The Details - Service Bulletin 164 - Battery Draw

[coder]

This service attempts to eliminate the parasitic current draw by the Magnum Inverter/Charger when the Interstate is being stored. See this earlier thread for more info.

DO I NEED THIS?

This repair turns off the Magnum Inverter/Charger when the battery disconnect switch is used to turn off the van’s electrical systems. The repair applies to Interstates for entire 2014 and 2015 model years, and part of the 2016 year (vehicles in the VIN range of 302701 through 304627).

If you park the van unconnected to 110V power, yeah, you probably want the repair.

WHAT IS THE REPAIR?

The repair takes about 45 minutes.
1. Disconnect 12V
2. Mount the solenoid on the roadside panel of the electrical compartment
3. Disconnect red 12V 00 power cable to the Magnum Inverter
4. Attach that power cable to the solenoid large terminal
5. Attach a new length of 00 red between the other solenoid large terminal and the Inverter
6. Attach 2 blue and white 12ga. wires to the solenoid small terminals
7. Connect blue to an open spot on the fuse panel. Connect white to ground. Insert 5A fuse

Solenoid is SAS 4202, specification 200A continuous, SPST-NO. Solenoid is normally open, and closes when the coil is energized. If I’ve looked up the right part, coil is 14.5 ohm, so it draws 850 mA when closed.

WHAT DOES IT DO?

For affected vans, the Magnum was left energized even when the van was parked (batteries disconnected using the battery disconnect switch). The Magnum uses hella power when it is sitting energized unused. You don’t need it to be energized when the van is parked, obviously. So how much power does it suck up? If your van is parked without 110V power, the Magnum will drain away about half your batteries’ capacity in 10 days, 8 Ah each day, or about 5% each day.

Your solar panels might be able to undo the drain of the Magnum. Depending on how sunny it is, your solar panels might contribute 8 Ah of energy to your batteries, preventing any drain from the Magnum. Keep in mind, however, that solar only contributes during the day, so even if your solar keeps your batteries fresh, the batteries are being drained of 4 Ah at night and refilled when the sun is up. That constant cycle of night-time drain and daytime refill, every day and night, is not good for the batteries.

WHAT IF I DON’T HAVE IT DONE?

Keep your van plugged in. Keep in mind that if you cannot plug your van in for a period, you might have to refresh the batteries every week or so to prevent damaging them. Without the repair, the Magnum may drain the battery bank below 50% in about 10 days.

IS THERE ANY DOWNSIDE TO THE REPAIR?

I’m glad you asked. Airstream, in all its wisdom, chose a cheap relay to turn off the Magnum. When using the van, the Magnum will be energized and the relay will draw about 850 Ma. That’s no problem if you are connected to 110V power, but may be a problem boondocking.

Before the repair, the Magnum would use 300 to 400 mA by itself. After the repair, the Magnum and the relay together use more than 1.2 A, three or four times the draw of the Magnum alone. Boondocking, you’ll get a lot less time from your batteries. The Magnum and relay together will use about a fifth of your total battery capacity per day.

CAN I FIX IT SO I CAN STILL BOONDOCK?

There are a couple of things you can do:

1) When you are off 110V power, using the van, but are not using the Inverter, pull its fuse. You don’t want to do that too much, however, because eventually the fuse holder will wear out.

2) Install a switch so that the relay and Magnum can turned on and off manually.

3) Replace the crappy SAS-4202 with a latching or low-power relay. There is at least one low-power, solid state relay that is a direct drop-in replacement for the SAS-4202. If you go with a more common Intellitec latching relay, you may still have to add a switch to turn the relay on and off manually.

[coder]

I wanted to keep this thread clean, for discussion about SB-164. Personally, I was discouraged and unhappy when I found out the details of this service bulletin (the 850 mA relay). It’s yet another low-quality, inappropriate, cost-saving Airstream approach to an Interstate problem.

I posted a short update in another thread on the current status of my attempts to get my 2014.5 Interstate van fixed under warranty, for all the various problems I've had with the Interstate.

[Boxster1971]

Coder - thanks for posting these details on SB-164. I agree that this change is only useful when storing your Interstate. For boondocking it has made battery drain worse. The Interstate in stock for is just not a good unit for boondocking.


