I bought my first RoadPro 12 volt water heater for my Prius Hot Water Heater for my first Prius Travels in 2015.
I have heavy duty wiring and fuse on my Prius 12 volt battery system to power this water heater for my Prius. I only use the RoadPro with the Prius in "Ready Mode" to not stress the Prius battery as the AGM battery in "Ready Mode" is fed from the Prius high-voltage battery and the engine keeps that charged in "Ready Mode". Therefore, I don't drain my Prius 12 volt battery. Note: The Prius 12 volt battery does not start the Prius engine, so it is relatively small, since it is designed to power the Prius electronics.
My RoadPro hot water heater died just before meeting with family on my travels to Utah. This unexpected death of my hot water heater boil water with my stove.
I find the RoadPro Hot Pot handy to heat small quantities of water rather than getting a pot and stove out to heat water. If in cooking dinner, then the pot and stove is fine.
For my last leg of my 2016 Travels I stopped at a Pilot Truckstop and I bought a new RoadPro water heater. They cost around $24.00.
Obviously, I would not buy another one if I wasn't happy with its functionality. I use it hand and hand with my 24 hour Thermos to store the hot water until the next day.
If you are considering a 12 volt hot water heater the RoadPro is a good choice as long as you know it can't be put in water and there it is plastic. Also you should have a dedicated heavy duty 12 volt outlet like what Blue Seas sells with heavy dedicated wiring & run you vehicle while using.
If I had my stove set up for use all the time then the RoadPro would not be as necessary.
It takes about 20 minutes to rapidly boil water with the RoadPro.