The PH-Pro does have a battery, but if it were dead, how could Motley get the inidividual locos to respond following the reset. I am not so sure that his battery is dead, but it may be.
Regarding the consist kills, I was speaking from memory, so that is always dangerous.
But, I did not think that you could kill a consist until only the lead loco is left in the consist. I may be wrong.
The short/long loco address information is contained in the decoder memory. The consist address is also contained in the decoder in CV19. But the addresses in CV 19 are between 1 and 127. What the command station memory contains is the information as to what locos are in a particular consist. So let's say that consist 99 contains locos 456 and 457. If you select loco 456, this information is sent to the command station which looks up that loco 456 is in consist 99 and sends a signal to all the locos that are in consist 99 (as entered in CV19) and tells them what to do.
With NCE if you want those two engines to run, you can select either 456 or 457 and the units will run. You can also select, in this example loco 99, and both locos will still run. However, you will not be able to control any loco functions with address 99.
If the battery is dead, what the command station loses is the information relating to what locos are in which consist. However, when the system is turned on, the operator is able to run any of the locos because of the information remembered on the decoders. So the operator can enter either 456 or 457, set CV 19 to zero on both these locos, and they will run individually but not consisted until he reconsists them. The operator can also select loco 99, before setting CV19 to zero, and the two locos will operate together, consisted as before, because that address is still contained on the decoders. However, the command station will not know that 99 is a valid consist address. All it knows is that you asked for 99 to run, and it treats 99 as a short address.
In fact, at this point you could set up another consist 99 with two different locos. Then when you select one of the different locos, the command station will send a signal to the new locos (99) and they will run as well as the original loco 99's
The idea that the battery may be dead is offered as one posibble explanation as to why the consist information was originally lost. That may or may not be the actual case. If the system is shut down overnight and again all the consist address are lost, then that again points to the battery. If the consists are not lost, then something else has happened.
Regarding the killing of consists, I suggest that you try what I explained to confirm to yourself that the process actually works.