obs does ps3 charging have the same problem the xbox controllers charging have? (introduces noise into the controller, and it attenuates a ton on the headset speaker & mic as feedback.) if you don't know can you check?
hmmmm if it's always trickle charging i'd be weary of using those internet lion's people are selling for them now!. veeeeery bad! that's potentially EXTREMELY bad!
nickle chemistry batteries (nicd AND ESPECIALLY nimh) do not stand up well over long stretches of time being trickle charged. it heats the batteries and they will eventually vent their electrolyte out of the battery. (even when monitored) it is especially common in NIMH because nimh has such a high internal resistance (that gets super worse as the cells age AND they discharge.).
also, modern nickle cells do not have the crazy high self discharge rates older cells had. (tho in all honesty, i would not surprise me AT ALL of 360 and ps3 both used old style cells earlier on)
FWIW, if you want to know how crappy the charging systems & their logic are on things like xbox 360/ps3. I have 10+ year old nicd cells still in service in one of my R/C aircraft, and a transmitter pack. their service is a million times rougher than what little controller's experience. that's the difference your average person/charger and the most advanced nickle battery charger this side of NASA (a rare Alpha PAL).