Can someone answer my battery question??

[kholmes]

Hi all just left Canada on the 27th of Dec. Left minus 10 Celsius temperatures. Had unit plugged in for weeks to make sure batteries were fully charged. Drove for 10 hrs first day arrived in minus 6 degree temps in Montana and stayed in hotel. Rig not plugged in. Drove 12 hrs next day and nighted over in walmart parking lot. Furnaces started and worked great but in 2 to 3hrs batteries had dropped down from fully charged to 3rd charge and where dead by am. Froze are butts off. Is it normal for batteries to drop charge that quickly. I have 2 newer 12volt batteries. Ran furnace and no lights. Only draw that I think we had outside of furnace was co detector and fire alarm. Would it be normal to lose all battery capacity from 2 batteries in 7 to 8 hrs?? Thanks everyone one and Happy new year to all.

Randy

[babock]

How many hours are your furnaces on? On my small trailer, my one furnace draws around 7A. For me, if my furnace is on 50% of the time for 8 hours, that's 28AH. What other loads do you have besides your furnace? Residential fridge?

What does "3rd charge" mean?

[kholmes]

Originally Posted by babock

How many hours are your furnaces on? On my small trailer, my one furnace draws around 7A. For me, if my furnace is on 50% of the time for 8 hours, that's 28AH. What other loads do you have besides your furnace? Residential fridge?

had set at 70 degrees not sure what time it shut down. Nothing else running but it didnt make it through the night cause their was frost on my wife's pumpkin!!

[babock]

Originally Posted by kholmes

had set at 70 degrees not sure what time it shut down. Nothing else running but it didnt make it through the night cause their was frost on my wife's pumpkin!!

70 degrees and it was 14°F outside? I bet your furnaces were on 100% of the time. We set ours to 60 at the highest to preserve battery and that is with much warmer temps.

[Flybob]

If original batteries, they are at least 4 yrs old and running furnace at 70F all night can easily drain batteries below the shut off voltage for the furnace. Easy quick solution extra blankets and temp at 55F or 60F overnight.

[TitanMike]

Based on what I gathered from your post (OP's) your batteries may not have been fully charged once you unplugged the first time.

Merely driving for a normal days travel won't provide enough current to fully charge a battery that's powered a furnace for any length of time, along with the usual power consumption. If you don't stay in a campground and plug in, a generator is pretty much a necessity to recharge the batteries anywhere near full.

I like to start my generator in the morning when I first start moving (as long as I'm not in a restricted "generator hours" place and let the converter/charger put as much power in the batteries as possible. This higher current also warms the batteries so they will more readily accept a charge which is as much a chemical reaction as electrical. Heat speeds chemical reactions and the published "Ideal Temperature" for batteries is 77 degrees (electrolyte temp).

While the Generator is running I can brew coffee, use the microwave, toast bread, and all the other things one often does for breakfast. Once ready to hit the road again, turn off generator and NOW let the Tow Vehicle finish off the charge as you drive to your next stop.

As for where to set the thermostat, I started camping in tents so snuggling into a nice warm sleeping bag was how we did it. Now that I am in a trailer I set the furnace down to it's lowest setting (55 degrees on mine) and rely on the sleeping bag for warmth (along with my dog that burrows in with me). This setting will keep things from freezing and it doesn't take long to warm up in the AM. Before my wife passed away and she was still camping with me she'd wake me and tell me to start the furnace. Funny how marriage works

In closing, I don't know what your battery setup is but just adding more, larger batteries won't really help unless you have a way to make sure they are fully charged before the next eve's stop. Tow vehicle charging current (to trailer) drops rapidly after the engine is started with trailer connected. It's caused by the small wires between TV battery and Trailer Batteries. Large voltage drop makes the charging system think everything is fully charged and voltage is regulated downward.

That was pretty long so I'll call it my "three cents worth".

[Cypressloser]

The furnace fan is a power hog like no other.
If you have 2 smallish hybrid batteries especially in sub freezing weather and when the batteries are exposed to the cold 1 - 2 nights sounds about right.

[tomrob1161]

I would also assume that you retracted, extended your slideouts, that alone would have pulled a lot of juice from your batteries.

[TGR]

I have a single battery in my 5th wheel trailer that can’t make it through the night running the furnace. I would have thought that two batteries would have kept you warm all night but I’m not too surprised that they failed with the temperature going down -10 C.

I don’t have any issues with my truck charging my battery while traveling. It keeps fully charged and even gets its charge topped off between overnight stays when traveling for several hours between stops. Out of curiosity, I would check to ensure your tow vehicle is sending current to your battery while traveling just to be sure everything is working properly.

