Can a weak battery cause problems while on shore power?

[cc102bob]

I purchased a new Rockwood fifth wheel last summer and (insert long story about my stupidity here) I managed to drain the battery all the way down. After plugging the RV back in everything appeared to return to normal, but I know that completely draining a battery like that will cause some amount of permanent damage. Note that since that time, the RV has always been plugged into shore power unless being towed somewhere.

Fast forward to this year and we set up our camper on a seasonal site. Most things appear to be working OK, but the furnace doesn't want to work properly. It tries to fire up, but after the burner ignites and burns for a few seconds, it shuts back off again. It repeats this three times and then gives up completely. I'm wondering if it's possible that a weakened/damaged battery would keep the 12V system from getting full voltage even though the inverter is working properly?

I don't have a multimeter with me right now, but plan to bring one along next weekend. I'm hoping someone may have some ideas of something for me to look at before I try to get the dealer to do some warranty work (I'd rather not be without my RV for half the summer...).

There is a secondary bit of information: Our Rockwood came with a factory installed WiFi Ranger Sky 4 (wi-fi signal booster). I have been trying to use it this weekend, but has been kinda' flaky. I emailed tech support and they suggested verifying that the unit is getting the proper voltage. To me, that's another clue that my 12V system may not be quite right, but because I don't have a meter handy, it's hard for me to verify.

Thanks for any thoughts you may have!

[cboss]

Are you hooked to shore power at the site? If not it may be the battery.
If you are hooked to shore power the heater has a "sail switch" that makes sure the fan has enough RPM to safely use the heater. Sometimes these switches get stuck due to gunk, bugs, dust, etc. slowing the RPMs down.
Tons of posts about this, try a "search".

[Biggerfoot]

I'm wondering if your battery is shorted? Try unhooking it and turning the heater on. Most auto parts stores will load test the battery

[boondocking]

Turn on the stove to purge the propane lines. Once that is done then keep trying the furnace.

I had to do a reset on my water heater 8 times to get burner to stay operating. That was even after purging the lines via the stove.

[Skip12]

In my experience, yes, a weak battery can cause problems. Test with your multimeter. Be sure to disconnect the battery first. I've used jumper cables to the truck (again, with disconnected camper battery first) to see if thing work better with a different battery. Hope that helps.

[Brother Les]

A bad/low/shorted out battery can not and will not allow the furnace to fire up. The converter is just a trickle charger and does not have enough sustaining voltage to run the blowers and ignite the furnace, and your battery may not ever fully charge again if bad. Pull the battery and have it fully charged on a battery charger ( not camper 'convertor' ) and then have it 'load tested'. If battery has a bad cell or does not hold a good charge, replace it.


Also, you may just have air in the propane lines that need to be purged out and this may take a few tries.

[cc102bob]

Thanks everyone for the suggestions!

I have purged the propane lines. The feed to the furnace is before the stove and outside grill connections and I used both of those items just fine. I even went so far as to loosen the gas line connection on the furnace to verify that propane was getting that far (ooh! that smell!).

I'm really hoping to not have to take the furnace out to check sensors and what-not. It took me a half hour just to disassemble things far enough to reach the propane fitting. Getting things torn apart far enough to get the furnace out would require significantly more time. Seeing as how the furnace is less than a year old, I'd hate to think sensors are going bad already.

I was hoping to do more this weekend and was going to try and find someone in the park with a multi-meter I could borrow, but the weather forecast was horrible so the park cleared out. My wife and I stuck it out, but I'm not sure why. We sat through 30+ continuous hours of rain and wind. YUCK! I left at 5 PM today and it was still raining. My wife is sticking it out until tomorrow.

It will be easy enough to take out the battery and do some testing on that. Not that I want to spend money on a new battery, but if that fixes the problem I can just call it a "being stupid" penalty. It would sure beat having to remove the furnace!

[boondocking]

Hopefully it is just the battery.
Wish you good luck.

[cc102bob]

Oooh.. I have a "maybe related" question: Our trailer has 50 amp service and the lot we are on has 50 amp service, so things looked good upon arrival. However, when I plugged in my power cord and turned on the breaker, initially I could only get indicator to light up on the power cord (apparently the cord is built with LED indicators when power is detected on each leg). I ended up bending the prongs on the cord a bit until I got both LED indicators to light up. Would it be possible to have one leg of the 50 amp circuit be "weak" because of a "just barely" connection in the outlet? And would that possible cause issues feeding the inverter/12V system?

[jimmarako]

Originally Posted by Brother Les

A bad/low/shorted out battery can not and will not allow the furnace to fire up. The converter is just a trickle charger and does not have enough sustaining voltage to run the blowers and ignite the furnace, and your battery may not ever fully charge again if bad. .

Doesn't the typical WFCO converter the UltraLites comes with put out something like 55 Amps?
https://wfcoelectronics.com/product/wf-8955-55-amp/
Even if its not that high its way more than a trickle charger. I'm pretty certain I've read posts of people having no battery and being able to run their trailer.

A dead/weak battery may be the OP's problem. I don't know if it could swamp the converter trying to draw all 55 amps.

Jim M.

[Oaklevel]

One other thing when towing you need the battery to have charge. If the trailer ever breaks away from the tow vehicle you need the battery to operate the brakes stop the trailer.

