Battery not charging

[TallPaul]

House battery was 11.98 volts.
Plugged in 24 hours, charging at 13.8 volts.
Half hour after unplugged, read 12.78 volts
21 hours later, read 12.62 volts.
7 days later, read 11.75 volts.

So it dropped nearly a volt sitting a week unplugged. Does that suggest a weak battery?

[RV Wizard]

Are you able to put an amp meter off the battery to determine if you have a current draw pulling the battery down? If not you would disconnect the negative post of battery (after charging) and redo your test to see if it holds better voltages for a longer period.

[TallPaul]

Should be no current draw as fridge and LP detector fuses are pulled. Still, I like your idea. Will try it. Thanks