Electrical system ?? for an AI newbie

[jodie1425]

Just purchased a 2018 AI - when your van is not in use and it can be plugged into electrical outlet , is it safe to leave it plugged in? Thank you

[Pahaska]

Yes. Plug it in and leave the battery disconnect in the "on" position. All recent AI, with the Magnum charger/inverter, can be stored plugged in.

I keep my 2014.5 in covered storage with 30a service. Plugged in and refrigerator on. It is my "man cave," just like my former Airstream trailers. I often stop in after lunch to take a quick nap or watch a DVD without being disturbed. It is also my refuge when my wife's book club meets at my house.

[FlyFishinRVr]

Originally Posted by Pahaska

Yes. Plug it in and leave the battery disconnect in the "on" position.

I'm not sure how this translates to the '18 because I don't know if they have the same Main Disconnect switch that we have in previous model years, but the bottom line is to leave the "house" power on when you're plugged into shore power. In previous model years you know it's on because there is a red LED next to the switch. If the LED is on, house power is on. Hopefully the new '18's have something similar.

Oh, and congrats on the new Interstate!

[jodie1425]

Thank you so much for responses!! I know this won't be the last question , as we are so green to this vehicle, but so excited for the adventures to come!! Thanks again

[VAtom]

An alternate life view. My 2014 charges just fine when plugged in and has battery disconnect activated.
The inverter/charger is one of the uses that receives power with the disconnect activated, along with the propane detector, the lounge motor, the BIM, the solar controller and maybe the tank heater. (but not the propane switch)
The Magnum senses shore power and it monitors charge status unless the battery is disconnected at the source.
Theoretically you can always leave it plugged in and the Magnum doesn't hate you enough to ruin your battery. Apparently other chargers are not so magnanimous.
One thing about activating the battery disconnect is that if your shore power is accidentally unplugged, the battery drain is slower....ask me how I know.

[FlyFishinRVr]

Originally Posted by VAtom

An alternate life view. My 2014 charges just fine when plugged in and has battery disconnect activated.

Just to avoid confusing someone new to the Interstate, this is only true on models built before 2016. Starting with the '16's, the house power MUST be left on or the Magnum won't charge the batteries. This little tidbit caught a lot of dealers out as they didn't know this, and as a result they killed a lot of coach batteries (much to the annoyance of new owners with house batteries that wouldn't hold a charge ).

[busb2]

This came up on another thread and I noted tha my 2017 AI Tommy Bahama charges with house batteries on or off. I tested it after reading that it would not charge with house batteries off, so I suggest the OP test his to see how his works.

[VAtom]

Originally Posted by FlyFishinRVr

Just to avoid confusing someone new to the Interstate, this is only true on models built before 2016. Starting with the '16's, the house power MUST be left on or the Magnum won't charge the batteries. This little tidbit caught a lot of dealers out as they didn't know this, and as a result they killed a lot of coach batteries (much to the annoyance of new owners with house batteries that wouldn't hold a charge ).

Jackson Center Roulette

[FlyFishinRVr]

Originally Posted by busb2

This came up on another thread and I noted tha my 2017 AI Tommy Bahama charges with house batteries on or off. I tested it after reading that it would not charge with house batteries off, so I suggest the OP test his to see how his works.

Even the schematic shows it's not possible to charge the batteries with the Main Disconnect off (i.e. red light is OFF). On the '16's and beyond, AS put in a second electro-mechanical switch just like the primary switch to fully disconnect the Magnum from the batteries. This replaces the old SB-164 solenoid.

I just checked the '17 Tommy B owner's manual and the schematic on pg 9-17 is identical to the other '17's. You'll see two switches, one labeled House Main Disc, the other is Inverter Main Disc. Both have the same trigger (Master Disc Sw), so when that switch is off (i.e. red LED OFF), both switches open and completely isolate the inverter/charger from the batteries. The only way yours could be charging with the Main Disc switch off is if your Inverter Main Disc switch isn't working (manually disabled or something electrically is wrong).

[busb2]

I have owned three AI's and one thing is consistent for all three. The owners manuals seem to contain inconsistencies and variances with how the units were actually built. My current AI was obviously not wired as referenced. Also, there seems to be differences in how the fusion unit was wired in various same year units as noted in the long chassis battery discussion in another thread. My unit was on the dealers lot for at least three months and I tested the house and chassis batteries before delivery and they were perfect. ????

[FlyFishinRVr]

Originally Posted by busb2

I have owned three AI's and one thing is consistent for all three. The owners manuals seem to contain inconsistencies and variances with how the units were actually built. My current AI was obviously not wired as referenced. Also, there seems to be differences in how the fusion unit was wired in various same year units as noted in the long chassis battery discussion in another thread. My unit was on the dealers lot for at least three months and I tested the house and chassis batteries before delivery and they were perfect. ????

Good to know your dealer maintained your batteries properly. Mine did as well. Sadly, many did not and there were lots of frustrated new owners posting on the forums.

