Luna G3 BPAP 25A/30VT DIY Power Cord

[CaveGimp]

Hello all. I'm a new user but not new to CPAPs or this board. I recently had a new sleep study and my doctor will be switching me to a BPAP machine. It will be a Luna G3 BPAP, not sure if it is the 25A or 30VT model. I go camping a lot where I don't have access to standard AC power, so I need a battery system. My previous CPAP machine was a DreamStation and I put together a 12V battery system, including a much smaller and lighter weight power cable. With the G3 it is a 24V system which isn't a big deal for me to convert my existing battery pack. My question is about the power cord and the connector itself. On the DreamStation cord I had to add a 20k Ohm to the center pin. Does anyone have the specs on the G3 power cord?

I know i can by a DC adaptor, but they are designed to be plugged into a 12V car plug and then boosts up to 24v. My goal is to have a 24V battery and not have the efficiency loss of boosting 12V to 24V.

If interested I can add info on my battery setup. The key with my battery setup is that it is ruggedized and waterproof so I don't have to worry about it too much in the woods.