I would be pleased to get that. I get a wield double/triple twiddel and then its OFF in less that a second. Battery is actually low, measured on voltmeter. I purchased on amazon, before I knew to by direct from him.

I have two, they behave the same. One is only a few months old. very clean. As I have checked the battery voltage, they are low. It is the biscotti 3/5 mode. I may consider upgrading thee driver board to new 12 mode board.

Thanks for the response.

If you already have a battery analyzer you’re ahead of the curve. Step down low voltage as I understand it. You’re running high at 3 amps and the fresh 4.2 volt battery dips to 4.0 under that load. When it depletes enough to hit say a 3.0 volt cut off it steps down now on a lower mode only drawing much less current. Now that 0.2 volt dip might only be 0.1 and the battery spring back up to 3.1 volts. You now have some more cushion until it drops to 3.0 again. Problem is lower current loads have lower voltage sags so that cushion gets smaller and smaller. So if it’s dropping out of high it’s time to change the battery.

Doesn’t have to be survival, a spare light or at least a spare battery plus knowing how much runtime to expect still helps you out.

Just a data point here: I let my T2 14500/AA run all the way down. Removed the battery to test voltage at several points (quickly, so it didn't have time to rebound). Right at 3.0V it gave a three-blink warning. At this point light output was already noticeably reduced and you'd want to be charging the battery anyway, probably. Another 15 minutes of runtime on high (much reduced, probably equivalent of the 2nd lowest mode on a full charge) it was 2.95V. Continued on with reducing output for about another hour and fifteen minutes and hit 2.81V and at that point it was close to a moonlight mode and the light shut itself off. Each time I reinserted the drained battery it would give the three-blink warning, but it apparently will only do that one time in normal operation. So it's not a nagging alert and there is a very long amount of "emergency" run time before it shuts off, albeit with very little light left (but a good half hour or so at least).

This is a newer and different driver for Simon as he has revamped many of them over the last year or so. I normally don't let my batteries go down that low but I'll try to do so with my old Biscotti and the newer clone 12-group drivers, and the M3 driver, and see how they behave.

Hello Correllux, Thanks for your responses. I have sent a message to Simon.

I noticed on the Convoy store, in the description for a M21B, the following (partial)

Material: Aluminum Alloy
LED: CREE XHP35 HI with DTP copper plate
Driver: 4 modes 1–10–40–100
Low voltage warning: Yes <<<<<<<< This text not in some other flashlight descriptions.
Reverse polarity protection: Yes
Lens type: ar-coated glass

This text occurs on some 12 group Convoy flashlight pages but not on others.
I await his response.

I appreciate your response on how your T2 steps down in brightness, that would fine.

Simon PMd me,

Convoy are certified :slight_smile:

Found out Astrolux/Mateminco have no certification making them illegal to be sold in many countries :frowning: found this out after importing $3K stock. Absolutely useless for such a big brand to do no safety testing

If it only has 3/5 mode, it’s not biscotti. :slight_smile: