Battery Cutoff Switch

[Silverbee]

Have a 2007 Safari SE-20ft. Need some help understanding just how the battery cutoff switch works and just what it does.

[fltlevel510]

Tom,

Personally, we use the on position whenever we are using the Airstream whether 110v is available or not.

We use the store position when the Airstream is not in use and not plugged into shore power to keep phantom electrical drain from things like the LP detector, radio, etc.

This is directly out of the Owner's Manual:

BATTERY DISCONNECT SWITCH
The disconnect switch is used to separate the batteries from the 12-volt distribution panel and converter charging system.

When the switch is turned “use” (on) and the trailer is plugged into a 110-volt shoreline, the 12-volt distribution panel will receive power from the converter and the batteries will be charged through the converter charging system.

When the switch is turned to “store” (off) and the trailer is plugged into a 110-volt shoreline, the 12-volt distribution panel will still receive power from the converter, but the batteries are disconnected from the system. The batteries will not be drained with the switch in the store position. The converter will not charge the batteries with the switch in this position.

The charge in the 12-volt batteries is replenished when towing from the tow vehicle alternator through the 7-way cord. This charge will go to the batteries no matter which G position the Battery Disconnect Switch is in.

[Wingeezer]

Originally Posted by fltlevel510

Tom,

Personally, we use the on position whenever we are using the Airstream whether 110v is available or not.

We use the store position when the Airstream is not in use and not plugged into shore power to keep phantom electrical drain from things like the LP detector, radio, etc.

This is directly out of the Owner's Manual:

BATTERY DISCONNECT SWITCH
The disconnect switch is used to separate the batteries from the 12-volt distribution panel and converter charging system.

When the switch is turned “use” (on) and the trailer is plugged into a 110-volt shoreline, the 12-volt distribution panel will receive power from the converter and the batteries will be charged through the converter charging system.

When the switch is turned to “store” (off) and the trailer is plugged into a 110-volt shoreline, the 12-volt distribution panel will still receive power from the converter, but the batteries are disconnected from the system. The batteries will not be drained with the switch in the store position. The converter will not charge the batteries with the switch in this position.

The charge in the 12-volt batteries is replenished when towing from the tow vehicle alternator through the 7-way cord. This charge will go to the batteries no matter which G position the Battery Disconnect Switch is in.

I discovered by accident that even when the switch is turned to store there is still some parasitic drain on my batteries. (2005 Classic 30)

I found this out because I was connecting the batteries one day with the switch in "store" position and noted a spark when I hooked up teh battery terminals. That indicates current flow. I didn't attempt to measure the current & have no idea what was being fed.

I could be mistaken, but I seem to recall someone on this forum saying that not everything is disconnected when in the store position - although I don't see the logic to that.

Maybe my store switch is defective?

In any event what I did to easily be sure that the batteries were truly disconnected when I wanted them to be was to install quick disconnects onto each battery that just require a quick turn of a knob on the terminal clamp to disconnect or reconnect the battery.

Two such quick disconnects needed, they cost me $5 each as I recall from Harbor Freight and work fine.


Brian.

[Pahaska]

The wire for the propane detector bypasses the kill switch. This is because, once powered up, the propane detector deteriorates if it is not powered constantly.

If you download a manual from Airstream.com and look at the wiring diagram, you will find the bypass wire shown.

Later manuals do not have the wiring diagrams. You have to go back to about 2005 to find the diagram. You can extrapolate from one model to another since they are all pretty much the same.

[thecatsandi]

The propane detector and the break-a-way switch and the Electro-hydraulic brake actuator (if you have one) are all hot all the time. My tongue jack was hot as well.

[Wingeezer]

Originally Posted by Pahaska

The wire for the propane detector bypasses the kill switch. This is because, once powered up, the propane detector deteriorates if it is not powered constantly.

If you download a manual from Airstream.com and look at the wiring diagram, you will find the bypass wire shown.

Later manuals do not have the wiring diagrams. You have to go back to about 2005 to find the diagram. You can extrapolate from one model to another since they are all pretty much the same.

Hmm, that's interesting - I should read the blurb that came with my propane detector to see if it gives any warning of that.

Doesn't seem good as I expect many people who cannot store their trailers at home, me included, remove batteries from their trailers when stored for a while and take them home to put them on charge.

Wonder how much it affects the life of the propane detector? I guess smoke detectors, CO detectors, and propane detectors should probably be changed any way every 5-10 years or so in any event as a precaution.

Brian.

[Wingeezer]

Originally Posted by thecatsandi

The propane detector and the break-a-way switch and the Electro-hydraulic brake actuator (if you have one) are all hot all the time. My tongue jack was hot as well.

Seems a lot of our trailers may be wired a bit differently with respect to that isolation switch.

