I buy a Convoy S11 GT FC40 with battery on Simon store on Alie.
I have a problem when the lamp is at full power at 100% : Every 4/5 seconds it goes out and comes back on half a second later. I hear a little noise, a click each time it happens.
I tried to make a small video to illustrate my problem : https://www.youtube.com/watch?v=G6NIQA1sqHk
If anyone has any advice, I’m interested.
Thanks.
…a click each time…. so dont push the button !?
Nop, I don’t click at all. 
Sounds like low voltage warning. In mine it happened because of insufficient grounding. I cleaned all the contact surfaces with electric cleaner and that fixed it.
Thanks for the reply. It’s seemed not to work.
I’m talking with Simon but I’m no fluent and I have difficulty to translate :
Does it work normally, if you use the keep power battery?
Can someone explained to my what does it mean ?
Thanks.
Depending upon the protection circuit in that battery, it may not be able to deliver enough current to run the light. The protection circuit will shut down the battery output and reset after a bit… I think it resets, does not require a charger to reset.
In all of my FC40 lights I run unprotected cells to avoid this. Just like the little FWAA will trip protection on a 3 amp Xtar cell, put the wrong cell in a couple of times and it happens as soon as you get near high on the ramp.
If you do not have a good protected cell in 26650, like the older Lii or Kong cells, try with a 21700 cell. It not fit great, but will work for testing. I have little adapter tubes to use 18650 cells in 21700 and 26650 lights, they work great and you can get into some seriously good 18650’s that way.
are u using a non protected battery? maybe the protected is too weak…