Sorry if this is'nt the right place to be asking this question, (if so could you guys lead me to the right place). I was gifted a wireless headset last year and it's been working great. 40 days ago i lost my charging cable and now that i have found it i tried to charge my headset and it would start charging. But even after 5 hours it did not get fully charged. My headset did not turn on and the instruction manual said that my battery needs to be charged. It's been 15 hours and my headset is still charging and wont turn on. Any help would me greatly appreciated.
It's the characteristics of some types of batteries that when discharged below certain point (voltage of cell below certain level) they refused to be charged again.
Replace the battery
More dangerous solution:
If you can get the battery out, use a multimeter to measure it's voltage. For charger to charge it, I think it should be at least half of its rated voltage. If it's lower you cant try 'boosting' it (some call it 'zapping'), just like you would do with a discharged car battery. This should boost the voltage high enough to allow it to be charged again. Of course if the battery is of some common type (maybe this headset has standard AAA batteries inside?) you can try charging it in another, more advanced charger.