Deep Cycle Batteries

[live4thedash]

Is there a trick to deep cycle batteries. I replaced the two 6 volt batteries in April. I've used the motorhome a few times since then. The last time being late May. Heading out for a trip in the near future decided to check the batteries and they are dead. I don't get it. I have the 12V switch turned off and the door as you enter. All of the other switches are off too. So I don't get why they are dead?

Any ideas?
thanks

[HiTech]

Try a drive to see of you can start them charging back up. It will take days plugged in to get back to full charge.

[live4thedash]

Trogan T-105 batteries, newly purchased in April. I just assumed by pressing the disconnect switch it would be fine. Didn't realize alarms would still draw on it. Kind of weird it would empty them in a month and half though? Normal? Threw a charger on the batteries but it wouldn't take. Wonder if just taking it for a ride will charge them back up.
thanks

[RJsfishin]

If you have a decent converter, why not leave it plugged in, and not have to worry about the batteries.

[Popsie]

In our RV, even with the house battery disconnect switch set to off, the smoke alarm, propane alarm, etc. still draw on the battery.

[MrWizard]

you didn't name the mfg and model

but on many, the LP and CO detectors are independently hard wired and are NOT disconnected, unless you disconnect the battery ay the main cables

[2oldman]

And you're sure they were fully charged before disconnecting?

[mena661]

Not all disconnect switches actually disconnect everything. The one in my MH disconnects all house loads from the battery BUT I can still charge/float my batts with the converter.

[MEXICOWANDERER]

A correct battery cutoff switch is about the diameter of a soup can, has a big metal handle and copper bolts on the other side that a 9/16" wrench fits. Such a switch will be located not more than a couple of feet away from the batteries.

What you believe is happening when you "switch everything off" isn't happening.