Holding tank heater pads

[RLMcNew]

I have a 2017 Windjammer 3029W that has 12 volt heater pads. My question is, can I leave them on while attached to Tow Vehicle, and will the TV battery/Alternator keep the trailer's battery charged without damage?

I am headed down to south Florida next week and if the temperature stays as low as it is now, I am concerned that there might be freezing of residual liquid in the tanks. The rest of the plumbing system is winterized and will remain that way until below Dothan, Alabama. Thanks for any input.

[KenHwy61]

It sounds like your tanks are basically empty so if the residual water freezes it shouldn't matter. Just open the fresh water drain valve and rest will run out. Pour a little RV antifreeze into your black and grey tanks and they should be good as well making heater use unnecessary. To answer your question it depends on how often your tank heaters cycle on. They draw about 3-6 amps typically and turn on about 40 and off about 60 degrees. I don't believe the tow vehicle charges the RV battery very fast so the heaters may drain your battery it they are on for periods of time.