Fixing my 3 xm-l flashlight?

I have 3x XM-L flashlight with 5 modes (max,med,low,strobe,sos) uses 2x 18650 batteries.
The led driver on my 3 XM-L flashlight got ruined and now is a lot weaker then before and the max mode is as bright as the low mode used to be.
( led driver label says "hx-1150b" )

I was testing some cheap batteries i had, the driver would shutoff when the batteries got too weak.
But the last time i tried the voltage dropped to ~5.50volts and the current above 3amp before shutting off.
This time, after turning the flashlight back on the flashlight was very week.

The new voltage in the flashlight driver is ~7.93 high, 4.04 Med, 0.88 low. ( with no load ) ( and this voltage should power 3x xm-l led in series )
No idea what the voltage was before my led driver got ruined.

What went wrong my me led driver? can it be fixed?
Can i mod my flashlight and just remove 1 of the led? and run it off 2 led? ( accidentally broke 1 led anyway )
Or maybe replace 1 led with a resistor?

I am currently looking for a solution i can do now to use my flashlight,
i mean ordering a replacement led driver from DX will take weeks. ( i am guessing i need sku.57779 )

Thanks.

did you try it with a different set of batteries? is it possible you damaged the batteries by running them down too low? (i'm not really sure but i think that can happen with liions right?)

If the driver is a true constant current driver, you may have ruined it by measuring the voltage with no load. Many constant current drivers have to have a load to limit over voltage.

You ruined it through over current. This is a boost driver and it will pull more and more amps when the voltage drops to keep the output the same. If the voltage drops too low it will drain much too much amps and destroy itself.

Never ever measure the voltage of a driver without load. Most drivers will destroy themself because they dont have a no load protection. Also you were lucky that you didnt got an electic shock. Most boost drivers can get up to 80-100V without load.

yazovyet said:

did you try it with a different set of batteries?

Click to expand...

Yes, i tried it with other batteries, normally the flashlight would just shutoff with weak batteries on max mod, and would still work on med/low mode.

Genes said:

If the driver is a true constant current driver, you may have ruined it by measuring the voltage with no load. Many constant current drivers have to have a load to limit over voltage.

Click to expand...

Thought the flashlight driver was already ruined before i opened it to check the voltage at the driver.

The_bad_Frag said:

You ruined it through over current. This is a boost driver and it will pull more and more amps when the voltage drops to keep the output the same. If the voltage drops too low it will drain much too much amps and destroy itself.

Click to expand...

So the boost driver self destructed since i used batteries that for whatever reason lowered there voltage but were still able to supply 3A+ current?
I suppose better batteries would only lower there voltage when they were weak and not able to supply the current to destroy the boost driver?
Since the driver did have some sort of protection that would cause it to shutoff at certain times when the batteries were too weak to run on max mode.

I think what happend was that those 18650s had different capacitys. 1 of them was empty and dropped the voltage and the other was still good. That would be a reason for the high current at that low voltage. Undervoltage protections on some drivers only work in a defined voltage range. If the voltage is too low they stop working.

O.k. , this is my first thread !
Short and simple : Your driver is not " good for garbage " , is easy to repair it , I've done this for so many lights that I do not even remember...
Let's start ! The dimming of the light is coming from a deffective electrolitic capacitor , in your case , is the only one from your picture , with the value of 47 microfarads / 25 volts . I do not know why the chinese manufacturers are using this kind of capacitors in a device that is working in frequency and high temperature (as the one that is in the inside of a flashlight !!!).I suspect that is all about the cost...,you just have to replace this capacitor with a SMD type ,if is possible , with a non-polar one .You can find these on old non functional electronic plates or , better , new ones from electronic stores . Price ? Very cheap ,maybe 1-2 bucks..! You need to have some abilities to do that (because these are very small ,and has no terminals...) or you can ask a friend able to do this ..,once you replace the old one , your driver will come to life..!!! The best think of this is the fact that you can use almost any value around the one of the old cappacitor 33...100 microfarads ,even at smaller voltage , but keep in your mind :for 4,2 volts at least 6 volts ,for 8,4 V at least 12V , and for 12,6 V (3X186500 ) at least 25 V.That means that you have to see how many leds you drive ,in series or in paralel ,because if , for example , you have 5 to 9 Leds in series ,and 2 or 3 acumulators ,also in series , means that you have a step-up convertor that has to be able to supply your 5 Leds with about 18 Volts , or in case of 9 Leds , about 32 Volts !!!! Was just an example , but now is not uncommon flashes with 7 to 15 Leds !...,driven by 3-4 serial accumulators (Li-Ion...).

For the guys that has some knowledges in electronics : " the capacitive reactance of a electrolitic capacitor is dropping dramatic with the increase of the temperature and applied frequency ".
At this time ,when I'm buying a new flash light I'm opening up to the driver and replace the capacitors..,and never had this problem again ..!
Just give it a try , and you'll see...Good luck !