The C figure is a function of the battery pack's capacity....
Example: If the pack has a capacity of 3000mah then the charge rate would be 1C or 3 amps using a constant current charger...Now the charging regime for lipos is CCCV which is constant current until the pack reaches a predefined voltage(this setting is down to the charger circuitry) then the charger switches to constant voltage mode until the endpoint of 4.2v/cell is reached, during this time of course the charge current is always decreasing...as the battery voltage reaches the 'fully charged' value.
Discharge rates vary with packs...Some you will see are rated for 15C, 20C and 30C. There maybe other values but these are the most popular...
This mean that for a 3000mah pack rated for 20C discharge, the max current you can pull from the pack would be 3000*20 or 60 amps!.
When using lipo packs, it is wise to use some sort of low voltage detection circuitry to cut the power to the load to prevent over discharging the pack. This voltage is usually set to aroind 3.0v/cell as a maximum..dont go below this or you may find the pack be irreversibly damaged...Some chargers axctually detect the pack voltage before commencing the charge cycle, if the voltage is too low they wont charge!!
Hope this explanation helps to clear away some of the mystery....my choice of words may not be the best..
Looks like the 'A' clips are for connecting to any type of connector furnished on a pack