House batteries draining: a MYSTERY!!!

[johnschnee]

Our 2014 Bounder 35K's house batteries (OEM, 2 12 volt batteries) have recently been draining down significantly over just a few days, even when the "battery disconnect" switches are engaged! I nosed around a bit & was surprised to find that, even when I've got the "battery disconnect" switches engaged, the inside televisions were still drawing power, as signified by the small red "power" lights lit below the screen.  I've started to unplug the TVs, but I'm STILL seeing a severe drain on the batteries!  I have been careful to top off both batteries with distilled water each month as part of my regular "preventive maintenance" & I did recently notice quite a bit of corrosion on the metal attachments holing the batteries fast. After just 5-7 days in storage I haven't even got enough "juice" in the house batteries to start the generator, so I have to run the engine for 15-20 minutes to allow the generator to start so's I can get the batteries charged back up.

I'm at a loss as to what's happening here to cause this: wondering if the batteries are just plumb "wore out" & need replacement, but after just 4 years of "1/2 -time use" that shouldn't be necessary? If anyone has any suggestion I'd be greatly appreciative! Thanks in advance!

[Chad Heiser]

If your televisions are still on and you are not plugged into shore power, then you have an inverter in your system.  The inverter is drawing power from the batteries and inverting it to 120v AC power to power the TV's (assuming the TV's are not 12 volt models).  If this is the case, that would be a significant draw on your batteries over time and is what is causinjg the issue.  The 12 volt kill switch will not kill high draw 12 volt loads like inverters or slide motors or leveling jacks typically.  Typically the 12 volt kill switch only kills power to the 12 volt distribution panel in the RV.  The high draw 12 volt items like an inverter are wired directly to the batteries and don't go through the kill switch or the 12 volt distribution panel.  If all this is the case, find your inverter and turn it off.  It should solve your problem.  Also, if you drew down your batteries significantly like you describe too many times, you could have significantly shortened their life and they could be suspect as well.

[Kirk W]

6 hours ago, johnschnee said:

After just 5-7 days in storage I haven't even got enough "juice" in the house batteries to start the generator, so I have to run the engine for 15-20 minutes to allow the generator to start so's I can get the batteries charged back up.

If your two batteries are fully charged again after only 15-20 minutes they are in very poor condition as it should take several hours when they are down. Have you taken any specific gravity readings or at least a voltage reading with a good volt/ohm meter? If so, you can check the level against this charge level chart. As a simple test of the batteries, make sure that they are fully charged and once they are, remove the cables from the negative post of each battery, letting them sit this way for at least 24 hours and check the voltage again. You need to isolate the two as one battery bad will drain down the other that may yet be good. If they are suspect, take them to a battery shop and have them load tested. 

[johnschnee]

Chad & Kirk: Thank you very much for your informative & helpful responses above! I will take a peek around for the 
"off switch" for my Bounder's inverter & I've made an appointment to have the batteries checked out next week.

THANKS AGAIN!