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FlyFishinRVr · 04-16-2018, 05:58 PM

Quote:

Originally Posted by Land Stitchy

Hello Dena,

We have the same coach same year. New to use 2 months ago. I have just found an electrical problem that is draining the main (MB) batteries as well. Just found the problem out this weekend so no answers yet. Not trying to hijack your thread but maybe my discovery will spark additional ideas from the group.
I am plug into shore power at home. Both main and aux batteries holding at 13v. On Friday afternoon I ran the coach air conditioner for a few hours - it pulls 15 amps. That drained my main (MB) batteries to the point where I could not start the coach without a jump start. Since I had a big trip on Saturday morning I was in a panic Friday night that I had to cancel. Jump started and all was well Saturday AM.
During the drive we ran the generator for an hour to run AC and cool my guests in the back. When I parked the main batteries were down to 11.0 volts. Fortunately it started a few hours later.
I replicated the problem at home on Sunday. Today I ran the hot water heater and within one hour the main batteries were down to 11.7 volts, put the key in the ignition and it dropped to 11.2 volts. Still enough to start the engine.
Why would running a high amp 110 item drain the MB main batteries? House batteries are untouched at 13.0 volts.

Your coach should still be under warranty, so head to the dealer and have them fix it. Sorry, but that's your best course of action given the situation.

As to "why", it could be several things, but without an hour of time and a multimeter, it's pretty much impossible to say which is actually causing the problem. It could be the transfer switch, the BIM, the Magnum, or any combination (or something else, like a blown fuse...or two).

I will say this however: What ever is causing the problem, it has likely ruined your chassis (Main) battery, so when your dealer diagnoses and fixes the problem, tell them you want a new chassis battery! A battery that goes down to 11.0v is beyond help....

Al and Missy · 04-16-2018, 07:26 PM

Running 120V powered stuff (water heater, air conditioner, etc. should not use 12V, particularly not from coach battery. Is it possible that somehow your shore power and inverter outlets are reversed? Is your inverter on?

Al

Land Sailer · 04-17-2018, 12:38 PM

My next trip to Airstream repair will be to likely have the factory recommended retire as well as a cut off switch to the engine battery. Fingers will be crossed. My stress level has been way too high over this. Thus is such a great forum. Everyone has been so helpful. Thank you.
I'll let you know if the problem is fixed or not after the upcoming repairs.

Protagonist · 04-20-2018, 07:56 AM

Quote:

Originally Posted by Dena m

My next trip to Airstream repair will be to likely have the factory recommended retire as well as a cut off switch to the engine battery.

The is already a cutoff for the chassis battery. It's a red plug down by the accelerator pedal.

Pulling the plug will not necessarily disconnect everything. But it will disconnect most things that draw power from the chassis battery. Try using that disconnect first and see if it solves the problem, before you go to the expense and trouble of wiring in another disconnect.

Land Sailer · 04-20-2018, 10:33 PM

Oh my, this is new to me. Will take a peek to see if this might help you be situation. In the meantime, I've been researching like crazy and sending posted experiences from others to my dealers shop. All ideas are appreciated. Shop manager says that he , too, has been researching cases similar to mine that have been successfully resolved. Ive learned far more that I ever wanted!

Land Stitchy · 05-04-2018, 04:57 PM

Hello Dena,

Any update on your situation? I posted earlier that I had similar situation and have learned more in the last few weeks. I originally thought one of the 110V items was the drain - which does not make any sense at all.

I finally drained my main battery for good - dead. Replaced it with a new battery two weeks ago. We used it all last weekend on a trip with no problems. Brought it home and plugged into the house. I did not realize that the GFI at the house was kicked. Just checked after 5 days and the main battery is dead - 4V. House batteries still at 12.5V.

So I have a similar drain after 5 days on the main battery.

I check the function of the BIM for charging per the manufacturers test procedure and it functions properly on charging (solenoid kicks and charges house or main battery).

I do not think it has anything to do with the Fusion system since it works just fine when the main battery is dead so it is obviously connected to the house bank.

I have a friend that understands electrical systems going through the AS schematic to make recommendations on next steps.

FlyFishinRVr · 05-04-2018, 05:10 PM

Quote:

Originally Posted by Land Stitchy

I have a friend that understands electrical systems going through the AS schematic to make recommendations on next steps.

I'll save your friend some headache and tell you now that the schematics are wrong in many places. I also have a '17, am an electrical engineer, and have fiddled around with the innards of my coach for over a year, so I have some experience in this area. The best way to diagnose what's what is to physically lay eyes on the wiring and components and use a multi-meter to test inputs and outputs. For example, your coach likely has the dreaded SB-164 solenoid installed under the driver side jump seat, but there's no mention of that in the schematics, and the wires going to/from what they DO show are incorrectly labeled. It only goes downhill from there....

