House Batteries Losing Charge

[Murphcrud]

Hello Guys,
How quickly will House Batteries lose charge?
Purchased 2 new deep charge 6V house batteries in March/18.  Full charged 12.7 V.  Used sparingly.  Parked MH after recent trip, again fully charged when parked reading 12.7V.  MH then sat for about 12-14 days without shore power.  Upon returning to storage area, the power steps would not engage.  Checked gauge control and noticed no battery power display and only displayed LP, other lights on gauge bank were either low (empty).  CO2 Light also was not on.  Batteries Dead.
My question is this - Is this a normal drain?  Should I be running my genny once a week to maintain battery?  Should I consider a small solar panel?
I am not near a electrical source.

 

[Optimistic Paranoid]

There's something wrong with your numbers.  A fully-charged 12 volt battery - or two 6 volt batteries wired together, same thing - will read 12.6 or 12.7 volts.  13.4 volts is a CHARGING voltage.  If you are reading THAT, then a converter or some other charging source is powering your system.  So your battery may, in fact, NOT be fully charged when you think it is.

 

[Murphcrud]

Your are correct.  I have modified the original post.  If you noticed the time when I originally made the post, I was still asleep and was going through my notes  :-[.  I did have the 13.4V number in my head, but upon revieving. that number was incorrect.  Thanks for correcting my information.

 

[WinterAdverse]

I also had a problem with the batteries dying while stored. I finally went all around the motorhome looking for things that were using electricity. I discovered that the 3 tv's in the motorhome, the stereo radio in the bedroom, the Dish receiver, & the DVR were always drawing power, even when turned off. My solution was to unplug all of it and to disconnect the radio, which was hard wired for some reason. We only use 1 tv anyway and never use the radio. Also it looked like the refrigerator for the external kitchen was also drawing power so I unplugged that too. I haven't had a problem since. Just FYI.

 

[Alfa38User]

How to insure EVERYTHING is off when stored?? Simply disconnect the ground lead (-) at the battery post!!! Either that or install a battery switch in that lead nearby the batteries. Note that in motor homes, and some trailers, the storage/use switch provided often does NOT shut everything off e.g. the propane detector alarm.

 

[Gary RV_Wizard]

First of all, Yes, it is not unusual for a modern motorhome to run the house batteries dead over a few weeks time. There are many things drawing a tiny current and it adds up to a significant draw. 


You didn't mention a make, yer or model of coach, so its hard to be very specific about , but most have a Battery Disconnect (aka Use/Store) switch that will remove most 12v power from the rig and help preserve battery life.  Use it and see how much it helps. Some things remain powered for safety reasons, but you can add the ground disconnect that Stu mentioned if necessary.


A battery can show OK voltage (12.6 indicates a full charge) and still have little amp-hours capacity.  Even though your batteries are almost new, it's conceivable the electrolyte in the cells is low, reducing capacity. Get in the habit of checking the level (remove the cell caps and peek inside) monthly until you have an idea about how long it takes to deplete the liquid. Add distilled water as needed. Learn more about checking/adding water at https://www.wikihow.com/Check-Car-Battery-Water-Levels


If your coach has an inverter, make sure it is turned off while in storage.  An inverter draws power even while in standby mode (nothing connected to it running), so turn it Off.


A moderate size solar panel can help if you have good sunlight. Don't bother with  those 10-12 watt plug-ins - they aren't worth the effort. An 18-25 watt panel will do some good.

Running the genset periodically is advisbale to keep it healthy, plus it enables the house system to get charged at the same time.  Run the genset monthy for 30-60 minutes. More often if your batteries aren't lasting.