Should I leave my battery plugged into shore power in cold

[gabriela]

Dear RVers:

My 30' Class C 2007 FR Sun Seeker is parked outdoors on my lot in Poconos PA, where lately we're averaging 5 degrees during the day. I had it professionally winterized in October, and that RV tech told me "do not leave your house battery just plugged in, it will dry up your battery." So I obeyed that, and come every week and plug it in to the house 110-volt outside plug and leave it that way 24-48 hours, and that gets the house battery charged up. I also start the truck engine, which I've read is NOT getting cross-charged just by plugging in the house battery to the outdoor shore 110-volt shore power.

I am noticing that my house battery is going down to 30% every 4 days or so (unplugged) in the cold, and being as we're in the coldest part of winter, with average this week and next in 5 degree range, I am very tempted to plug the RV into my 110 volt outside electrical outlet and leave for warmer climes for at next 2 weeks or so. I will leave the RV volt systems turned "on," as I've been instructed, otherwise the charging process is futile (I've been told). I understand that this will charge up my house battery, but not the truck battery. All fine.

What I am worried about is that I'll "fry" dry my house battery by doing this for two weeks. Any ideas, folk? Is this likely in 5 degree average temps? If it's true, that means I have to go back and forth, back to Poconos, coming from NYC, plugging and unplugging, which I am finding unpleasant and is like babysitting hens in a hen house.

Thanks for any advice. I want to plug it in and leave it for 2 weeks.

Sincerely, Gabriela

[Bobbo]

BurbMan wrote:

ksg5000 wrote:
Old fashioned converters which put out a constant voltage tend to boil off battery water and if you don't refill them regularly they will destroy your battery.

OP's rig is a 2007, for sure she has a 3-stage charger, most likely a WFCO 8955.

My Winnebago is a 2007 and came with a MagnaJunk 7345 converter. After about 3 years, I junked it and put in a PD4655.

Don't assume a good converter just because of recent manufacture or name brand.

[j-d]

Welcome to Class C! I went back to "View Posts" and it seems you did a lot of shopping and settled on this Sunseeker... Decent choice... the FR Class C line is really gaining popularity here.

If you had the coach winterized and parked it with fresh engine and generator oil and stabilized gasoline (and ran the generator to get that fuel into it!) then...

1. I don't understand why you haven't just taken both batteries inside for storage and occasional trickle charge.

2. Running the road engine without driving (or generator without a heavy load like a couple electric space heaters) doesn't benefit anything.

3. Unless your converter/charger is just off the chain voltage-wise it won't boil your batteries in that cold weather.

4. If you choose to leave the coach plugged in, get a little trickle charger and connect to your chassis battery. Or two of 'em and put one to each battery after you disconnect their negative terminals from the house and chassis.

I'm suspecting you may just not want to be lugging two or three heavy batteries from RV/storage to the house and back...

[tenbear]

You can always take your batteries, full with distilled water and fully charged, into your house. Just make sure you know how to connect them when you take them back out to the MH. A photo of the wiring would be a good idea.

[pnichols]

You need to keep in mind that any given voltage applied to lead acid battery terminals has less of an affect in charging them or maintaining them or boiling their water away as the temperature gets colder.

This means that the good old 13.6 to 12.8 volts from a single stage converter, left on batteries continuously during cold weather, will not have the detrimental effect that it could have during warm weather.

During hot weather I disconnect my 13.8V converter from the house batteries while the RV is in storage. During the winter in storage, I leave the fixed voltage converter hooked up to the RV batteries 24/7.

My batteries are over 8 years old and still going strong using this approach. They're AGM batteries so any water boiled away cannot be replaced ... so damage is irreversible.

[Yaj]

How about using a timer on the outlet. Set it to turn on a couple of hours every day.

[RoyB]

My 2008 trailer came with a ELIXIR Mdl ELX-30 SIngle Mode converter which I replaced WFCO 8900 Power Distribution Center with a WF8945 Smart Mode Converter and it never read anything except 13.6VDC everytime I measured it at the batteries. I eventually changed Just the CONVERTER UNIT out for PD9260C Converter/charger unit. This unit goes into the smart charging modes just fine.

I leave my trailers plugged into 120VAC from the Garage 20AMP receptacle using an adapter all the time here with no battery issues. I do check the battery on a regular basis for setting charge status and also check the battery fluids.

If i didn't have smart mode charging available I would disconnect the battery when parked. If the batteries have a good charge on them they will not freeze up during the cold weather periods. If they drain down to ZERO charge state they will freeze up inside and bust the battery walls...

Same thing will happen to your truck start battery. I would check it for charge status as well and never let it get below 50% charge state while sitting.

Roy Ken

[BurbMan]

ksg5000 wrote:
Old fashioned converters which put out a constant voltage tend to boil off battery water and if you don't refill them regularly they will destroy your battery.

OP's rig is a 2007, for sure she has a 3-stage charger, most likely a WFCO 8955.

[2oldman]

Stay plugged in in storage?
Stay plugged in roast batteries?
disconnect? Oct 2013
Stay plugged in Mar 2014
Stay plugged in Jun 2014
Stay plugged in Sep 2014

[pianotuna]

Hi Gabriela,

Welcome to the forums.

What you are seeing is not normal. I suspect the "house" battery maybe on its last legs.

Do you know the make of the converter?

If you wish to maintain the chassis battery when plugged into shore power have a Trik-L-Start added.

[ksg5000]

Old fashioned converters which put out a constant voltage tend to boil off battery water and if you don't refill them regularly they will destroy your battery. If you have one of these types of converters then unplugging is probably wise or make sure you monitor water levels frequently. Newer multi stage converters don't deplete water (at least not very much) and they are safe to leave plugged in.

If you decide not to keep the converter on you might consider disconnecting the negative battery cable - that will keep things like alarms etc from depleting the battery - a fully charged battery will do fine in cold weather.

[Dakota98]

Are the house batteries Lead Acid or AGM ?

First thing to determine is the make & model of your convertor & what type of charging system it has. If it a 3-4 stage charger, you'll be fine.

If your batts are Lead Acid, check the water levels FIRST.

[BurbMan]

I leave mine plugged in all winter. As long as your converter is working properly, it steps down the voltage to a trickle charge so it won't boil the batteries dry, but keeps enough current flowing so the batteries won't freeze.

I would leave it plugged in and check the batteries once a month, add water as needed.