Batterys go dead

[handyman]

I thought I had this problem solved but it reard it's ugly head  again my batterys charge up and work fine when I'm pluged in to shore power and when I unplug the batterys switch over fine but then a few hours later with nothing on all the batterys go dead put a metter on     them and no drain It's like someone turns off a switch, when I plug back into shore power the batterys work again and show a full charge what gives with this thing

[Richard Peterson]

Just because you are plugged into shore power (120ac) does not mean your batteries are charging. The actual charge under this condition is very little.  What you are seeing is the converter supplying 12 volts and not the batteries.  You need to charge your batteries with a charger before using them.  I had the same problem until my friendly RV serviceman explained why I could not get a real charge while being hooked up to shore power.