You will be fine with the 1500mah battery using 5 analog servos.

Digital servos draw quite a bit more current out of your battery as a personal rule of thumb if I'm going to use more than 4 digit servos I do a couple of things to my setups. One I go to 6 volts vs using 4.8 and secondly increase the battery's capacity to the over 2000 mah.