When camping in cold weather for several days, I use a generator to both keep the power going for the lights and furnace and to run a dehumidifier as I feel there is too much condensation in the trailer for its own good under these conditions.

[TitanMike]

Originally Posted by tomrob1161

I would also assume that you retracted, extended your slideouts, that alone would have pulled a lot of juice from your batteries.

Interestingly enough these aren't the big drain that kills batteries. I measured the current to extend/retract my slide and it was only around 10 amp as I recall. Current draw only lasted for a minute or less.

At that rate, for that amount of time, the power consumption was less than 1/4 amp hour.

My furnace fan only draws 5 amp max and the reason it consumes so much power (amp hours) is the fact that it can run for 4-5 hours in an evening in total, longer if really cold. If you have a sigle 100 ah battery it's easy to drain one overnight if one insists on using the "extra cozy" setting on the thermostat Now add in the lights, TV, Stereo, Water Pump, Fan, charging cell phones, etc and it's easy to see where battery "energy" goes so quickly.

[NMWildcat]

For your two batteries to last all night with the heater you definitely have to change your usage pattern.

We boondock frequently when temps are teens or below. You have to start the night with charged batteries and set the propane heater to just keep your water lines from freezing. We set our heater at 40-50 degrees and have wool blankets for warmth. We also have electric blankets to pre-warm the bed while the generator is still on.

In the morning it's my job to get up and start the generator and/or turn up the heater. We rarely run out of battery doing this.

You will get the hang of it.......

[clintbonnie73]

The most important thing to do first is to check the condition of your batteries.. the best way to this is to purchase a "Hydrometer" from AutoZone or Oreillys..(cheap).. and charge the batteries for a couple of days and then use the Hydrometer to check the specific gravity with the tester... easy task.. If they check not fully charged.. replace the batteries.. My choice is to use two 6 volt batteries wired in series..

[camaraderie]

A real battery monitor would show you your exact state of charge at all times so you wouldn't have to guess. It is unlikely that your batteries were fully charged after the first nite and it all goes downhill from there. Using your batts to well depleted and then not FULLY recharging them (on a converter for at LEAST 6 hours!) is the surest way to deplete capacity and eventually murder batteries.

[rsdata]

COLD batteries do not produce as much power as those around at 70F...

You do not mention what TYPE or SIZE of batteries...

12V we got but group 24? or 27? starting batteries? or true DEEP CYCLE? cheap or expensive? old or new?

Look into propane powered small heater... perfectly safe...

[normy41]

Chances are very good that you may have one or (even possibility of more than) bad cells in your batteries. Not sure how you store your trailer but I personally take my batteries out if my unit is stored for a number of weeks at any time. Yes it is a PIA to do this but it saves the batteries life. Even with what you might think are fully charged batteries, if you have a bad or dead cell in your batteries it will deplete your batteries quicklywhen in use? My advice would be to replace your batteries? Good luck!

[clintbonnie73]

Originally Posted by normy41

Chances are very good that you may have one or (even possibility of more than) bad cells in your batteries. Not sure how you store your trailer but I personally take my batteries out if my unit is stored for a number of weeks at any time. Yes it is a PIA to do this but it saves the batteries life. Even with what you might think are fully charged batteries, if you have a bad or dead cell in your batteries it will deplete your batteries quicklywhen in use? My advice would be to replace your batteries? Good luck!

A Hydrometer check will show a bad cell..

[litgrep]

Also, are you sure you're getting a charge from your tow vehicle. Many vehicles sold prepped for towing don't hook up the 12v charge to the trailer plug. Mine was even strapped to wiring harness to the fender box and no fuse in the box.

[kenrod1966]

Originally Posted by TitanMike

Interestingly enough these aren't the big drain that kills batteries. I measured the current to extend/retract my slide and it was only around 10 amp as I recall. Current draw only lasted for a minute or less.

At that rate, for that amount of time, the power consumption was less than 1/4 amp hour.

My furnace fan only draws 5 amp max and the reason it consumes so much power (amp hours) is the fact that it can run for 4-5 hours in an evening in total, longer if really cold. If you have a sigle 100 ah battery it's easy to drain one overnight if one insists on using the "extra cozy" setting on the thermostat Now add in the lights, TV, Stereo, Water Pump, Fan, charging cell phones, etc and it's easy to see where battery "energy" goes so quickly.

We have a Residential Refrigerator in our camper and we have three 100 amp batteries and we will drop to 50% if the Residential Refrigerator is turned on.

[2rad4u]

Originally Posted by babock

70 degrees and it was 14°F outside? I bet your furnaces were on 100% of the time. We set ours to 60 at the highest to preserve battery and that is with much warmer temps.

This ^^ That furnace was working... hard ...

[Brother Les]

This is what is called 'a learning moment'....