House batteries drain

[arboldt]

What should I check to solve house batteries draining?

Yesterday morning batteries were at 12.8 VDC, MH left unused for 30 hours, and batteries were at 12.0 VDC this afternoon. We are at my sister's, where we can pull the MH into her driveway and plug it in when needed but we can't block her driveway overnight.

2004 Mountain Aire gasser. 2 - 6V deep-cycle batteries are 10 months old. The controller/charger has an add-on iQ4 adapter. I've installed a solar panel controller that's hooked up to the battery, but the panel is stored and not connected.

I've checked that there are no lights on in any bays, no lights in the MH itself, and inverter is off. The only things I can identify drawing power are the refrigerator control circuit (the refrigerator itself is running on propane), the LP warning sensor, and the control circuit to extend the steps when I open the door. I don't want to switch the batteries to 'store' because I do want to keep the 'fridge going.

So what am I missing? How do I identify what's using up my power and draining my batteries?

Thanks for helping me know where to look.

[Ricci]

Hi - It depends on your level of competence and what you have for tools. The easiest way to get started is to take an ammeter and put it in line in place of each 12 volt fuse. See if you see any large draws. If so, trace down that circuit until you find the issue. You might also put the meter on the positive cable of the battery to see if in fact there is a large draw or if you are dealing with a battery issue. New batteries can be defective.
Try these and report back.
Tom

[GaryKD]

Hi arboldt,
Is the inverter on? Make sure the inverter is turned off. The inverter will drain 2 coach batteries pretty quickly. Also, if nobody is in the coach, consider turning off the LP gas detector.

[arboldt]

I had the MH on shore power for 48 hours, then disconnected for 1 hour.
Battery level was 13.1 VDC, then I checked each DC circuit: measuring at 20mA with the common lead on the ground, the other lead where the circuit connected. I did NOT pull the fuses, but spanned them from input connection to ground. Newmar labeled each circuit (vs numbering them).

Here's what I found: mA
TV/Stereo (20A circuit) 0
Kitchen (20A circuit) 0
Bedroom (20A circuit) 0
Security (20A circuit) .01
Wrap Lights (20A circuit) .01
Slideout lights (20A circuit) .01
Refrigerator (5A circuit) 1.52
Furnace (20A circuit) 0
Living Rm/Entry (20A circuit) 0
Bath (20A circuit) 0
Monitor Panel/Water Pump (20) .01
Slideout Motor (20A circuit) .02
Fantastic/Water Heater (10A) .04
AC Controls (7.5A circuit) .01
Satellite (7.5A circuit) .02

I was expecting a reading for the refrigerator control (it's powered by propane when off shore power but still needs controls active).
I also expected a slight draw from the monitor panel.

While I did not expect the other draws, the total amperage is slight (.12mA).
Although there is a satellite dome on the roof, the previous owner took the control box; we don't know if there is a dish up there or not. The TV BOMB (box of many buttons) is off. The inverter is off so both TVs are off.
The thermostat is off, so furnace and AC circuits are all off.
The water heater is off (both propane and shore power switches).
The fantastic vent fan is off.
The water pump is turned off.

One thing I did not check was the solar controller, directly connected to the battery but with the solar panel not connected.

So the question is, do these small draws account for an average drop of .5 VDC of battery power over an 8 hour time? If not, what else should I check?

[Soppy]

Originally Posted by arboldt

I had the MH on shore power for 48 hours, then disconnected for 1 hour.
Battery level was 13.1 VDC, then I checked each DC circuit: measuring at 20mA with the common lead on the ground, the other lead where the circuit connected. I did NOT pull the fuses, but spanned them from input connection to ground. Newmar labeled each circuit (vs numbering them).

Here's what I found: mA
TV/Stereo (20A circuit) 0
Kitchen (20A circuit) 0
Bedroom (20A circuit) 0
Security (20A circuit) .01
Wrap Lights (20A circuit) .01
Slideout lights (20A circuit) .01
Refrigerator (5A circuit) 1.52
Furnace (20A circuit) 0
Living Rm/Entry (20A circuit) 0
Bath (20A circuit) 0
Monitor Panel/Water Pump (20) .01
Slideout Motor (20A circuit) .02
Fantastic/Water Heater (10A) .04
AC Controls (7.5A circuit) .01
Satellite (7.5A circuit) .02

I was expecting a reading for the refrigerator control (it's powered by propane when off shore power but still needs controls active).
I also expected a slight draw from the monitor panel.

While I did not expect the other draws, the total amperage is slight (.12mA).
Although there is a satellite dome on the roof, the previous owner took the control box; we don't know if there is a dish up there or not. The TV BOMB (box of many buttons) is off. The inverter is off so both TVs are off.
The thermostat is off, so furnace and AC circuits are all off.
The water heater is off (both propane and shore power switches).
The fantastic vent fan is off.
The water pump is turned off.

One thing I did not check was the solar controller, directly connected to the battery but with the solar panel not connected.

So the question is, do these small draws account for an average drop of .5 VDC of battery power over an 8 hour time? If not, what else should I check?

If you're measuring current (amps or ma ) the meter has to go is series with the load. The only way to do this is by pulling the fuse and then connecting the meter across the fuse terminals. If you measure from the chassis ground to the fuse , you have to be measuring volts.
There may also be circuits that use self resetting circuit breakers that would be connected to the coach batteries.
The best way to find the draw would be to remove the pos battery cable and connect an amp meter from the pos post to the cable. You could have a draw in excess of 10 amps.

[arboldt]

Originally Posted by Soppy

If you're measuring current (amps or ma ) the meter has to go is series with the load. The only way to do this is by pulling the fuse and then connecting the meter across the fuse terminals. If you measure from the chassis ground to the fuse , you have to be measuring volts.
There may also be circuits that use self resetting circuit breakers that would be connected to the coach batteries.
The best way to find the draw would be to remove the pos battery cable and connect an amp meter from the pos post to the cable. You could have a draw in excess of 10 amps.

So I re-tested, removing each fuse and measuring mA between the fuse block ground and the in-connection for each circuit. Here are the results:

Circuit / reading on 20mA Scale

TV/Stereo 0
Kitchen 0
Bedroom 0
Security 0
Wrap Lights 0
Slideout lights 0
Refrigerator 0.54
Furnace 0
Living Rm/Entry 0
Bath 0
Monitor Panel/Water Pump 1.33
Slideout Motor 16.00
Fantastic/Water Heater .80
AC Controls 0
Satellite 0

Most are the sameas before, with 3 circuits showing significant test differences; I do not understand them and would appreciate any insights on why / what to do about them:
For the Fantastic Vent, when I put the meter probes on the leads with the fuse removed, I could hear the vent motor cranking the vent open. With the fuse in place, the motor was off and silent. Can't understand why using the Amp meter would activate the vent motor.
The biggest draw is the slideout motor circuit. I tested with the bedroom slide all the way out (easier to get to the fuse panel). I put the slide back in, waited 4 hours, and tested again with the same result.

So with slide motors off, why would they be drawing so much power?
What should be my next step?

Thanks.