i wired a 12 volt plug by the bed for my CPAP machine. Used a "cigarette lighter plug" used it for the past 12 years no problem, no batteries. Order most supplies from Apria health care if they did not have what I needed I made the item.
I got the battery. The rep told me the solar charger needs to be in direct sunlight to charge properly. If you get both I would email and ask for a bundle deal. They took 10% off of the battery and unit for me.. saved me close to 80 bucks. Never hurts to ask.