How does the switch in the battery compartment work?

[Cooncatz]

The house battery in the Class-C I recently bought was discharged and I am about to replace it - I have no knowledge of how the switch in the battery compartment works

I assume OFF totally disconnects the house battery from all 12 volt applications.
1. Should I turn the switch off when connected to shore power?
2. Will house battery charge with switch in the OFF position?
3. Should I turn the switch OFF when traveling?
4. Should I turn the switch OFF when RV is not in use?
5. Is the house battery used to start the generator?

[Bobbo]

If it is in the battery compartment, I bet the previous owner installed it.

[Bordercollie]

It might be best to contact the previous owner, if possible, and ask what the switch is for. Older rigs often have DIY fixes and "improvements" that confuse the new owners. Four Winds may have an idea about the switch too.

[SCVJeff]

thestoloffs wrote:

Cooncatz wrote:
The house battery in the Class-C I recently bought was discharged and I am about to replace it - I have no knowledge of how the switch in the battery compartment works

I assume OFF totally disconnects the house battery from all 12 volt applications.
1. Should I turn the switch off when connected to shore power?
2. Will house battery charge with switch in the OFF position?
3. Should I turn the switch OFF when traveling?
4. Should I turn the switch OFF when RV is not in use?
5. Is the house battery used to start the generator?

Every unit could be wired differently, but most follow certain general principles. On this basis, I'd answer:

1. Yes, although it could limit house battery recharging from the convertor.
   
2. See above.
   
3. NO. An absorbtion refrigerator must have 12 VDC power during non-AC powered operation, in addition to gas.
   
4. That's a question of whether or not your unit has parasitic drains (always-on DC items, like LP gas and CO detectors).
   
5. In most cases, Yes. I wouldn't shut off the 12 VDC during generator operation.

All of the above is accurate except #1. When hooked up in a CG you need to leave the batteries On. There are very few, if any converters that deliver clean enough power without the buffering of the battery bank that they were designed to be on the output. Problems anywhere from dim lights to massive hum on the radio, to the TV pre-amp not working, all the way to wiping out the fridge control board among others. When camping or traveling there is really no reason to shut it off. That is a storage mode.

(Edit: iPhone auto-correct)

[CharlesinGA]

Is this some kind of large manual disconnect on the batteries? If so, it is most likely something someone added to the vehicle to use for winter storage. It would allow a portable battery charger to be connected to the batteries without taking cables off.

Most relays/solenoids for the house batteries are mounted away from the batteries (corrosion and all of that stuff) and is controlled usually by a switch near the door where you can reach in and turn it on before you enter, or off after you step down from the coach.

Charles

[cgmartine]

Cooncatz, one other thing...you mentioned the switch in the battery compartment, but the switch you are referring to, at least in most motorhomes, is located at the top and on the side of the cabinet as you enter the side door, on a small panel, along with other gauges. The only thing inside the battery compartment under the stairs is the solenoid. You can hear a loud click when you click on the switch.

[cgmartine]

Regarding #1, in some motorhomes, such as mine, a Fleetwood Tioga, even if I turn the battery disconnect switch to off, when I hook up to shore power, it automatically turns on the switch. so I don't have to bother turning it on. This is most likely to enable the house batteries to maintain a charge. Try it. Once you are hooked up to shore power, attempt to click on the disconnect switch, you will find that it is already on and you also cannot turn it off. But even with the switch off, and away from shore power, you most likely have a carbon monoxide detector that keeps taking power from the batteries, slowing discharging them.

[Cooncatz]

Bordercollile: I have a 31 foot 1997 Four Winds - the only switch if have found is a large rotary switch in the battery compartment - nothing on the control pannel.

[Bordercollie]

It would help to know what brand and model your rig is. I would GUESS that the switch disconnects the house battery during storage or non-use. The "auxiliary battery disconnect switch" is usually located in a control panel in most RV's along with switches and LED indicators for water pump, holding tanks and battery charge levels.

12vdc alarms and appliances that are connected to the house battery, plus self-discharge will cause the house battery to lose charge during storage/non-use. Your RV generator may be connected to your house battery or starting battery for starting it. There may be a momentary "emergency start" switch on the dash that connects the starting battery and house battery in parallel to start the engine or the RV generator when either battery is low. The switch in the battery compartment should be on when connected to shore power and for the house battery to charge from the converter/charger when on shore power, or from the engine's alternator. Recommend you get a cheap digital multimeter from Harbor Freight and set it on the 20 volt DC scale to check whether your new house battery is getting charged by the converter/charger ( should read 13+ volts) when on shore power or (should read around 14 volts) when being charged by the engine's alternator when engine is running. Older converters charge slowly, the engine's alternator charges house battery more rapidly. Your house battery may last 2-3 days of normal use when not connected to shore power unless you run the furnace, it's blower will usually run the battery down overnight. Learn as much as you can about 12 volt electrical system including care and feeding of batteries. Keep battery electrolyte levels above the plates using distilled water.

[thestoloffs]

Cooncatz wrote:
The house battery in the Class-C I recently bought was discharged and I am about to replace it - I have no knowledge of how the switch in the battery compartment works

I assume OFF totally disconnects the house battery from all 12 volt applications.
1. Should I turn the switch off when connected to shore power?
2. Will house battery charge with switch in the OFF position?
3. Should I turn the switch OFF when traveling?
4. Should I turn the switch OFF when RV is not in use?
5. Is the house battery used to start the generator?

Every unit could be wired differently, but most follow certain general principles. On this basis, I'd answer:

1. Yes, although it could limit house battery recharging from the convertor.
   
2. See above.
   
3. NO. An absorbtion refrigerator must have 12 VDC power during non-AC powered operation, in addition to gas.
   
4. That's a question of whether or not your unit has parasitic drains (always-on DC items, like LP gas and CO detectors).
   
5. In most cases, Yes. I wouldn't shut off the 12 VDC during generator operation.