The 500w power inverter able to run overnight without significant battery drain in RV

I bought this 500w power inverter so to run a CPAP machine in our RV overnight while dry camping. The machine uses an AC power supply that outputs 24VDC, so I wasn't too concerned about using a pure sinewave inverter. The RV has two deep-cycle batteries on it, and the plan was to power the machine overnight and recharge the batteries the next morning. To help conserve energy, I turned off the heating capability in the CPAP machine, and also placed it in airplane mode. We were pleased to find that we were able to run the machine overnight, while also charging our 2 cell phones, and still have enough energy to keep things running until I got outside to crank up the generator. We were able to do this using the factory-installed cigarette lighter adapter near the TV console, which showed a rating of 8 Amps; no need for a direct-battery connection for this.

Haven't tried it with anything else, but this definitely satisfied our needs.couple months once I've really put it to regular use in the spring.