RAT generates electrical power hardly enough for AC ESS and DC ESS busses (not SHED busses), and BLUE HYD SYS. Battery is meant as the last mean of supplying power to the a/c while in EMER ELEC CONFIG so had better not to be used for an APU start attempt. A second RAT surely can't be the solution, otherwise it will be necessary to install another EMER GEN and its own GCU, thus significantly increasing the aircraft weight, also keepin' in mind that a RAT can stall and must be in the right place ... just my thought !
