"By the way, not all CPAP machine situations require "strong" batteries. Both my and the DW's CPAP machines use no heating, so their coach battery drain is very low. We don't need fully charged batteries at all for both of us to easily make it through the night with two CPAP units running"
I can attest to the fact that when a BiPAP humidifier heater is heating, it imposes a 500% increase in amperage. Cold nights in the 50F range may mean the heater is seeing 100% duty. Four point nine two amperes for a Respironics unit.
Unfortunately I need a humidifier.