mod? for lower battery drain on Atwood 7916-ii furnace?

Discussion in 'Boondocking' started by 2000skamperSPORTm17A, Oct 27, 2020.

  1. 2000skamperSPORTm17A

    2000skamperSPORTm17A New Member

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    The 16000btu furnace works fine in our 20-year-old Pup. But I wish it drew less current when boondocking with solar panel (& Group 24 Marine battery). This model has been around a long time...reliably in many RVs. So...I'm wondering if anyone has retrofit a more efficient fan/motor, etc.

    Ideas also welcome for replacing function of the really-hard-to-move ON/OFF slider on bottom of thermostat.
     
  2. Anthony Hitchings

    Anthony Hitchings Well-Known Member Silver Supporting Member

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    Add an extra on-off switch if it bothers you (its a truly aggravating switch). We simply replaced the entire thermostat with a new digital unit, located on underside of sloping roof above our bed. Just reach up and switch to "on" before getting out of bed.
     
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  3. Anthony Hitchings

    Anthony Hitchings Well-Known Member Silver Supporting Member

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    We have the same furnace in our 2003 pup. On our Aliner we have a 100W fixed solar on the front sloping roof, and a portable 100W solar panel, feeding two group 27 RV-Marine batteries from Walmart. We have had no problems getting enough solar energy so far except that in total shade sites like Yellowstone we used the second panel as portable (Jeep rooftop) with portable batteries and an extra charge controller in the Jeep. Then we used a DC-DC unit to move the energy from the portable batteries into our main batteries.

    I would not modify the furnace - its a fire-breathing thing, leave it alone or it may burn your house (Pup) down.
     
  4. 2000skamperSPORTm17A

    2000skamperSPORTm17A New Member

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    Appreciate this! If easily done, kindly reference the thermostat you have appreciated and the "DC-DC unit to move the energy".
     
  5. Anthony Hitchings

    Anthony Hitchings Well-Known Member Silver Supporting Member

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    LuxPRO PSD010BF Heating Only with Fan Digital Thermostat - from Amazon
     
  6. Anthony Hitchings

    Anthony Hitchings Well-Known Member Silver Supporting Member

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    https://www.renogy.com/12v-dc-to-dc-on-board-battery-charger/ was used, it is not fixed (not "onboard") so I can use it anywhere. I have an external fused "input" port on my Aliner outside wall for this purpose (other uses are alos possible).

    My DC-DC unit's wire harnesses are fitted with an SAE plug one end (for portable battery use) and the special connector on the other end (Aliner wall) - specific to my use for it.

    Update: DC transfer in progress for one of my two portable batteries - using the old wire harness setup.
     

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    Last edited: Oct 27, 2020
  7. 2000skamperSPORTm17A

    2000skamperSPORTm17A New Member

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    Thanks! Love the SAE plugs; use them to connect my portable solar panel to the tongue-mounted battery. You (& Renogy) are teaching me things about the DC-to-DC charging. They reference charging from alternator-energized starter battery. Your photo implies charge flowing between two static batteries; do I assume that the RNG-DCC1212-20 simply recognizes the better-charged (higher-voltage) INput battery, thus allowing flow until equalized? BTW - I like your taped "IN" and "OUT" reminders.
     
  8. Econ

    Econ Well-Known Member

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    @2000skamperSPORTm17A

    "Ideas also welcome for replacing function of the really-hard-to-move ON/OFF slider on bottom of thermostat."

    There is a little plastic tit that makes it hard to slide the switch to on. I think they did it on purpose. Attack it wiht a finger nail file. A little at a time til you like the result. Take the cover off and you will see it.

    On mine the on off is on the top not bottom
     
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  9. Anthony Hitchings

    Anthony Hitchings Well-Known Member Silver Supporting Member

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    The Renogy DC-DC unit has an INPUT (source) and OUTPUT (camper battery) side. It can be used with a car battery as a source, or an independent 12V battery bank that has enough charge. My source is a pair of Mighty Max 22AH batteries that are usually in parallel (using SAE-equipped harnesses). But on our recent three week trip to Utah, AZ, CO, NV we never used the portable battery system. We camped in the sun every time.
     
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  10. Anthony Hitchings

    Anthony Hitchings Well-Known Member Silver Supporting Member

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    I attacked the "tit" with Dremel after disassembling the entire unit. Even afterwards the switch was a PITA. Hence my replacing it with the Digital unit (which we love).
     
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  11. Anthony Hitchings

    Anthony Hitchings Well-Known Member Silver Supporting Member

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    BTW - after a minor meltdown on a trip many months ago, I replaced the harness cables. See attached photo.
     

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  12. Econ

    Econ Well-Known Member

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    Mine works like butter. You need the touch Anthony <GG>
     

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