Heating system failed while plugged into 30amp service

[azric]

While in 15 degree weather this fall in Colorado our heating system failed in the middle of the night. The 2007 Forester class C was plugged into a functioning 30amp outlet. All 120V appliances continued to work, but all 12 volt appliances were failing. The heater fan would not stay on, thus no propane heat. The battery meter in the coach showed very low. I believe it was the fault of the factory installed 12V heat pads on the black and 2 grey tanks which were turned on that evening.

The next day, I turned off the heat pads, and everything came back to normal in a few hours. The batteries are new and we experienced no other issues the entire rest of the week long trip.

Has anyone experienced this type of issue?
Could it be that the converter is not able to keep up with the heat pads and the furnace at the same time and I need a larger converter?
Any help is greatly appreciated. Thanks.

[Bama Rambler]

The converter should be able to keep up with the heating pads, furnace and all the lights without a problem. And it should keep the batteries charged.

It could be that the thermostat for the tank heaters is stuck on so that they stay energized all the time. There also could be a problem with the converter so that it's not putting out the rated power.

What is the brand and model of the converter?
Also do you know the model of the tank heaters?

[donniedu]

I guess to answer your question you need to add up all your 12 volt current draw. The converter will only put out what its rated for. If your draw exceeds what the converter can put out your battery will go dead.

[Cypressloser]

Is the charger even running, do you hear the fan in the back of the converter box?
Can you connect a multimeter and measure the DC output, because under normal circumstances the converter should run the stuff and not the batteries.

[azric]

Thanks everyone for your replies.

The power converter is a WFCO WF-9855. It is a 55 watt converter.
The three heat panels are UltraHeat TH-718. They consume from 3-6 watts each.

Since this was the middle of the night (approx 2am), and we were only using the heat panels (18w), the furnace fan (5w?), and possibly the water heater (15w max? - if it actually kicked on), the converter should have easily been producing enough watts (55) to run all of these (38 watts total). Charging the battery may also have needed to be done so add another 10w(?) = 48 watts total.

After talking to the WFCO and UltraHeat people they wonder if the UltraHeat panels are connected directly to the battery and NOT the converter. Do any of you know if Forest River direct wires these heat pads to the battery? This would explain the batteries going dead since the converter couldn't charge the batteries fast enough to allow the heat panels to do their job.

Also, the heat panels do cycle power at 44 and 66 degrees F. But since I had drained all tanks and only left a small amount of fluid in each, this causes the heat panels to cycle continually using more battery power. Better to leave black and grey tanks half full in cold weather according to UltraHeat.

Bottom line so far: if the UltraHeat panels are connected directly to the battery and NOT the converter that is probably the issue. Otherwise, back to the drawing board...

[5picker]

Originally Posted by azric

Thanks everyone for your replies.

The power converter is a WFCO WF-9855. It is a 55 watt converter.
The three heat panels are UltraHeat TH-718. They consume from 3-6 watts each.

Since this was the middle of the night (approx 2am), and we were only using the heat panels (18w), the furnace fan (5w?), and possibly the water heater (15w max? - if it actually kicked on), the converter should have easily been producing enough watts (55) to run all of these (38 watts total). Charging the battery may also have needed to be done so add another 10w(?) = 48 watts total.

After talking to the WFCO and UltraHeat people they wonder if the UltraHeat panels are connected directly to the battery and NOT the converter. Do any of you know how Forest River direct wires these heat pads to the battery? This would explain the batteries going dead since the converter couldn't charge the batteries fast enough to allow the heat panels to do their job.

Also, the heat panels do cycle power at 44 and 66 degrees F. But since I had drained all tanks and only left a small amount of fluid in each, this causes the heat panels to cycle continually using more battery power. Better to leave black and grey tanks half full in cold weather according to UltraHeat.

Bottom line so far: if the UltraHeat panels are connected directly to the battery and NOT the converter that is probably the issue. Otherwise, back to the drawing board...

Doesn't matter.... the converter is connected directly to the battery too.
It's the same result.

Everything that is 12v is somehow connected to the battery and the converter simply supplies a supplement to the battery (when plugged into shore power) and to keep the battery charged.

[Bama Rambler]

I would check (or have checked) all the connections in and near the 12 volt power distribution. Especially between the converter and battery. There have been plenty of reports of loose connections in the 12 volt as well as the 120 volt systems in these rigs.

[Granny K]

There are lots of threads expressing concerns about batteries failing and whether the battery is being charged by the converter. Problem is, without actually measuring the state of charge, charging rate, current draw etc. it is difficult to know exactly what's going on..

This winter I bought a "coulomb counter" type battery monitor on the advice of the folks at RELiON who supplied the batteries. http://bit.ly/2iU03Rv

With it installed, I should be able to tell the battery state of charge at a glance, see whether the converter and generator are working, measure current draws etc. We'll see how it works boondocking next year.

[Cypressloser]

Originally Posted by azric

Thanks everyone for your replies.

The power converter is a WFCO WF-9855. It is a 55 watt converter.
The three heat panels are UltraHeat TH-718. They consume from 3-6 watts each.

