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?
The funny thing is that I have a nice autoranging meter and just can’t find where I put it.
I (with the help of a good tutorial) was testing a couple electrical outlets back before Christmas.
I guess it’s good that I have a cheap backup.
I’ll change the settings and report back in a bit.
0.35V basically means that your batteries are dead, too much discharged to be considered safe, even if they do charge up again.
I wonder how that could have happened inside a Q8? When the light is switched on it has a low voltage protection and will shut off with the batteries still at 2.8V. When off, the green indicator light will drain your batteries lower because of the small drain/MCU not powered, the LVP will not work (at least that is what I have understood), but that green led uses so little power that it should drain the batteries in years, not weeks.
battery at 0,35V ? wow… that is kinda insane low… all individual give those kind of readings ? thats not even half a volt if thats true…. i havent seen anyone post such a low voltage….
I wonder if those batteries are even legit and not some garbage cells…
Really toss these batteries its just dangerous to try them in a light and turn them on, dont charge them either!
Unless you used the batteries in some device that ran them way way down, you recieved bad cells. You should contact the company you bought them from and explain that they never worked and you just now bought a multimeter and measured their voltage at 0.35v so they are ruined. See if they will send you replacement cells.
The first thing you should check when buying new batteries is the voltage. They usually get shipped around 3.4-3.8v. Never fully charged due to airline safety rules. If they arrive to you below 2.5v then they are ruined. Once a lithium ion cell goes below 2.5 volts it forms crystals inside which screws up the chemistry. If you put it on a charger it can get dangerously hot and possibly vent or catch fire. So mark those batteries as ruined and don’t use them. It’s not worth the risk.
If you dont have a warranty, usually Banggood has good prices on button top 30Q. I got 4 for $20 shipped a year ago, but at the moment they seem to be $29 shipped.
Illumn.com has them locally for $22 plus shipping.
IMR Batteries has them for locally for $24 plus shipping.
Oh wait, I see your earlier post where they did work, but now they don’t. I’m guessing they got drained while in the light. This should definitely not happen unless you have a defective driver.
What you need to do is measure the parasitic drain on your light. You do need at least one proper battery to do it so this may have to wait till you get one, but here is the whole procedure.
Basically you can use one cell and hold it on the head like this similar light.
You keep your test leads in their current meter spots which is COM and V Ω mA.
Then set the dial to the green DCA section 200m. Apply the test leads to connect the ground side, but leave the flashlight off. The light should blink twice, then wait about 5 seconds and it will go to sleep mode. Then you can get a reading. Assuming it’s not overloaded, you can switch the dial to the next 20m then 2000μ and then 200μ. Normally this light measures about 30μ when asleep (green switch light off, with green light on about 130μA) which is super low amperage. Since you might have a big drain, we start at the higher 200m setting and work our way down.
It’s pretty rare for these lights to have a big drain, but they do happen from time to time. If both your lights check out fine, you might have had one bad battery which was self discharging. Since they are all in parallel, one bad cell could pull the other three down. This is also pretty rare. 30Q are very high quality cells. Still, something happened and we need to find the source of the problem.
I have a flat top Samsung 26FM and since I’m holding it in place, thought it would work for the test.
I get –08.7 on the 200m setting on my old light and –05.6 on the new one.
Why risk ruining 4 new cells? It’s pretty easy to measure parasitic drain. Then you know if there’s a problem or not.
I wonder if the person sold it because they knew it had a drain problem? Maybe. If the driver is bad, you can get another for $10. To swap drivers requires soldering 5 wires.
If you can’t solder, well, another option to “fix” it is to just twist the battery tube when your done using the light. This cuts all power. It won’t drain at all. This is the best way to store a light.
