Backlit dx3s

[slimthelineman]

Not being able to leave well enough alone I decided to continue to heavily modify my dx3s transmitter by replacing the dry cell holder with a 2s 6.6v life battery today. Tight fit but after some massaging and removing the front lower screw tube it's in. Soldered a new pigtail with a deans to the power board on the back of the switch. Only thing I am wondering about is it's 6.6 volts now and I have the alarm set at 5.5 but fully charged the fully charged voltage will be 7.2. Should I only charge it half way? Don't want to fry the tx since it's waaaay out of warranty. Anyone got an idea of how much voltage these guys can take when they are supposed to run on four "aa" batts?