I suspect my propane detector is still connected, as something is certainly drawing current in teh store position.

I wouldn't be surprised if the brake emergency switch is still connected too, that would make sense, although of course it would not normally draw current unless tripped, in which case you;d lose your batteries in short order - and maybe your brake magnets!

I do know for a fact however that in my case, the tongue jack on our trailer won't work if the isolation switch is in store position. At first I thought my tongue jack had become defective until I learned that! Maybe the PO has altered the wiring for some reason.

Brian.

[dznf0g]

I think that only the propane detector draws current in the store position. (at least according to my manual) It makes sense that the breakaway switch would have power, but no draw unless polled out. Of course this would mean that the actuator would have available power....but does it have any parisitic "keep alive" circuits, or is it "dead" unless the breakaway switch is pulled?

[thecatsandi]

Originally Posted by dznf0g

I think that only the propane detector draws current in the store position. (at least according to my manual) It makes sense that the breakaway switch would have power, but no draw unless polled out. Of course this would mean that the actuator would have available power....but does it have any parisitic "keep alive" circuits, or is it "dead" unless the breakaway switch is pulled?

The computer in the Actuator is always on. Slight draw.

[dznf0g]

Originally Posted by thecatsandi

The computer in the Actuator is always on. Slight draw.

That makes perfect sense. Now for the million dollar question. Has anybody tested the total parisitic draw when the switch is off? If I'm only going to store it for 2 weeks at the lot (no shore power available) do I need to disconnect the batteries? 3 weeks? a month? (I doubt it). Assuming 2 healthy deep cycle batteries. I have them disconnected now for a 2 week lonely absence.

[richinny]

similar question:
http://www.airforums.com/forums/f449...why-67735.html

[dznf0g]

I think I'll just install the quick disconnects at the posts and stop "anal"izing it!

[nayl]

I have a strange situation when using my battery cut-off switch. If I turn the switch off it cuts off any 12 volt functions, then if I turn the switch back on all 12 volt functions are still non-functioning. The only way to restore the 12 volt functions is to plug into an external electric source. The battery can have a full charge when this occurs.

Also, my battery does not charge while the tow vehicle is running. I changed the fuse in the tow vehicle battery line thinking this was the problem. If the battery runs down while dry camping we are out of luck until we plug into electric.

Any ideas?

[thecatsandi]

Originally Posted by dznf0g

That makes perfect sense. Now for the million dollar question. Has anybody tested the total parisitic draw when the switch is off? If I'm only going to store it for 2 weeks at the lot (no shore power available) do I need to disconnect the batteries? 3 weeks? a month? (I doubt it). Assuming 2 healthy deep cycle batteries. I have them disconnected now for a 2 week lonely absence.

If you disconnect the batteries and have an actibrake or simular you need to re-sync with the brake controller when you hook the TV back up to the trailer.

[thecatsandi]

Originally Posted by nayl

I have a strange situation when using my battery cut-off switch. If I turn the switch off it cuts off any 12 volt functions, then if I turn the switch back on all 12 volt functions are still non-functioning. The only way to restore the 12 volt functions is to plug into an external electric source. The battery can have a full charge when this occurs.

You switch is likely not functioning. The Converter goes to ? I forget since I re-wired my high current DC. Mine is on a large (60A) breaker into the high current buss.

Originally Posted by nayl

Also, my battery does not charge while the tow vehicle is running. I changed the fuse in the tow vehicle battery line thinking this was the problem. If the battery runs down while dry camping we are out of luck until we plug into electric.

Any ideas?

What make and model TV do you have? Some need an additional fuse installed. Some will still drain the TV battery when the ignition is off and others will not. The charge line only provides a modest amount of current. That current depends on how much extra capacity your charing system has for your trailer. It takes all day of towing and Solar to re-charge my batteries after running the furnace for one night.

[nayl]

We have a 2002 International AS.

I thought I had this problem solved as I took it to a local dealer and they did some re-wiring, but the problem has resurfaced after I had to replace the hitch jack (same dealer). Could they have mistakenly un-done the previous fix?

As it was explained to me prior to the previous fix, there is a sylenoid that needs to be kicked on to allow the battery to charge from the tow vehicle. If the battery is dead then external power must be supplied to kick in the sylenoid in order for the vehicle to charge the battery. The only way this is possible is through external power. To avoid this the sylenoid had to be by-passed.

[thecatsandi]

The in and the out wires on the solenoid may be reversed. The normal way they are wired is the switch compleats the circuit to ground. This energizes the solenoid and it closes. Check the solenoid and ses if it has one or two small posts. If it has one I will bet money the battery and the load are reversed. If is has two little posts then the positive and negative are likely reversed.