Since this was the middle of the night (approx 2am), and we were only using the heat panels (18w), the furnace fan (5w?), and possibly the water heater (15w max? - if it actually kicked on), the converter should have easily been producing enough watts (55) to run all of these (38 watts total). Charging the battery may also have needed to be done so add another 10w(?) = 48 watts total.

After talking to the WFCO and UltraHeat people they wonder if the UltraHeat panels are connected directly to the battery and NOT the converter. Do any of you know if Forest River direct wires these heat pads to the battery? This would explain the batteries going dead since the converter couldn't charge the batteries fast enough to allow the heat panels to do their job.

Also, the heat panels do cycle power at 44 and 66 degrees F. But since I had drained all tanks and only left a small amount of fluid in each, this causes the heat panels to cycle continually using more battery power. Better to leave black and grey tanks half full in cold weather according to UltraHeat.

Bottom line so far: if the UltraHeat panels are connected directly to the battery and NOT the converter that is probably the issue. Otherwise, back to the drawing board...

Your converter is 55 amps, not Watt.
12 Volt x 55 amp = 660 watt
The converter may be feeding a dead battery, check the fluid level and do a load test.

[azric]

Originally Posted by 5picker

Doesn't matter.... the converter is connected directly to the battery too.
It's the same result.

Everything that is 12v is somehow connected to the battery and the converter simply supplies a supplement to the battery (when plugged into shore power) and to keep the battery charged.

The UltraHeat expert has a different opinion from you 5picker. He stated if the heat pads are directly connected to the batteries they will drain the batteries faster that the converter can charge the batteries. He said it is like using a water hose to fill a bucket (converter to batteries) and using a fire hose to put out the fire (batteries to heat pads). The batteries cannot keep up. The converter should directly connect to the heat pad when it is plugged into land line power. Of course, if you are not plugged in, then the batteries are on their own and will drain even quicker.

I'm wondering if others agree with the UltraHeat expert on this.

[azric]

Thanks for correcting my mixup on watts/amps. This makes me think the land line power may have been out sometime during the night so only battery power was being consumed. May be multiple factors going on here.

[5picker]

Originally Posted by azric

The UltraHeat expert has a different opinion from you 5picker. He stated if the heat pads are directly connected to the batteries they will drain the batteries faster that the converter can charge the batteries. He said it is like using a water hose to fill a bucket (converter to batteries) and using a fire hose to put out the fire (batteries to heat pads). The batteries cannot keep up. The converter should directly connect to the heat pad when it is plugged into land line power. Of course, if you are not plugged in, then the batteries are on their own and will drain even quicker.

I'm wondering if others agree with the UltraHeat expert on this.

I've never seen (from the factory) a converter wired/connected to a battery(ies) that wasn't wired with ample gauge wire to effectively put the full output of the converter into the battery. So, if your converter is wired with 18 ga wire (garden hose) instead of the heavy guage wire (fire hose) necessary, then his statement 'might' hold some credibility but certainly not if it is done the way most all factory converters are wired that I have seen.

[Cypressloser]

If the shore power went out overnight then your microwave must have been flashing in the morning.
The converter should have absolutely no problem supplying the amps needed to keep the batter(y)ies charged. Lets say your furnace motor burns 18 amps and your heat pads another 18 amps that only 2/3 of its capacity.
Another question, how old are your batteries, what type are they and how often have they gone belly up (died) since new?

[Scrapper]

azric, Look at it this way, the reason your stabilizers and slide outs are connected directly to the batteries is because the converter/charger cannot supply enough power to run them.

Your tank heaters are most likely a high current draw and the charger will have trouble supplying enough to operate the furnace fan, tank heaters and lights at the same time on top of keeping the battery charged.

If your lights are incandescent, change all of them to LED. With every LED light on, you will use less power than 1, maybe 2 incandescent bulbs.

[Cypressloser]

The incandescent light bulb scenario makes a lot of sense but most people turn the lights off when they go to bed and if not the batteries should have had enough reserve charge to make it easily through the night.

[camaraderie]

I think the OP needs to install a REAL battery monitor system ($150) from Victron or Trimetric so that he can SEE in real time:
State of Battery Charge
Amps IN vs. Amps out
Charging voltage & amps
When the battery is FULL.
When the battery is 50% Full and needs to be recharged to avoid damage.
How long you have left at this rate of usage.

I suspect run down batts at the root of the problem and inability to keep up with the loads as a result. Plus light wiring often limits amp delivery to batts. Suggest checking water levels and leaving them under charge for a day to see if they come up all the way when not under load.

[Jonol]

5picker is right!!

[bubbles]

Seems to that a converter should be able to operate all 12 volt items on board even with the battery disconnected.

[Flybob]

Not sure how much faith I would put in the Ultraheat rep. 5 picker is correct. Battery connected to converter with heavy enough gauge wire that it will make little to no difference. In most cases the converter is capable of supporting the 12VDC demands of an RV, however there are a few times when it can fall short and require help from the battery. One of these can be when extending large slides especially at end stall.

[tbarb]

In post #1 he states he was plugged into 30 amp shore power. If battery charger was on high charge, heater was running, heating pads were drawing power and refrigerator or hot water heater kicked on he was drawing more amps than would have been available.
Those that have more knowledge might chime in but when I am plugged into 30 amp shore power I am always concerned about overuse and I turn unnecessary items off.