Land Sailer · 05-04-2018, 10:58 PM

Spent the entire day at a second Airstream shop who said they have a great electrical guy employed. I had emailed a boat
load of info from the forem, including the Fusion wiring instructions from Airstream. They said they tracked anything pulling from the engine battery and found the Fusion was pulling enough to drain the battery overnight. They rewired and also installed a kill switch from the Fusion to both coach and engine. I'll be taking off in a couple of weeks, and plan to leave the main switch on overnight while parked in my drive. Fingers are crossed.
The insanity of my Airstream ownership is unhealthy. Sure want to have some fun with this RV!

Dena

Land Stitchy · 05-05-2018, 01:28 PM

Dena, curious if you ever noticed if your fusion would work with a dead main battery. My main battery is current dead (3V) but the house is still 12.5v. Fusion works fine and plays CDs. So I am assuming that this porves that fusion is not connect to the main battery and not the source of my problem. Maybe that is a bad assumption. Did you ever notice if fusion would work when your main battery was dead?

FlyFishinRVr · 05-05-2018, 05:42 PM

Quote:

Originally Posted by Land Stitchy

Dena, curious if you ever noticed if your fusion would work with a dead main battery. My main battery is current dead (3V) but the house is still 12.5v. Fusion works fine and plays CDs. So I am assuming that this porves that fusion is not connect to the main battery and not the source of my problem. Maybe that is a bad assumption. Did you ever notice if fusion would work when your main battery was dead?

Not a good assumption.

What we discovered is the Fusion is wired to BOTH banks, at least in some coaches. I think don000 is the only one that has pulled his Fusion and peaked at the wiring, but unfortunately he didn't have a current clamp to figure out which bank was being drawn from and when. His solution was as Dena has done, which is to have a bypass switch installed that totally cuts power to it (cuts power from both banks). Once he had that done, no more problems. I expect the same result in Dena's case.

Land Sailer · 05-06-2018, 11:24 AM

Gosh, I didn't notice if the Fusion would work when the engine battery was dead. Guess my focus was on getting my engine started. As Flyfisher added, my Fusion was wired to both banks. The rv could sit for a few days with the house batteries off and still start, but as soon as I turned the main switch on, the engine battery would drain overnight. The electrical guy who worked on it said there was a large draw on the engine battery from the Fusion (He shared how much, but sorry I can't recall.) but enough to drain the battery overnight.... as it would by leaving the headlights on. I'm feeling good about the kill switch. My house batteries were still operating my frig while the engine battery was dead. You might have the same problem that my rv had. A competent electrical tech should be able to trace where the draw is coming from.
Good luck!

Land Stitchy · 05-06-2018, 01:38 PM

Great input. I will focus on the fusion system. I am still not sure if the Fusion is wired to both systems why it would completely kill the main battery in five days but the house battery is still at 12.5v. I would think it would drain both if it is wired to both. Is it possible that the small charge from the factory installed solar panel would offset the fusion system?

FlyFishinRVr · 05-06-2018, 05:09 PM

Quote:

Originally Posted by Land Stitchy

Great input. I will focus on the fusion system. I am still not sure if the Fusion is wired to both systems why it would completely kill the main battery in five days but the house battery is still at 12.5v. I would think it would drain both if it is wired to both. Is it possible that the small charge from the factory installed solar panel would offset the fusion system?

It depends on where they tied the Fusion into the house side of the electrical system:

A) Before or after the Main Disconnect switch
B) House or chassis side of the BIM

Re. the solar, 5A isn't "small", so yes, it's totally possible that the solar is keeping the house batteries alive while the chassis battery dies, especially given how the BIM works (or doesn't work, depending on your sense of humor.....).

Land Sailer · 05-06-2018, 10:50 PM

Perhaps because there are two house batteries? Never consider my input as one who knows anything about electronics. I report patterns, experiences and knowledge from those who might know what they're talking about! Flyfisher might have a better idea of what might be happening. Truthfully, for lack of knowledge, I focus in what works and what doesn't.
The pattern in my rv was that: main house switch off, engine would start; main house switch on, engine battery dead. Overnight was all it took. Tech recorded significant pull on engine battery from Fusion with house battery on.
Think I'll love this kill switch.

FlyFishinRVr · 05-06-2018, 11:16 PM

Quote:

Originally Posted by Dena m

Perhaps because there are two house batteries? Never consider my input as one who knows anything about electronics. I report patterns, experiences and knowledge from those who might know what they're talking about! Flyfisher might have a better idea of what might be happening. Truthfully, for lack of knowledge, I focus in what works and what doesn't.

The pattern in my rv was that: main house switch off, engine would start; main house switch on, engine battery dead. Overnight was all it took. Tech recorded significant pull on engine battery from Fusion with house battery on.

Think I'll love this kill switch.

Main Disconnect on = Fusion on -> chassis battery dead. Depending on what features you have enabled on your Fusion, it can drain the chassis battery pretty quick. It would be like leaving the keys in your car with the ignition on and your stereo playing. That would kill your car battery just like the Fusion will kill the Sprinter battery. Having a separate cutoff switch ends all that drama.

Land Sailer · 05-07-2018, 10:43 PM

Exactly! Even though the Fusion appeared to be off, it was still draining the engine battery. Which, of course means it wasn't actually off. Kinda makes me want to return to the days when you turned the knob to off, it was actually off! Old fashion isn't always bad.