- - Mike
2013 Lounge EXT on 2012 Sprinter

[Dalwyn]

Originally Posted by coder

3) Replace the crappy SAS-4202 with a latching or low-power relay. There is at least one low-power, solid state relay that is a direct drop-in replacement for the SAS-4202.

Do you know what the part number is for this direct replacement?

Thanks

[gghayes]

i plan to boondock with our interstate and am interested in hearing what other comments will be made about this post.

[Boxster1971]

Originally Posted by gghayes

i plan to boondock with our interstate and am interested in hearing what other comments will be made about this post.

Which model/year is your Interstate? If you plan to boondock you will need to be very conservative with battery power use or add more solar power with more batteries. I added 400 watts of solar to my van with four GS-100 panels from AM Solar. Also increase batteries to 440 AH using 6v Lifeline AGMs and upgraded the inverter to a 2000 watt Magnum unit.

This setup has given me very good independence from plugging into power. I only need to run the generator for air conditioning. For example I left Florida with a full refrigerator on Tuesday morning, stopped at a Cracker Barrel in Georgia overnight using the microwave off the inverter for dinner. Then stayed two days in a friends driveway in North Carolina using the furnace to get warm. Today I stopped for lunch in Virginia and again used the microwave off the inverter for lunch. I just stopped for the day at 3 pm and my batteries are 100% charged from the solar panels.





- - Mike
2013 Lounge EXT on 2012 Sprinter

[c21]

I thought turning off the inverter at the remote killed the drain on the invertor. Which is it?

[Boxster1971]

Originally Posted by c21bill

I thought turning off the inverter at the remote killed the drain on the invertor. Which is it?

Turning off the inverter at the remote does reduce the drain caused by the load search function, but there is still a standby drain of 0.3-0.4 A. The SB-164 was issued to stop that drain when the disconnect switch is off. See this original post on SB-164 to read the first page of the actual document from Airstream.
http://www.airforums.com/forums/showpost.php?p=1716074


- - Mike
2013 Lounge EXT on 2012 Sprinter

[tlundell]

Not to contaminate the topic of this thread, but could someone circle back briefly to the option of a house battery terminal cutoff switch, which would stop all draw...but other consequences (2015 Interstate Grand Tour)?

[Boxster1971]

Originally Posted by tlundell

Not to contaminate the topic of this thread, but could someone circle back briefly to the option of a house battery terminal cutoff switch, which would stop all draw...but other consequences (2015 Interstate Grand Tour)?

I installed a total cut-off switch (Blue Sea 500A) that stops all power to the inverter and all other 12V DC house loads. I left the solar and BIM isolation relay connected to the batteries so all batteries continue to get solar charging when parked. The only negative consequence is that the Kenwood radio starts at a setup screen when reconnecting the 12V power. It's not a big deal, just a minor inconvenience.


- - Mike
2013 Lounge EXT on 2012 Sprinter

[Boxster1971]

This article from FitRv can give you some good information on house battery management. It's not about an Interstate, but many of the system loads discussed apply to the Interstate.
http://www.thefitrv.com/rv-tips/watt...ur-class-b-rv/


- - Mike
2013 Lounge EXT on 2012 Sprinter

[coder]

I have some real-world experience now with SB-164, and it isn’t pretty. The relay is installed. I am using it exactly as Airstream intended, so I am not pulling the fuse.

We took the truck out last weekend to a state park without hookups, and ran on batteries from Friday evening until Sunday lunchtime. We ran the fridge all the time, and used the TV for a couple of hours.

The Inverter/Charger frequently failed to turn on. I was using Airstream’s Battery Disconnect switch to try and save some battery power. A lot of the time, when turning everything on, the Magnum remote display just stayed powered off. Tried a few things to get the Inverter/Charger to come on reliably, and couldn’t. Gave up on using the Inverter Saturday afternoon, couldn’t get it powered on.

And, yes, it probably does add a significant load while using the truck. We were down to 11.8V or 11.7V before even 24 hours had passed.

[Boxster1971]

Originally Posted by coder

I have some real-world experience now with SB-164, and it isn’t pretty. The relay is installed. I am using it exactly as Airstream intended, so I am not pulling the fuse.



