I don't use a CPAP but read a ton of reviews on these things and CPAP always comes up. I have a v2 Explorer 1000 by Jackery and a smaller unit from NinjaBatt. Both will easily accept solar panels and there's no reason not to bring a panel, it helps. I've used the smaller one quite a bit with a cheap Renogy 50 watt hard panel, actually use it's shipping box to pack it around and it works great protecting it. The Jackery I have two 100 watt panels but usually only bring one unless I know I'll really be hammering it. Last trip on a barrier island down here in the winter with overcast skies it ran my 12v cooler and pellet grill for 5 days as well as charging phones and headlamps with a single 100 watt panel giving it a bit of a boost through the clouds. The Jackery I recall plenty of reviews mentioning it works well for their CPAP. No matter what you get, get some extension cables for your solar so you can position the panels optimally. If you're in camp you can move them around to keep them optimized with the sun or just face them South at a 45 degree angle (exact position depends on location) for an all day best use. You can of course DIY all these things, they're just a battery with an inverter and a bunch of plugs wired up, but the packaged units are nice to have and I like them for easier packing and setup.