RE: giant lipo question :)
The term "C" is the amount of current a battery can supply in an hour. It stands for "Capacity".
A 2000 maH battery has a C rating of 2000 milliamp hours or 2 amp hours. It should be able to supply 2 amps continuously for an hour, or thereabouts.
A 5000 maH battery has a C rating of 5 amp hours. It can theoretically supply 5 amps out for an hour.
But you may be able to draw 10C or 20C or even higher out of the battery, depending on it's discharge rating.
Of course the more current you ask it to supply, the shorter the time it can supply it.
All this data should be available from the supplier of the battery you chose.