to plug or unplug?

[trapper]

Hello fellow travellers, Could use some guidance. I am leaving my 2004 17 ft Little foot alone for two months while I play elsewhere. Batteries are topped up. Would it be best to remove and store, or plug the baby into shore..... oops house power while gone and let the onboard charger take care of the batteries. I believe when plugged in the battery charger cycles to keep the batteries up...right? Thanks for any and all guidance. Cheers, trapper

[Glenn Baglo]

If fully charged, I'd just disconnect the battery.

For more, Google Trojan battery maintenance.

[Dan Meyer]

I leave my camper plugged in when not in use, just to be certain the battery stays fully charged and doesn't freeze while being stored during a cold Minnesota winter.

--Dan Meyer

[Glenn Baglo]

From Trojan FAQ:
9. Can a flooded battery freeze?
The only way that a battery can freeze is if it is left in a state of partial or complete discharge. As the state of charge in a battery decreases, the electrolyte becomes more like water and the freezing temperature increases. The freezing temperature of the electrolyte in a fully charged battery is -92º F (-69º C). At a 40% state of charge, electrolyte will freeze if the temperature reaches approximately 16º F (-9º C).

[David B.]

If you have a propane detector, it might run the battery down enough in the two months left unpluged. I would just disconnect the negative or positive leads from the fully charged battery and enjoy your time away.
Dave & Paula

[gordon2]

Originally Posted by David B.

... I would just disconnect the negative or positive leads ...

Negative preferred, and SOP is to disconnect negative before positive.

Whether to leave the camper on shore power depends on what loads there are, and what kind of charger / converter you have. If you disconnect the battery then topping it off every 2-6 months is sufficient (and likely more than sufficient). As was mentioned, if you leave a propane alarm or other similar things operating then more frequent charging is called for.. likely weekly or so. If you have a quality charger / converter that is designed to be left on 24/7 then thats fine, but if it is a single stage cheepo, then leaving it on 24/7 can damage the battery.

[Darral T.]

I had a Corolla sitting in a garage with a new battery. About a year later, I noticed the battery starting to get 'weak'. I spoke with Batteries Plus and the lady asked...."Do you drive this car regularly?" I told her I did not...maybe once a month to just keep it from sitting. They replaced it then......

She gave me a battery lesson. I went to a Battery Tender (link below) and installed one on the Corolla, my Scamp, and motorcycle. That's been probably 3-4 yrs now and I've never had another battery problem and they're always "hot" when I need them.

These "Smart" chargers KEEPS the battery "topped off" - where they NEED to be and MUST be in order for them to last. Some of the Progressive Dynamic converters on Scamps (and others) comes with the "Wizard" which would do this for you so you could leave your RV plugged in continuously. If you do not have this Wizard, then do NOT leave your RV plugged as it will boil your battery dry if you're not vigilant and keep an eye on it.

I dont work for BT nor am I sponsored. I just use them and know they work. I bought 3 of the small 2A versions (Battery Tender JR) for a discount through Amazon several years ago. The warranty was/is 5 yrs on this model. That tells you something about their product. There's the BT + that is 10 YRS!

Battery Tender is the Most Trusted and Reliable Brand Since 1965. We Design, Manufacture, and Distribute Technologically Advanced Products that Meet the Ever Changing Needs of our Worldwide Customers. | Deltran Battery Tender

[Wayne Collins]

A fully charged lead acid battery will not discharge as long as it is disconnected, and clean and dry on top. Nor will it freeze.

[bobblangley]

Thanks to everyone for so many well-thought-out and helpful replies.

Here's another wrinkle -- I have an older trailer so it most likely does not have a very up to date charger/converter. It would seem that using something like a Battery Tender or Noco Genius would be the best choice. But, I store my trailer in an environment that is often humid and often cold so being plugged into shore power is almost essential as I operate a 110-v heater and dehumidifier fairly often.

I suppose that one option would be to upgrade the charger/converter. Can anyone recommend a great charger/converter for installation in a 1994 Bigfoot 17 that currently has a single 12-v battery and will likely have a solar panel installed at some point?

If I don't do that, would it make sense to hook up to shore power and disconnect the battery while the trailer is stored?

[gordon2]

Originally Posted by Wayne Collins

A fully charged lead acid battery will not discharge as long as it is disconnected, and clean and dry on top. ...

Bull Hockey


1. What is the shelf life of my battery?

Partial quote:

The limiting factor of battery’s shelf life is the rate of self-discharge which itself is temperature dependent. ... Flooded batteries will self-discharge up to 15% per month at 77º F (25º C). ... The specific gravity or voltage of flooded batteries should be monitored every 4 – 6 weeks and should be given a boost charge when they are at 70% stat of charge (SOC). ...

[Raspy]

Either disconnect the battery cables or leave the battery on a smart charger.

If there is any chance that you have a small load, such as a CO detector, or a light, or anything, leave it on a charger. But only on a smart charger. If your internal charger is not one that has a float function, get a modern tender that does and use that. If your on-board charger is a smart charger, you are all set.

