Batteries on GG-1 ?

I bought the issue of Classic Trains on the GG-1. I noticed on the drawing that there were storage batteries. What was their purpose? Also were there any special precautions needed to prepare the GG-1 before the pantographs were raised on a dead engine?

Control voltage, If there were no batteries the train would be in emergency each and every time contact with wire is lost

I've seen the picture in "Classic Trains," but don't remember all the details. How were the batteries charged? I assume there was a small (AC motored) motor-generator on board somewhere to feed DC into the batteries: is this right?
(You, Dutch, are too knowledgeable and too helpful for your own good! Answer one question, and your reward is... another question from the peanut gallery!)

The GG-1 had a sizeable MG set to supply the 72 volt charging power and normal control voltage including power for Steam generator and headlights.

Dutch--
Thank you!

All diesel and electric engines need battery voltage for many things; lighting, communication, control contactors, trainline control are some of the batteries duties. Older equipment used generators driven by the prime mover (diesel) or a M-G set tapped off a low voltage (600v+/-) winding of the main transformer to keep the batteries charged. Every builder had their own preference as to electrical gear and how it was applied.
Today battery chargers are solid state devices.

OK that makes sense.

Now for the second part. Were there any special procedures needed to raise the pans on a GG-1?

Thanks Dutch. You've been a great help.

I never worked the G's but the procedure for raising the pan is probably not too different from other electrics. The pans must be ungrounded by releasing the grounding lever. You need battery voltage to release the pan down latch, and on some motors air pressure to close the main breaker for the main transformer.
Once the pan hits the wire a start-up sequence gets all the auxillery systems up and running.