Q8, PMS SEND TO THOSE WITH ISSUES BLF soda can light

I’ll take a look inside when I have some uninterrupted time in the next day or so.
I’m hoping that I’m in for one of those magic “take apart, put back together and it works great” deals.
If not, I may have to re-learn to solder.

Wow…. just wow. What I’m shocked about is that a brick & mortar retailer is selling absolutely dangerous crap like that. And a store called “Batteries Plus” should know that any 18650 with claims of 9800mAh is fake, fake, fake, fake.

Never go back to that store, except perhaps to demand your money back for them scamming you.

The double blink means the driver has power.

I’ve never heard of the light randomly turning on and off. I can only assume it’s something to do with those batteries.

Return the item for not meeting the specs. If they refuse, threaten to sue. It the still refuse - sue. You’re bound to win.

Thanks again for all of the responses. So the 30q’s have not improved the situation. I have charged them via the USB C included with the light. I hold the green button and light ramps for roughly two second and then quickly turns off. Like last time, no brighter than an out of the box $10 light from home depot. The light also still randomly comes on and off.

Any thoughts? Any experience on trying to return for an exchange?

Returning shipping to China usually starts at $60 plus there may be additional customs fees, so that is not really an option. Warranty related stuff would be them sending you a replacement head or whatever part is bad. It’s cheaper for them for you to keep the bad item.

If I had to guess, I’d say the FET is not working. Channel one uses a 7135 chip that allows .350mA to go through (about 150 to 200 lumen) and as you ramp up it switches to channel two which has the FET that provides all the higher currents.

I don’t know what could cause it turning on and off on it’s own, though.

Are you able to make a video of how it’s acting?

Are you sure it’s a Q8? Those don’t have built in charging.

As you suspected, it’s not a Q8. It is a SP36. If I’m in the wrong spot, let me know. The directions specifically cited this thread to get support.

I’m trying to upload a video. What that video displays is me screwing in the batteries and receiving 2 blinks. I feel like your hypothesis is directionaly correct. Instead of moving on to a higher power it simply shuts off.

I sent Sofirn US an email so hopefully they have some input.

Note: It’s hard to get a video of it turning on and off. That said I just saw it light up across the basement unprompted ha.

The SP36 driver is basically the same design as the Q8, but with a charging circuit designed in. It’s still a single 7135 chip and FET design. So what I said before still applies. If the FET is not working then you only get from moonlight to about 200 lumen. Some early versions of this light used NarsilM and later versions used Anduril. Unless I’m mistaken, both user interfaces use the same basic method of transitioning between channels one (7135 chip) and two (FET). As you ramp up once the 7135 chip reaches full output it stays there and the FET starts to add power.

So a bad FET would make it ramp up the 200 lumen and then just stay there. A double click to Turbo would shut off the light as that is the only brightness level that uses the FET only.

It definitely sounds like you have a driver problem, unfortunately the SP36 driver is glued in and not easily replaceable.

I would contact the store you bought it from to see about getting a replacement head or whole light.

I imagine you folks know this but I traded emails with Sofirn and they couldn’t have been more responsive and helpful. I provided a video and we tried some basic trouble shooting. In the end, they are sending out a replacement. Thanks again for all of the help here.

Sounds good.

Good going, Sofirn.^

So I finally managed to check the connections and everything seems to be nicely attached. I didn’t see any scorch marks or anything obviously amuck.

I decided to pick up another light to test and it won’t light either. I’m guessing that there’s a problem with the batteries or that I have two dud lights, which seems pretty unlikely.

I checked all four batteries on a meter and they all read around 357 or slightly higher.

Any better way to test the batteries without another light?

Any other ideas?

I’m thinking of picking up a new set of batteries but am trying not to spend a fortune just trying to get it working.

Hopefully I can get up to speed and learn a few things along the way.

Thanks everyone!

Do you mean 3.57 volts? That should be sufficient to light up, but not on the highest outputs.

Have you access to any other known to be working light that you can try a cell in?

Sadly, it’s the first (and only) 18650 light that I own.

I’m not even a novice with electrical. Computers, printers and gadgets, heck yeah but once it gets to the nuts and volts, I’m pretty clueless.
I was measuring DC and I think I had it set to 2000m.

What kind of battery charger do you have?

Are you inserting them with the correct polarity? Button tops against the big brass ring?

If you have a digital multimeter set it to DC voltage. If you have to choose a voltage range, use 10v to 20v. Verify it’s working by measuring some AA or 9v battery. Something you know is not dead. Fully charged they should be 4.20 volts or close. The lowest they should ever get is 2.5v. The Q8 flashlight gives a warning at 3.0v and will turn off power at 2.8v.

Any videos or pictures might help us. Your issue seems very strange so it might be something simple that’s being overlooked.

I think we are on different wavelengths here…. not sure you have the multimeter set for DC volts…. I have no idea what the “2000m” you mention is. Can you post a picture of the meter set the way you are using it?

2000mV FS, and if so, that means 0.357V, which is kinda scary.

No wonder it doesn’t turn on.

Move your meter to the ‘20’ setting for DC voltage and try again.

Here’s a quick guide to using a non ‘auto-ranging’ meter like yours.

I guess I’ve been badly spoiled by my autoranging meters. :person_facepalming:

Good morning!

I’m attaching some photos to help clarify.

Here’s a shot of the batteries positioning in the tube.

Here’s a shot of the driver/contacts.

And a shot of a battery on the (cheap) meter.

Also. I dont have a picture of it but I’m using a nitecore four slot charger.