We took the truck out last weekend to a state park without hookups, and ran on batteries from Friday evening until Sunday lunchtime. We ran the fridge all the time, and used the TV for a couple of hours.



The Inverter/Charger frequently failed to turn on. I was using Airstream’s Battery Disconnect switch to try and save some battery power. A lot of the time, when turning everything on, the Magnum remote display just stayed powered off. Tried a few things to get the Inverter/Charger to come on reliably, and couldn’t. Gave up on using the Inverter Saturday afternoon, couldn’t get it powered on.



And, yes, it probably does add a significant load while using the truck. We were down to 11.8V or 11.7V before even 24 hours had passed.

The Interstates delivered from Airstream, even with SB-164, are simply not designed for this type of use unless you run the generator for several hours each day. Also draining your batteries to 11.8V destroys them as this is below 25% SOC (State of Charge).

Your expectations are just beyond the capabilities of Airstreams system design. In my view this is not a lemon issue. You should buy a Roadtrek Etrek is you want to use your van this way.


- - Mike
2013 Lounge EXT on 2012 Sprinter

[UKDUDE]

As I reported on another thread about SB-164, I had it installed and my batteries are now pretty useless. I was pretty upset about it since I've been babying the batteries since new and always had the Interstate plugged in when at home.
But I always try to look on the brighter side of things: this is forcing me to call on Lew's services to upgrade my batteries and solar, and he will clean up the SB-164 mess and make it suitable for dry camping. Thank you Lew!

[coder]

Originally Posted by Boxster1971

The Interstates delivered from Airstream, even with SB-164, are simply not designed for this type of use unless you run the generator for several hours each day.

The Interstate could easily be used for a weekend in a state park or national forest if Airstream hadn't borked this repair.

The original problem with the Interstate was about parking. The Interstate couldn't be parked for a month.

Airstream fixed that by doubling the battery drain when we're using the van, and screwing up even that. After SB-164, the Inverter doesn't work any more.

Perhaps Airstream might put someone who graduated from high-school to work on this. Getting the Interstate to a point where it can be both 1) parked, and 2) used for a weekend is not complicated. Beyond Airstream, though.

Does everyone think I'm a nut for wanting this van to be useable for a weekend? Is everyone else driving from hotel to hotel? Or spending $thousands on replacing everything?

[K9CarCrate]

I was extremely disappointed (pissed) that Airstream misleads its boondocking capability feature. It simply doesn't. Like Boxter, I had I all changed out, down to the pathetic wiring, 300W solar panels, new bluesky charging system, 2000A puresine inverter, and 440Ah of battery backup. I have true-shutoff and recently added a toggle switch that shuts off the navigation system while the Battery Disconnect Switch is on. Out of the box the AI is designed to boondock in your driveway and not much more.


Sent from my iPhone using Airstream Forums

[Dalwyn]

Originally Posted by K9CarCrate

I had I all changed out, down to the pathetic wiring, 300W solar panels, new bluesky charging system, 2000A puresine inverter, and 440Ah of battery backup.

I would love to have my unit changed out like this. I am not able to do this myself, what is the best way to determine if a service center is qualified to do this type of work?

[unifreck]

Contact Lewster on AirForums

[Boxster1971]

Lew Faber is on this forum regularly. He goes by "lewster"
http://www.airforums.com/forums/memb...ter-10325.html

Here is his tag line...

Lew Farber-RVIA Certified Master Tech...ABYC Certified Master Marine Electrician MASTER TECH ENERGY SYSTEMS, INC.
AM SOLAR FACTORY AUTHORIZED SALES & INSTALLATIONS ...AMS LITHIUM BATTERIES...MAGNUM INVERTERS ...LIFELINE AGM BATTERIES…COMPLETE ELECTRICAL UPGRADES

[Titus]

To K9CarCrate
Which wire do you put the switch on to turn off the navigation system without turning off all power to the radio? We like to be able to play music while stopped - but don't need to navigate anywhere while parked at a campground (or Walmart). Killing all power requires us to re-do the set-up parameters (language, etc.) each time - something I 'd like to avoid.