If it is fully charged, you can disconnect the cables and it will be fine, if it is a good battery and stored out of the weather. No need to worry about freezing a fully charged battery. But it may self-discherge gradually over the period you leave it and that will lead to sulfation.

The best and safest way is to store it is to clip on a smart battery tender and leave the trailer unplugged. Or use the on-board smart charger and leave it plugged in. Make sure the battery does not need water. This will make sure it stays charged, doesn't freeze and minimizes any sulfation. If you do that you'll leave the battery cables connected. Then everything is ready to go.

[Raspy]

Robert,

Just noticed that you have an older charging system in the trailer. Get a smart battery tender and clip it on. Either leave the trailer unplugged or disconnect the battery so that your on-board charger is out of the loop.

[Darral T.]

Thanks Gordon2 for posting that. I knew it wasnt true...

Originally Posted by gordon2

Bull Hockey


1. What is the shelf life of my battery?

Partial quote:

The limiting factor of battery’s shelf life is the rate of self-discharge which itself is temperature dependent. ... Flooded batteries will self-discharge up to 15% per month at 77º F (25º C). ... The specific gravity or voltage of flooded batteries should be monitored every 4 – 6 weeks and should be given a boost charge when they are at 70% stat of charge (SOC). ...

[Byron Kinnaman]

Originally Posted by gordon2

Negative preferred, and SOP is to disconnect negative before positive.

That's a carry over from early automobile time. Doesn't apply to fiberglass trailers.
Reason for the disconnect negative first if you should hit a metal part of the automobile chassis with a wrench connected to positive terminal the wrench would get welded to the frame and batter terminal clamp,
Since is no metal chassis there no chance of the above happening.



Therefore it doesn't matter which terminal you disconnect or the order of disconnection.

[trapper]

Thank you all for your informative responses! I will check my Bigfoot handbook. Should have done that first....ooops. I believe the 2004 17 ft Bigfoot may have a built in smart charger when plugged into shore power. If not will fully charge and disconnect. Thanks trapper,

[burrorojo]

Hi Brian. I'm not sure what part of the province you live in but even here on Vancouver Island it gets chilly (below freezing in the Winter) though I'm fully winterized I have a low wattage heater in the middle of my unit. Not warm enuff to live in but it keeps the dampness down. The trailer is hooked to a proper outdoor timer. In the off season it goes on for one hour every day - so I never have a battery problem. In this season it's on (and heater) for 6 hours every night. Don't try using an indoor timer buy a proper amperage outdoor timer.

[gordon2]

Originally Posted by Byron Kinnaman

That's a carry over from early automobile time. Doesn't apply to fiberglass trailers.
Reason for the disconnect negative first if you should hit a metal part of the automobile chassis with a wrench connected to positive terminal the wrench would get welded to the frame and batter terminal clamp,
Since is no metal chassis there no chance of the above happening.



Therefore it doesn't matter which terminal you disconnect or the order of disconnection.

The frame on my Scamp is the same as the metal part of the auto.. the frame is metal and IS at negative potential (i.e. grounded). The frame makes electrical contact with propane tank hold-downs that are bolted to the frame cross supports, and the tank itself. Its all metal. A wrench on the positive battery post making contact with the tank hold-downs could make for a very bad day. And its always good to form good habits, so whether its a MFGRV or a auto, therefore I remove the neg first.



For the record, this is not my Scamp, but mine has about the same layout with the battery and tank.

[Spongelander]

Originally Posted by gordon2

The frame on my Scamp is the same as the metal part of the auto.. the frame is metal and IS at negative potential (i.e. grounded). The frame makes electrical contact with propane tank hold-downs that are bolted to the frame cross supports, and the tank itself. Its all metal. A wrench on the positive battery post making contact with the tank hold-downs could make for a very bad day. And its always good to form good habits, so whether its a MFGRV or a auto, therefore I remove the neg first.

While we're here... any time you're charging a battery, cut the power to the charger first, then remove the battery terminals.
Our high school auto shop floor had some serious etched concrete from a battery that exploded when a student walked up and simply unclipped it. Fortunately the side of the battery that went was away from him, or he'd have been covered in sulphuric acid.

[Mike_L]

The best way to maintain a battery is always with a smart charger which will keep it fully charged thus minimizing the potential for sulphation without over charging it which is also damaging. Leaving it connected to your trailer now becomes optional as your smart charger will compensate for the loads of your CO and propane detectors.
A conventional charger will also compensate for detector loads but may over time overcharge your battery.
A detached battery will self discharge over time with some sulphation occurring which will shorten battery life.

[WizWid]

Originally Posted by gordon2

The frame on my Scamp is the same as the metal part of the auto.. the frame is metal and IS at negative potential (i.e. grounded). The frame makes electrical contact with propane tank hold-downs that are bolted to the frame cross supports, and the tank itself. Its all metal. A wrench on the positive battery post making contact with the tank hold-downs could make for a very bad day. And its always good to form good habits, so whether its a MFGRV or a auto, therefore I remove the neg first.

Same on my Bigfoot - but with twice the batteries and twice the propane.