And if you are using life batteries for your tx/Rx they can be left at full charge state in definately. It will not hurt them like it would a lipo. They are great replacements as their voltage is a little lower like 4AA for radios. And if you over charge them they will just spit out a black powder not catch fire. A little while back I saw a company that had military contracts for lithium based batteries. (Lipo and the sort) they had made a pack that could be shot, or have a nail driven into them and they did not catch fire or even die. They still made useable power. They would not however be able to be charged, kind of oblivious.
. Sometime in the future that technology will trickle down to us. Look on eBay if you do want to get longer balance leads, I hate that every charger company makes long charge cables but always manages to give you a short as possible balance cable!! And for any of you that use military ammo boxes for storing your batteries, good idea to drill a 1/2" hole in it (can put tape over it) that will let pressure out if lid is sealed, they can build up a lot of pressure when sealed up. Pressure = explosion. The hole lets it vent, if for some rare reason one decided to cook off.