I'm not trying to be sarcastic(something of which I have been accused of around here lately), but Jet Airways
are almost exclusively, based on VOR's. That is, it is very simply, VOR navigation! If you want to get an overview of the airway system, buy a
high altitude flight planning chart. One thing to remember, if you're flying at the flight levels at mach .80, you will be traveling at around seven miles a minute! What this means is, you need to plan to LEAD a turn BEFORE you reach the VOR(you WILL find that in the AIM, section 5-3-5). And remember, at 39,000' you will be over six nautical miles above the VOR. You need to take this into account when referencing you're DME.
As far a 737 battery switches, if you don't get a timely response, try this; go to the members section top middle of this page, and find a fellow called Nexus 82. He's a bit of a 737 fanatic, and something tells me, HE probably knows the answer! ;)

.....so I loaded up the plane and moved to Middle-EEEE..........OIL..that is......