Hi guys, I just received my Trustfire TR-001 charger and some Trustfire 2400mAh Flames batteries from Aliexpress. When charging the cells with the said charger a loud hissing sound occurs, that I can hear it clearly at even 3 meters away. Is it normal? Any potential dangers could happen?
Unfortunately, a lot of the cheap chargers do that. I’ve never had one that caused any problems though.
any charger or any battery is a potential danger.
if you have a digital multimeter, measure the voltages of the batteries before and after charging, check for odd readings.
or just throw the charger away and get a more reputable brand like the nitecore/sysmax/jetbeam.
I think its the switch mode power supply in the charger
I have 2 TR001 since 3 years ago. All of them do that sound, I can hear it from 3-5 meters. No problem
Yikes!
I had a TR-001 charger like fran82 which I've handed off the one of my friends.
Squealed like a dying pig every time I chucked in a highly discharged battery, then after about 30 seconds, blissful silence.
No matter what brand/cost of cell. From cheapie blue labels to Panasonic NCR18650Bs.
Came to the conclusion that it was the cheap transformer/regulator in the charger that was at it's current providing limit, and the poor chip was being severely abused by cost-saving circuit design. Still hasn't copped out after regular use for over a year, though.
Yep, mine is the same, been doing it for 2 years now and still going strong [and still squealing lol]
Just ordered one of these [along with better batteries] 
2013 is the Year of the Snake…… Everything’s going to hiss this year!
Hiiisssssss.
My TR-001 doesn’t hiss … It is about three years old.
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My mom has a cellphone charger that does that, she used it too. But it works fine.
Good charger, only thing I hate about mine is how stiff the springs are. Sometimes getting 18650’s into it is a pain in the butt.
I now use these very cheap chargers for my 18650’s … I have four of them and have fitted a heat-sink to the back of the boards … The heat-sink isn’t essential , but it reduces the chip temperature by 15C and they were easy to attatch with special double-sided tape.
Suits me fine as they come ready to charge at one amp , so no need to change the value of a resistor to reduce the charge current … My Panasonic 3100mAh protected cells are charged to perfection using these … Certainly at least as good as the majority of other ready-made Li-Ion chargers … There is also the option to parallel two of these boards to increase the charge current if needed.
Highly recommended.
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Have you had your hearing frequency response checked lately? High frequency hearing decreases markedly with age.
Alright guys, after charging for about 1 or 2 hours the hissing sounds gone. I do not know how to explain this but I guess it is probably something to do with the cell’s remaining energy. I tried to charge my other cells and no obvious hissing sound anymore 
Should be fine, but I will watch it. Thanks for the input guys.
Sorry about the long delay in my reply to the above … Unfortunately we have had a bereavement in the family and I just haven’t had the time to check out the old TR-001 and reply properly.
Nowadays , I use some of those cheap charger boards when charging my Li-Ions … I find them particularly good for my use.
Anyway , I tried out my old TR-001 earlier today and it is still working as it should … Still charging OK … I still couldn’t hear any hissing from the charger … My Grandson could not hear any hissing either and he is 15 years old … I also checked with my medical stethoscope and still couldn’t hear any hissing … I can hear a heartbeat and can hear the central heating pump when the stethoscope is held against a central heating radiator , but absolutely no sound from the charger.
So all I can assume is that some of the TR-001’s hiss and some don’t … Personally , if I heard a charger hissing , I would not use it … Perhaps it is a sort of PWM noise as occurs in some torches or perhaps some models use a different type of voltage regulation to supply the charging section of the TR-001.
Again apologies for the delay in posting.
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So sorry about your loss, hope the you and your family will be filled with joy and peace again soon.
Well, maybe you got a good batch (have a theory that some components are driven to borderline levels and cannot support the current levels, hence some capacitance and electrical noise).
If you ever feel left out and want one that DOES make neck-hair-rising screeching, or sound like a tortoise being tortured to death, then I'll happily swap. :P