Land Stitchy · 05-10-2018, 04:59 PM

Dena, looking forward to hearing your results with the Fusion kill switch modification. Here's what I have found in my search - a lot of detail here for those in-the-know to maybe comment.

Based on checking the negative cable of the main battery I have about a 1.6A total draw. If I reboot Fusion it jumps to 1.9 amps. If I run a CD is goes over 2 amps. So sure enough, Fusion is pulling on both the main and house batteries.
I then proceeded to pull fuses on the panel by the left foot of the driver compartment. I pulled fuses one at a time to record the change on the main battery draw.
On the F55/2 bank (reference the Mercedes Fuse Allocation Supplement manual that came with the coach) I pulled fuse #10 and the draw dropped to 0.6 amps and, low and behold, Fusion shut off. That fuse is listed as "Radio 1 or 2 DIN".
I left that fuse out in search of the additional draw and came to fuse #1 on the F55/1 bank that is listed as "Driver's door control unit" and the draw went to 0.0.
For the record, I closed the driver's door and checked again with the same results. So having the Drive Door open does not change the results.
So it appears to fix my problem I need to figure out how to get Fusion off the Main battery bank and figure out what the 0.6A draw from the Driver's Door Control Unit is.
One step at a time......

Land Sailer · 05-11-2018, 09:26 AM

The amount of draw on the main battery is, I think, what the tech found in mine, too. Rewiring as Airstream suggested brought the draw down to the .6 you had. Suppose the new (new to me!) units always have a small draw. That's why I wanted the kill switch. In the good ol days, I could leave my truck parked for 6 - 7 weeks while in the backcountry, come out and just fire up the engine.

Land Sailer · 05-24-2018, 12:55 PM

Just returned from a week of boondocking. Thankfully, the problem with the Fusion wiring seems to have been solved.
Now, as to the solar. I had Airstream add two more solar panels to the one my RV came with, as well as two more house batteries. So now I have 3 - 100 W solar panels and 4 - 12 V batteries.
During my time camping, the batteries just kept depleting. According to the manual of the Sun Explorer charger, the battery voltage needs to be at 11.2 before the system kicks in. Yes, it did start when the batteries were at 11.2 ..... but it was at 4:45 p.m. Hardly enough time to charge anything. When it got dark, the thing shut off and an intermittent buzz that would last for about 4 seconds lasted throughout the night. Turned off the house power in an attempt to stop it, but, of course that didn't work. Anyway, I had assumed that the solar would keep the batteries capped off. Wrong. So I am in the market for a different charger/controller. I know some of you are using Morning Star and others Blue Sky. Do any of you know anything about Go Power? And, what size wire do you recommend for wiring the panels to the charger?

FlyFishinRVr · 05-24-2018, 01:18 PM

Quote:

Originally Posted by Dena m

Just returned from a week of boondocking. Thankfully, the problem with the Fusion wiring seems to have been solved.
Now, as to the solar. I had Airstream add two more solar panels to the one my RV came with, as well as two more house batteries. So now I have 3 - 100 W solar panels and 4 - 12 V batteries.
During my time camping, the batteries just kept depleting. According to the manual of the Sun Explorer charger, the battery voltage needs to be at 11.2 before the system kicks in. Yes, it did start when the batteries were at 11.2 ..... but it was at 4:45 p.m. Hardly enough time to charge anything. When it got dark, the thing shut off and an intermittent buzz that would last for about 4 seconds lasted throughout the night. Turned off the house power in an attempt to stop it, but, of course that didn't work. Anyway, I had assumed that the solar would keep the batteries capped off. Wrong. So I am in the market for a different charger/controller. I know some of you are using Morning Star and others Blue Sky. Do any of you know anything about Go Power? And, what size wire do you recommend for wiring the panels to the charger?

Glad to hear the Fusion problem is sorted.

Ah, the topic of solar charge controllers. What you describe is the reason why my first mod was to pull out the Atkinson "Sun Explorer" and replace it with something better. I want my solar charge controller to be putting energy into my batteries any time there is sun on the panels and room in the batteries for a charge. Waiting like the Atkinson does is just ridiculous and a carryover from flooded battery days. Come on Airstream, pull that bit of tech into the present!!!

As to which controller, personally I think Victron makes one of the best on the market. With 3 panels I'd recommend their SmartSolar 100/30. It will handle the voltage/current from your 3 panels regardless of how they're configured (parallel or series....personally I'd recommend series so you reduce the current in the wiring and therefore can use the stock solar panel wiring), and it has Bluetooth built in so you can set it up and monitor what it's doing via your smartphone or tablet. Having said that, IMO ANY MPPT charge controller will be heaps better than what you have now, so if you want to go with something else, by all means do so. No matter what you use, I think you will see a HUGE improvement in solar energy production and worry a lot less about your batteries. Just keep in mind that in order for solar to work, the van has to be parked in the sun. Depending on where you live, that may present a whole different set of issues.....