6V batteries will self-discharge, when new, at 1% a week if you have nothing connected to them. 4-5 months without being hooked to a charger is way too long, especially if your coaches disconnect switch is on. You need to keep your rig plugged in when at home or get some solar and let that keep your batteries charged. I have a gas MH also and here are my typical draws:
12V only devices
1. Step Switch On - .33A
2. Radio (Standby or On) - .13A
3. Antenna Amp On - .1A
4. Water Pump On – 7A
5. Fantastic Fan (we have two)
a. Low – 1.26A
b. Med – 1.86A
c. Hi – 2.75A
6. Sat Dish
a. On/Standby – 2.28A
b. Seek – 2.68A
7. Fridge Gas - .55A (Pos 5)
8. Awning Wind Sensor - .06A
9. CO Detector - .05A
12V draw when inverter is on
1. Inverter No Load Cord Unplugged - .36A
2. Inverter Breakers Off - .3A
3. Appl and Light Breakers On – 1.25A
4. Bed Unplugged – 1A
5. Rear Entertainment System
a. Standby – 1.64A
b. On – 3.88A
6. Front Entertainment System
a. Standby – 1.95A
b. On – 13.6A
7. Front TV – 6.18A
Things add up. The standby draw from the entertainment system alone will suck your batteries dry. BTW, cell phones draw about .6A each.