John
Buckner has given you some very good advice. The one place that may now have some exceptions is the use of the low self discharge NiMh designs such as the Eneloop's. They do seem to hold a charge nearly as well as the LiPo's do. I use them in all my transmitters now (and camera's) and they seem to hold up very well. I do keep a close eye on the voltages under load on the transmitters and so far I have gone as long as two months without having to recharge even with fairly moderate usage. I have Enelooops in my DX5, 6I, Futaba and Tactic and the batteries hold up well for long periods. The problem with Nixx batteries is that a voltage reading does not tell the whole story, the voltage can read quite high even with a nearly depleted battery. To guard against that I always charge at 0.1C for at least 10 hours periodically as that will insure a full charge and not harm the cells should they be nearly full when I start the charge. I do not trust fast chargers and use the fast charge only in an emergency as, if they fail you can ruin a battery with high temperature or if they false trigger, you wind up with not a full charge. You will always be safe if you use John's advice.