Winter Tank Heating

RCB

I don’t understand why one would use12 volt tank heating pads. Apparently they provide some heat, but they must drain the batteries. Why could not the Alde be extended to heat the tanks?

Sharon_is_SAM

There has been at least one owner who has extended the Alde glycol runs to keep things from freezing.

DougH

@RCB As mentioned, several here have done the Alde extension.  I didn't feel confident enough to do that plumbing and fabrication, and wanted to not use that much propane, while also having some protection on the road when propane is discouraged, so I just did the 12V pads and heat trace cable.  And yup, they sure do drain the batteries.

I have up to 50W cycling on the fresh and gray tanks (each, but thermostatically controlled), 25W on the black and gray drains and valves, and 25W on the fresh tank intake lines.  Often I don't use the fresh tank when winter camping if bitterly cold, so I can cut my use to half that amount.  I also have a bunch of thermocouples installed everywhere so I can monitor if an emergency winterization is needed when it's consistently below 0F.  So far I only snow skirt when winter camping.

I used to have a PWM controller on each of those four circuits so I could just trickle in the power to keep everything barely above 32F, but I recently transitioned to just plain on/off switches. Though a couple folks on this forum have pointed out that with the thermocouples already in place I could have bought a multiline digital controller to automatically provide the perfect amount of energy to keep everything thawed. A little expensive of a solution, but a huge savings on the battery drain. 

I often use the pink stuff and emergency winterizing before hitting the road, so I can cut 12V power requirement to zero if needs be.  

But regarding battery drainage for dry camping...  with 2500Wh of battery and 300W of solar, I can barely keep up when I'm getting good solar (Victron reporting over 1000Wh incoming per day).  But I can't use many inverter 110V appliances when boondocking with all the 12V heating on (aside from the mandatory morning coffee).  When on shore power none of that matters of course, and I just need enough gray tank and black and gray drain heating to drive to the closest dump station if not using any pink stuff in the drains.  And I've got enough solar and battery for that, assuming there's a dump station within an hour's drive or so.

DougH

@RCB I think gregp was one of the first on this forum in recent times to document his Alde extension:

   https://tab-rv.vanillacommunity.com/discussion/comment/106149#Comment_106149