2014 FC - battery question

[dmbecke]

We are going on a week long trip in which we will be parking the entire week at a full hook up campground. However, we will be leaving the airstream for 2-3 days to visit family
Just more convenient to leave it and weekly rate was reasonable
So my question is .. how do I leave the fridge running and should we leave the air conditioner on at 80 degrees?
I haven't yet switched out converters, so will leaving like this plugged into shore power fry my two new group 31 batteries ? How do I leave trailer running without overcharging batteries?

[uncle_bob]

Hi

Do you have solar? If so, just let it handle the 12V stuff. If not and you want the fridge, let it run on shore power. If it's on shore power, run the AC as well. If you are on 12V solar, obviously the AC is out. Given the mind numbing number of ways that AS has wired disconnects (and the possibility of custom wiring in your trailer), there are a whole bunch of odd things you *might* be able to do.

Bob

[dmbecke]

Thanks Bob, no solar and I believe standard equipment for a 2014
Should I unplug from shore power and run fridge on propane and 12v?
I understand that doesn't use much power
What could I run off 12v that would keep the batteries from being over charged if I stayed plugged in?

[wulfraat]

Originally Posted by dmbecke

We are going on a week long trip in which we will be parking the entire week at a full hook up campground. However, we will be leaving the airstream for 2-3 days to visit family
Just more convenient to leave it and weekly rate was reasonable
So my question is .. how do I leave the fridge running and should we leave the air conditioner on at 80 degrees?
I haven't yet switched out converters, so will leaving like this plugged into shore power fry my two new group 31 batteries ? How do I leave trailer running without overcharging batteries?

Leave the trailer on shore power and switch the interior battery switch to "store" mode. 12v and 120v will continue to be supplied by the converter / shore power but the converter/charger will be disconnected from the batteries and hence will not over-charge them.

[OTRA15]

Leave it plugged into shore power for 2-3 days, in the Use mode, and your batteries will be fine IMO. Boiling the batteries takes much longer than 2-3 days.

To allay your concerns, the day before you leave the trailer absent, unplug from shore power and run the trailer entirely on 12-volt power if you can (if you don't need the A/C). Time this so that your battery voltage gets down to 12.5 or so (90% of capacity) just before you leave. Then plug back into shore power in Use mode, and leave for 2-3 days.

The batteries will be fine. We have been doing this for 2 years with our 2014 FC20 in the driveway and our batteries are in good shape. We just took a 4 day boondocking trip, and all is well.

Have a great trip!

Peter

PS -- The suggestions to put the batteries in Store mode [and thus not being charged by shore power] are also fine, but your batteries will lose some charge in your absence. In 2-3 days this loss should be acceptable if you don't need to leave for boondocking right after you get back. This is the safer alternative of course.

[dmbecke]

Originally Posted by wulfraat

Leave the trailer on shore power and switch the interior battery switch to "store" mode. 12v and 120v will continue to be supplied by the converter / shore power but the converter/charger will be disconnected from the batteries and hence will not over-charge them.

Thanks, this sounds perfect.
I don't understand this switch.
If 12v and shore power is still on when this is moved to store mode, then what does this shut down?

[lsbrodsky]

It essentially isolates the battery from everything except tow vehicle charging and solar charging. Your converter will supply DC to your DC loads if you are plugged in to shorepower. In the USE mode, the battery is back in the circuit.
Larry

[uncle_bob]

Originally Posted by dmbecke

Thanks, this sounds perfect.
I don't understand this switch.
If 12v and shore power is still on when this is moved to store mode, then what does this shut down?

Hi

As mentioned, it isolates the loads. The exact function of that switch changes every few years and in some cases is different depending on the model. They really don' t have a single coherent idea.

Bob

[ArkFortyCal]

For 2-3 days I would leave every thing as it is when you are there. Set A/C to 80+ and leave the frig and store switch alone.

[OTRA15]

Originally Posted by dmbecke

Thanks, this sounds perfect.
I don't understand this switch.
If 12v and shore power is still on when this is moved to store mode, then what does this shut down?

You should read your owner's manual on this, just to make sure what the exact function and location of your Use/Store switch are.

[cazual6]

Originally Posted by ArkFortyCal

For 2-3 days I would leave every thing as it is when you are there. Set A/C to 80+ and leave the frig and store switch alone.

i concur

[Glenn T]

Given the number of ways AS has wired 12v systems, I'd recommend just lifting the positive lead off of the battery bank while you're away.

The Parallax converter will still power the 12v system just the same, but you won't charge or drain the batteries. Just be sure that the positive cable doesn't ground to anything in the battery box.

When you get home, order and install a proper charger. Your batteries will last longer, and you won't have to worry about overcharging.

[jamieb1086]

And if you're leaving the rig, DO NOT forget to turn the water off (or put the hose away completely)at the campground spigot! Electrical problems are bad, water problems are worse!

[OTRA15]

Good one! Stow the hose.

Another misc. suggestion is to make sure the water pump is turned off, and to use a surge protector for your shore power connection.

