Multiple Electrical Failures

[Jay Man]

Hi All! New to the forum and new to RV'ing, thanks in advance for your time. Last June we purchased a 2007 Keystone Hornet model M-37 FKDS that is parked at a year round campground. Yesterday was my first de-winterization and I ran into multiple electircal problems. Shore power was connected all winter and the deep cycle battery was left in place too. When I opened her up, the following don't work:
the slides wont move
the fridge won't power up
interior lights dont work
heat/ac/fan wont come on
water heater wont come on electric (didn't try gas)
Stereo wont come on
range hood light and fan wont come on

The following did work:
TV
Microwave
GFI outlets

No fuzes blown or breakers tripped. I didn't have a meter with me so couldn't do much with the battery. I pulled the battery, took it home, and put it on a charger so will see if that does the trick next weekend. My concern is that it seems the battery should've stayed charged and even if it has a bad cell it seems like the shore power should operate the lights, water heater, etc. Basically everthing except maybe the slides. I'm worried that I might have a bad converter. Thoughts?

[Festus2]

I am wondering if, over the winter when your converter was charging the battery, the battery eventually dried up which it would have if you didn't add water or check the fluid level in the cells. You may have "fried" the battery.
The slides require a fully-charged 12 volt battery to function and regardless of being plugged into shore power, will not operate unless the battery is good. The slides just use the 12v from the battery.
I'd continue to check the condition of your battery.

[Jay Man]

Thanks Festus, the battery is almost certainly the culprit. I'll have a look at the fluid levels tonight. I was just a little surprised the overhead lights and a/c wouldn't fire up. I don't have an understanding of where the DC stops and the AC picks up so to speak, but I'm sure hoping a new or recharged 12v will do the trick.