Gard -  The only time our big LQ trailer is not plugged into a 110 outlet is when it is going down the road.  It is plugged into a 30 amp plug at the barn while it sits there, and the air or the heat is running when necessary.  Yesterday when ducking between the trailer and the back of the truck, I heard a sizzling noise coming from the battery box on the exterior of the jack wall.  The exterior of the battery box was very hot to the touch.  When opened, I found one battery that was also very hot, and disconnected both batteries and removed them.  I haven't yet taken them down to my shop so the guys could look at them.

Could it have been overcharged by the converter?  Is it not a good idea to keep a trailer plugged into 110?  We have been doing this for many years.  It really scared me, as it was hot enough to cause a fire given enough time, and the trailer sits next to the barn.

I feel really stupid about this, and if what we have been doing is not advisable, I need to tell my customers and clients about it.  We do not do any interior work on LQs, but sub it out to a mobile outfit.  I haven't called them yet.

Great topic I will jump in.  I will stay brief and to the point derived from experience.

If you are not installing a converter with charge control module you will boil your batteries dry.  Not all converters have this feature although more and more do.

I added the Charge wizard and have never have had a water issue in my batteries again.  I leave my batteries connected to shore power 24x7 when docked at home.  I do not run any appliances while in the yard.  I do remove all but the electric jack battery in deep winter and store indoors.

Below are a few links that explain the process fairly well including a chart for recharging time.

http://www.progressivedyn.com/prod_details/charge_wizard.html

http://www.marxrv.com/12volt/12volt.htm

http://www.marxrv.com/12volt/12volta.htm

Yes. It would open the circuit to the batteries, which would eliminate any charging from the converter.

Some of the newer power centers with converters have graduated charging systems that will not over charge a battery. They are very efficient and will properly maintain batteries while being stored or used hard. Some of the older converters will not taper off enough when the battery is charged, and will overcharge an unused battery. This will cause overheating, boiling water, damaged plates and ruin the battery.

It is less expensive to add a good battery maintenance charging system and turn off the master battery switch, than it is to swap out a power center with a better converter/charger. You can permanately install it or have a temporary cord supply, that you unhook when you want to use the trailer.

Hope you are doing well. BOL

I agree with Gard. Those buggers are expensive.   

I was lucky enough to be able to purchase the add on Charge Wizzard for my brand.  Check your model and research its capabilities for charge control. And hopefully any inexpensive add-ons.

If your capable and into learning a bit for yourself.  Pop off the covers of those batteries you removed gently with a flat screw driver end.  Use a flashlight and look inside.  Is the fluid covering the gray plates?  If not Purchase a gal of distilled water (purple cap) from Walmart (In the water isle) add water from that gal to just cover the plates.  You may save the batteries and save yourself a few hundred dollars in battery costs.

Next find in your LQ the electrical area.  Your converter is the box with a fan on it and may be attached so it is venting into the living space.  (these things need to cool themselves)  Write down the brand and model number.  You can post it here (we can help too) and also locate it on the internet.  Hopefully determining what options you have to upgrade economically if any.

There are several sources and brands of battery maintenance devices, if your power center can't be upgraded. Here's one

http://batterytender.com/

Kay, with your business, you can probably get these types of devices wholesale, and sell them to your customers, who may have similar difficulties. They work well over our winters when the trailers may sit dormant for several months.

The best part of this forum is the varied amount of info that is available. We are all fortunate to have this readily accessible. Thank you for your many contributions; we have enjoyed your valuable infomation from an expert, that is both unbiased and correct.

I store some cars, a boat, two trailers, and a tractor with batteries every winter. I can't recharge them all every month as I should, and replacing frozen batteries would get expensive.

A couple of years ago I bought a couple of these inexpensive float chargers. They worked well and I bought more. They will not charge a dead battery, and are only used when installed on freshly charged batteries. They're perfect for stored vehicles.

http://www.harborfreight.com/automatic-battery-float-charger-42292.html