I know that some Fusions were incorrectly wired. Mine is one of them. The schematic shows the power for it should come from the house supply, not the chassis, yet mine pulls from the chassis. I'll fix it this winter.

As far as the Inverter Main Disc switch is concerned, if you can charge your 2016 or newer coach with the Main Disc wall switch off (red LED OFF), you've got a problem with your Inverter Main Disc switch, which means your Magnum is pulling from your house batteries any time the coach is sitting unplugged.

[stast01]

Sometime in late 2015/Early 2016 Airstream made a change to fully disconnect the Magnum as part of the Master Disconnect Switch. In 2015 AI and earlier years, disconnecting the Battery Switch (at the sliding door) still left a load of about 800 milliamps on the house batteries as the Magnum inverter shunt remained connected. That load also included the CO and propane detectors. The problem with that approach was that you HAD to leave the AI connected to shore power, or your batteries would deplete entirely in about two weeks, even with the disconnect switch off. Sometime in late 2015, Airstream modified the circuitry to disconnect the inverter entirely when the battery switch was off, and retrofits were provided for earlier models that amounted to a solenoid that disconnected the inverter shunt as the BD switch was toggled. I found the retrofit not altogether satisfactory, as the solenoid got quite hot and also used 200-300 milliamps to stay closed when the house was "on". I replaced the solenoid with a heavy duty "battery disconnect" style SPST switch that allows me to disconnect the inverter load for long term storage as I didn't have access to shore power in my storage facility. If you own a 2015 or earlier and have shore power at your storage facility and keep your rig plugged in (with or without the battery switch on), you don't need to worry about it. With mods done 2016 and beyond, the switch must be on for shore power to charge the house batteries.

[VAtom]

Originally Posted by stast01

I replaced the solenoid with a heavy duty "battery disconnect" style SPST switch that allows me to disconnect the inverter load for long term storage as I didn't have access to shore power in my storage facility.

Thanks for the explanation of the evolution.
I added a high amp disconnect to the battery bank as well and am very pleased with the result. I lose about .01 volt per day or less, so that means it might take 60 days to go from 12.9v (my full charge) to 12.3V (my 50% charge) That's a lot of cushion for me.

All of the battery disconnects (like BlueSea) are for the positive battery cable but all of the experts say to disconnect the ground for storage.
Is this important, or is the + disconnect satisfactory.

[stast01]

Originally Posted by VAtom

Thanks for the explanation of the evolution.
I added a high amp disconnect to the battery bank as well and am very pleased with the result. I lose about .01 volt per day or less, so that means it might take 60 days to go from 12.9v (my full charge) to 12.3V (my 50% charge) That's a lot of cushion for me.

All of the battery disconnects (like BlueSea) are for the positive battery cable but all of the experts say to disconnect the ground for storage.
Is this important, or is the + disconnect satisfactory.

It shouldn't matter--as long as one side of the battery bank is disconnected, the batteries are isolated from any load. My SPST switch only disconnects the inverter shunt. There is still a slight load on the batteries for the propane detector, but I have left my AI stored for 4-6 weeks with no appreciable drain on the batteries.

[LazyDesert]

Hi, i’m A new interstate 2017 owner — i was plugged into 30amp shore power with main disc switched at the door to “DISC” — is the airstream charging in this mode or simply OFF? when I turned the switch to “MAIN” position the fusion came on and rebooted — question is, when i am plugged in should I leave the MAIN DISC switched OFF or leave it ON? And is the fusion wired correctly based on this setting.. i also have a red switch under the passenger seat that disconnects power — should this be off for long term storage? Thanks!!

[Land Stitchy]

We have a 2107 Grand Tour. Switches are different but I think they are wired the same.

If you turn the battery switch off the battery charger will not work. Therefore in storage there would be no reason to be plugged into shore power. If you are going to store with the intention of keeping shore power plugged in and battery charger on you should keep an eye on the main (Mercedes Benz) battery. A number of people have had problems with a strong draw on the main battery and the battery isolator (known better as the "BIM") not managing properly. After a week you might find a dead main battery.

If that is the case you can store the coach with the battery switch off, not plugged in and pull the main battery cutoff plug that is located above the gas peddle. That preserves the main battery.

However, if you pull the main battery cutoff plug you do not want to run the battery charge since it will attempt to charge a disconnected battery and that might cause damage to your charger.

We have only had ours for a few months so this is all a learning curve for us.

[Titus]

And see this thread for why you should not plug into AC or run the generator with the Magnum disconnected from the coach batteries. Some model years apparently protect against that occurring, some don't. I think that is the disconnect that you refer to as being under the passenger seat.
http://www.airforums.com/forums/f240...182891-12.html

[Boxster1971]

Titus - I think you meant to link to this thread.
Electrical burning, heavy smoke w/ 3yr old grandson sleeping in AI

http://www.airforums.com/forums/showthread.php?t=182891