[Al and Missy]

Originally Posted by Glenn T

Given the number of ways AS has wired 12v systems, I'd recommend just lifting the positive lead off of the battery bank while you're away.

The Parallax converter will still power the 12v system just the same, but you won't charge or drain the batteries. Just be sure that the positive cable doesn't ground to anything in the battery box.

When you get home, order and install a proper charger. Your batteries will last longer, and you won't have to worry about overcharging.

If disconnecting, the safer way is to disconnect the negative cables. You should disconnect every negative cable except the one that ties the two batteries together. If they touch trailer ground, no problem.

This is also the safest way to disconnect batteries for maintenance. Disconnect negative cables first, connect negative cables last.

Al

[CruizinDux]

This is a post (#5 by dkottum who always provides sound advice) from 2016 that I thought very interesting. http://www.airforums.com/forums/f449...on-148837.html

I have asked a few RV electricians but no one could verify.

[QUOTE=dkottum: Something I have recently realized is the constant single-stage charging voltage of the factory converter/charger can ruin your batteries over the long term if connected to shore power and the trailer electrical equipment is not in use, like at home in the driveway.

However, if you are camping, plugged into external power, and using the trailer electrical equipment, the factory converter/charger is not nearly as damaging to your batteries. This is because the batteries are in use and being discharged at the same time as being charged.

So its okay to have the battery switch in USE position on external power when the trailer is actually in use. But if simply parked at home between trips either put the battery switch in STORE if connected to external power, or do connect to external power except for short periods to keep the batteries up.]

Maybe the 12V refer draw + the LP detector...add the radio and a few lights would be sufficient a draw on the batteries.

Comments and clarification appreciated.

bob

[OTRA15]

Good evening Bob!

I thought that when the converter is connected to shore power, that it supplies all the 12-volt juice needed by the trailer? Thus that theory may not hold water?

One wild card here is that the Use/Store switch has not performed the same consistent functions in all models in all years IMO. This makes for some extra possible variables when one is reading older posts about these matters IMO.

When we store our 2014 FC20 in the driveway, we unplug from shore power 1-2 times per week, and use the batteries until they go down to 12.5 volts (about 90% capacity). Then we charge for 2-3 days, and constantly monitor the water level. In almost 2 years of this, the batteries have required probably a total of 1/4" to 1/2" of added distilled water total. Seems healthy to me.

Peter

PS -- Glad you got your AS back from the dealer, if I read that other post correctly?

[CruizinDux]

Originally Posted by OTRA15

Good evening Bob!

I thought that when the converter is connected to shore power, that it supplies all the 12-volt juice needed by the trailer? Thus that theory may not hold water? That's what I always thought...hence the ?

One wild card here is that the Use/Store switch has not performed the same consistent functions in all models in all years IMO. This makes for some extra possible variables when one is reading older posts about these matters IMO. Great point

When we store our 2014 FC20 in the driveway, we unplug from shore power 1-2 times per week, and use the batteries until they go down to 12.5 volts (about 90% capacity). Then we charge for 2-3 days, and constantly monitor the water level. In almost 2 years of this, the batteries have required probably a total of 1/4" to 1/2" of added distilled water total. Seems healthy to me.

Peter

PS -- Glad you got your AS back from the dealer, if I read that other post correctly?

....almost. They said 2 weeks for the sail/limit switch and we're a week into that.

If were using the TT within 2 weeks, I disc the neg as we have no SP at storage. Longer than that they have a spot on my bench with a smart charger. 3-4 days on....letr' drift for a few weeks. The cycle begins anew. Having them home also allows me to watch the H20. However I keep a catsup squeeze bottle of dist H20 in the aft storage by the light held secure buy a gal pipe strap to dose the batteries when I'm on the road.

Bob

Edit: when in a park with SP which is generally the case I often go to store if I'm there longer than 4 days or so. Downside is then I have to reprogram the stereo light show....darkness darkness, be my pillow....

[dmbecke]

Originally Posted by jamieb1086

And if you're leaving the rig, DO NOT forget to turn the water off (or put the hose away completely)at the campground spigot! Electrical problems are bad, water problems are worse!

Great idea, thanks

[OTRA15]

Originally Posted by lsbrodsky

It essentially isolates the battery from everything except tow vehicle charging and solar charging. Your converter will supply DC to your DC loads if you are plugged in to shorepower. In the USE mode, the battery is back in the circuit.
Larry

In this case, on shore power, with the switch in the Use mode, do the trailer's 12-volt functions actually draw energy from the battery, even though the converter is also on? That is what CruizinDux Bob in Post #16 was saying had been reported earlier by dkottum:

Originally Posted by CruizinDux

. . .
dkottum:
. . .
However, if you are camping, plugged into external power, and using the trailer electrical equipment, the factory converter/charger is not nearly as damaging to your batteries. This is because the batteries are in use and being discharged at the same time as being charged.
. . .

Therefore, Larry, is it correct in your opinion that the batteries are less likely to "cook" when:
shore power is on;
the battery switch is in Use mode; and
some 12-volt functions are functioning, like the thermostat to run the A/C, and the fridge's control board, as is the case here with the OP's situation?

Thanks,

Peter