I mentioned these a year ago, and many folks here said I was nuts:)
No problem, but I've had one on my sailboat now for a year, and LOVE it. Much easier than pumping/cleanout stations at the dock.
They use almost no power, the one on my boat is powered by a small solar panel.
By the way, Tiger Adventure Vehicles, which makes some of the finest, most durable off road truck campers in the world offers one.