Furnace and single battery

Too many variables to make a prediction. Depends on temp outside, wind conditions and insulation factor in the rv. All of these will effect the run cycle of the furnace. Add too that a factor for how warm you try to keep it. My 4-season trailer would struggle too make it one night with your battery with temps of 30 degree and 60--degree temp setting but I suspect the furnace is larger also.

JOLLERO - Just for comparison as to what MARKW8 says above..

My three batteries gives me 255AH capacity. I have a good DC BATTERY MONITOR panel that monitors both 12VDC from the two battery bank setup and a 75AMP DC Current from what is being drawn from the trailer items.

I usually draw 20AMPS DC Current from 8PM to 11PM each night running all the 120VAC items from a inverter and direct connected to the 12VDC terminals. In addition to this I have a good 1-2 AMP parasitic drain from the batteries 24/7. This will drop my three batteries (255AH capacity) to around 12.0VDC at 8AM each morning which is pretty close to being a 50% battery bank charge state. This is where I must re-charge by connecting my on board PD9260C converter/charger to my 2KW Honda Generator and run it for three hours to get my three batteries back up to their 90% charge state.

Perhaps you can judge from this what you 12AMP drain from your furnace 12VDC blower is going to do to you before 8AM the next morning.

What you don't want to happen is to drain your battery down below 12.0VDC without re-charging again. This will do internal damage to your battery unless you get it charged back up.

You can look at the specs of your battery to determine how many minutes it will produce 12VDC to totally drain your battery.

consider this spec sheet for a Trojan T1275 150AH 12VDC battery


The spec sheet says you can draw 25AMPS for 280 minutes before draining down to 0% Charge rate. SO running down to just 50% it will only last for 140 minutes or just over 2 hours of use. Your 12AMP draw using this battery should last 4 hours... Then you must re-charge back up to 90% right away before doing internal damage to the battery.

All of this is not exact but sort of gives you an idea on how to determine how long you can survive with one battery.

Roy Ken

Run a TEST while your still at home. JMO. I bet you have a GROUP 24 and that is near nothing to RUN DOWN.

I have a single group 31 Sears Platinum AGM in my TC. Can't remember exactly but 205-220AH. Not cheap but should do the job.

Mark

My furnace 12VDC blower draws around 6-8 AMPS from my battery bank. Thats much like leaving your truck headlights ON all night. One battery will not last long doing this haha...

The other problem is if you run your deep cycle battery down below 12.0VDC and not recharge right away you will most likely do damage to your battery and have to replace it.

I would guess 3-4 hours...

I was able to run four 85AH Interstate batteries across the tongue of my POPUP trailer between the propane tanks and the front of my trailer deck. I lost one battery right away before I changed to a better smart mode charging and have run the three shown in this photo for the past five years.


Roy Ken