i should make a video where i overcharge one of my batteries??

I have closed the Ticket, what should i answer. maybe this is what they want with videos

I gave up the whole story, looks like there is no answer from FT else then taking a video while overcharge, so i have closed the ticket before it makes me angry.
not worth the 6$

I agree with you, it should not be done in an uncontrolled way by someone who have no ideas about the risks it involve.

Since we are on batteries safety discussion.

What will happen to the battery are greater capacity loss than normal and greater potential for overheating during that specific charge.
It will not render the battery useless if it does'nt overheat and vent.
But subsequent charges might require that the CC be adjusted down for that battery, so that the CC stay within the C charge rating of that battery base on its actual capacity.

Even with normal wears and tears the capacity should be monitored, and the CC be keept within the battery C charge rating according to the battery actual capacity.
Batteries should be discarded as unsafe to be charged in that charger if it can't adjust the CC suitably.
Failure to do so pose more risks than trickle overcharge do as more current = more heat generated.

No matter the charger used, never leave the batteries in a charger for long period of time after the charge is completed, and monitor your batteries capacity.

What is the CV open voltage at the battery terminals of the charger, without a battery in it ?

There are lots of chances that it is the trickle circuit itself that is causing the problem, due to inrush current.
But If CV can be measured and the open voltage is > 4.35V you will have the proof you need.