So let's say that I'm building a cleric. Channeling is charisma based, with daily channels equaling 3+CHA modifier. Usually a minimum 1 follows such dailies.
If my charisma is 5, do I only channel 0 times per day?
If no minimum is specified in the ability description, then you'd be unable to channel while your Charisma was that low.
With charisma of 5 channel energy should be last of your concerns.