For battery start: Hold the APU start switch all the way down to START position. After it releases, go up to your electrical panel and note the current draw. The APU starter should be drawing about 250 amps. This means that the APU start sequence has begun. After a few seconds the LOW OIL PRESS light will illuminate and extinguish. Once the egt temperature has stabilized, you can connect the APU generators the tha aircraft bus. If you want to be nice to your battery, attach the external power cart.