[Brother Les]

Originally Posted by jimmarako

Doesn't the typical WFCO converter the UltraLites comes with put out something like 55 Amps?
https://wfcoelectronics.com/product/wf-8955-55-amp/
Even if its not that high its way more than a trickle charger. I'm pretty certain I've read posts of people having no battery and being able to run their trailer.

A dead/weak battery may be the OP's problem. I don't know if it could swamp the converter trying to draw all 55 amps.

Jim M.

The converter will run the 12v lights and most 12v systems without a battery, on the converters output alone. The more 12v demand, the dimmer the lights....The furnace must have a good battery to fire up. The converter output will rise higher when more lights are on and reduce when less 12v power is needed (if there is a good battery). The surge of needed power to start the furnance is not enough from just the converter and must have a battery for the initial power demand.

[TitanMike]

Originally Posted by Brother Les

The converter will run the 12v lights and most 12v systems without a battery, on the converters output alone. The more 12v demand, the dimmer the lights....The furnace must have a good battery to fire up. The converter output will rise higher when more lights are on and reduce when less 12v power is needed (if there is a good battery). The surge of needed power to start the furnance is not enough from just the converter and must have a battery for the initial power demand.

Lights alone don't draw much power at all. I can turn on all the lights in my TT, run the furnace, TV, DVD player, both exhaust fans, refrigerator (control board on propane refer) and not even use half the output of my converter. LED lights draw very little current.

If there 12v system problems while plugged in I wouldn't blame the battery.

If not plugged in and 22v issues, by all means it's a battery issue.

[BobHanke]

Low battery power may not be corrected just because you are on shore power. If possible, hook a battery charger to your batteries while trying the furnace. If that works, batteries are low and need to be replaced or deep cycled. RV Repair Club covered that last night.

[awellis3]

Replace the battery and solve all your problems. You killed it and now it's a zombie in your electrical system.

[Tom-n-Dale]

You might also have mud daubers in the air input and exhaust on the outside. If you don't have wire covers, this is a good place to look. They will prevent it from working.

[primo20]

I had charging issue from a simple loose battery connection. No furnace issue but we only camp in the summer in Canada. Lol. But charging issues on shore power nevertheless.

[SlowrideHD]

Originally Posted by TitanMike

Lights alone don't draw much power at all. I can turn on all the lights in my TT, run the furnace, TV, DVD player, both exhaust fans, refrigerator (control board on propane refer) and not even use half the output of my converter. LED lights draw very little current.

Absolutely true! Most converters will output plenty of amps to run all your 12 volt functions.
This is a method I have used to see just what the converter is using (120 v input) to run my 12 volt applications.
1. Get a Kill-a-Watt meter (Amazon, P3 P4400 Kill A Watt Electricity Usage Monitor)
2. Plug the meter into a good 20 amp receptacle and use whatever dogbones or adaptors you have to power up your rv and plug into the meter.
3. Do not use any 120 volt appliances in your camper (water heater, a/c, microwave, etc) while testing.
4. Turn on every 12 volt light you have and check the meter. It will tell you just how many amps and watts your converter is using from the 120 volt source to power your lights.
5. Do this same thing every time you turn on additional 12 volt appliances or functions. Some things require help to watch the meter such as when you operate slides or hydraulic pumps.
6. Following this method will show you just what can be run from your converter and/or battery. You can disconnect your battery bank to see what your converter only is capable of.
7. The Killowatt meter is fairly cheap and a great addition to monitor any single 120 volt outlet output.

[Biggerfoot]

Originally Posted by SlowrideHD

Absolutely true! Most converters will output plenty of amps to run all your 12 volt functions.
This is a method I have used to see just what the converter is using (120 v input) to run my 12 volt applications.
1. Get a Kill-a-Watt meter (Amazon, P3 P4400 Kill A Watt Electricity Usage Monitor)
2. Plug the meter into a good 20 amp receptacle and use whatever dogbones or adaptors you have to power up your rv and plug into the meter.
3. Do not use any 120 volt appliances in your camper (water heater, a/c, microwave, etc) while testing.
4. Turn on every 12 volt light you have and check the meter. It will tell you just how many amps and watts your converter is using from the 120 volt source to power your lights.
5. Do this same thing every time you turn on additional 12 volt appliances or functions. Some things require help to watch the meter such as when you operate slides or hydraulic pumps.
6. Following this method will show you just what can be run from your converter and/or battery. You can disconnect your battery bank to see what your converter only is capable of.
7. The Killowatt meter is fairly cheap and a great addition to monitor any single 120 volt outlet output.

Wouldn't a volt meter do the same thing or does the kill a watt also display amps?

[Larry-NC]

Originally Posted by jimmarako

Doesn't the typical WFCO converter the UltraLites comes with put out something like 55 Amps?
https://wfcoelectronics.com/product/wf-8955-55-amp/
Even if its not that high its way more than a trickle charger. I'm pretty certain I've read posts of people having no battery and being able to run their trailer.

A dead/weak battery may be the OP's problem. I don't know if it could swamp the converter trying to draw all 55 amps.

Jim M.

Jim, I agree with you--the converter is more than a trickle charger.

A dead/weak battery might not show the OP's symptoms, but a battery with a shorted cell certainly could. Nominal voltage for a "flooded lead acid" battery is 2.1 volts per cell, or 12.6 v. for the battery. If one cell shorted, fully-charged voltage drops to 10.5 v. That, indeed, could be low enough to cause problems with the furnace.

1. The OP could certainly pull one lead from the battery and run directly from the converter to see if things are better.

2. A shorted cell is easily detected at the auto parts store.