Isn’t it odd that after only 15 mins battery voltage drops to 3.3V ?
According to runtime graph after 15 mins in mid mode I would expect at least half of charge remaining, so 3.7V.
Maybe the flashlight drives LED harder than it should, but in this case you would face overheating. Or maybe both of your batteries have bad SOH.
If you measure battery voltage not immediatly after the flashlight’s shutdown, then the battery might have had enough time to recover voltage.
Welcome to BLF zujanzu 
sorry youre not getting the runtime you expect
my first guess is the problem could be due to the wrong type of battery.
- Are you using a rechargeable LiIon Battery? The light does not work right with non rechargeable CR123a.
- When fully charged what voltage does the battery show (how are you testing voltage)… Or, is the button light green or red when you start using the light?
- There are 5 modes, which one are you using?
I received the original battery with the lamp. The voltage of a full battery is 3.9v. I testing voltage with multimeter. I using all mode in 15 min when goes empty.
I hope we can help you get longer runtime
- Charge the battery completely, it should read over 4.1V
- use the second lowest output, to get there from off, hold the button until the light turns on, then let go
- now hold the button until the light gets just one step brighter. Then check if it only gives 15 minutes.
did that help you to get more than 15 minutes?
or, do you think the battery very old and tired?
1 Thank
it is not clear to me how all 3 batteries I have are bad.
One came with the lamp itself (sofrin), I thought it was next to it, so I ordered another 2 batteries from Aliex, but the same thing is happening.
Is it possible that the lamp itself cannot charge enough? I will try to charge it and keep it on low mode to see how long it will last.
And that it gets very hot, but there is also a warning that it is hot.
The table shown above shows how long it should last on turbo mode, and it probably won’t be close to 55 minutes even on low mode 
I ordered another 2 batteries
sofirn batteries?
Is it possible that the lamp itself cannot charge enough?
to test that,
the charging is full when the button turns green
then you can check voltage to confirm if the battery is taking a full charge, over 4.1V
it gets very hot
output is too high if light gets hot, test with a low output that does not get hot
1 Thank
It’s not a sofrin battery, a replacement one. I know when the green light is on that it is full. How long does it usually take to charge the battery? Does mine charge in about 30 minutes? Is this normal? I measured the voltage and when it is full it is 4.1V, it is not over. Is that normal? How long do your lamps stay lit?
thats good
I use very low outputs, for short periods, my HS10 does not get hot at the outputs I use.
I can not tell you how long the battery lasts when I use the light, because my low output and short interval does not empty the battery.
since you mention your light gets hot, I think maybe you are using a high output.
sorry I dont have more detailed answers to your questions…
it does not sound like there is anything wrong with your battery, my only suggestion is to try using a low output that does not get hot. Then let us know if the runtime is better.
1 Thank
Can you give me some kind of recommendation on which battery I should take that is surely good?
16340 is model
Tnx
I use the stock Sofirn battery. I dont think you need any more batteries. imo you need to use a lower output, that does not get the light hot. I hope you let us know if you get more runtime, when you use Lower Output.
But that is not even close to what is declared for that lamp. How can someone explain it to me? Bad lamp?
Can someone help me with what to do? Please.
You can check the battery voltage after the light turns off.
Charge all 3 batteries to full, measure voltage, and then use on turbo till it turns off by itself. then measure the battery voltage after it turns off. Do this for all 3 batteries. And share the voltages here.
Last weekend I received my first HS10 and conducted a test.
In middle mode the light was able to work for 1h 40m. The flashlight was still working but I decided to stop the test because the brightness had dropped to moonlight-like level and because I thought it had already overperformed the manufacturer’s claim (later I found out that I should’ve waited for 5 more minutes).
Somewhere at the 15th minute I checked the body temperature with IR-thermometer and it showed 40 deg.C. By touch it felt slightly warm.
After the test ending the battery had voltage of 2.76V.
So.
- The flashlight shouldn’t become hot when being used in mid mode. Either you are choosing the wrong mode or the driver is faulty.
- The flashlight shouldn’t stop working at 3.3V battery voltage. Either your battery is really bad (has huge voltage drop) or again the driver is faulty.
2 Thanks
Did you contacted Sofirn support?
Sofrin battery full is 4.004V, Testing is complete. It worked for 30 minutes on a Sofrin battery. However, after 10 minutes the turbo mode started to weaken, and the brightness was getting weaker all the time.
Empty battery is 2.764V.
It is nowhere near what is declared.
No, did you mean i must ?
4.004V is not a full battery.
If you are checking the voltage right after charging then the voltage should be 4.18-4.20. If your charged battery was left for a week the voltage might have been 4.13-4.15 but not 4.004.
Also it’s unclear from your last statement in what mode you have run the flashlight. Why did you mention turbo mode ?
I charged the battery via the hs10 lamp, because I don’t have a classic charger. It worked on turbo mode, but after about 10 minutes in turbo mode, the light seems to get weaker, and I have to press it again 2 times to start turbo mode. I hope you understand now.