"Dead" Batteries

[ArcherTC]

Hello all -- we are new owners of a 2017 AI Grand Tour, our first RV. Left the unit for 9 days, under cover, plugged into 110v A/C outlet (10amp). Returned to find that the breaker had blown so no power to the rig ... don't know how long. I had not done anything to isolate the batteries since I expected shore power while I was gone.

Reset the breaker for the A/C outlet to find a red light on the Magnum Remote and message "FAULT - NO COMM". Chassis battery reads 11.5v, house batteries no reading at all. Initially engine would not start.

Hooked up a charger to the chassis battery for a couple of hours and got the engine started, pulled the rig out into sunlight hoping for some boost from the solar panel.

The FAULT on the ME-MR cleared. With the engine running chassis and house batteries read 13.8v. Ran the engine for 30 minutes at idle, then hooked up shore power and turned off the engine. The inverter/charger seems to be working properly, battery charge rapidly climbing (currently 12.2v).

I've probably missed some readings that might be clues. I did see a reading of 8.5v for the house batteries when I got monitoring back online. I don't know if this could be right as they've recovered to 12.2v with about 90 minutes of charging.

I'm wondering if I've got a faulty component or just had some parasitic drain (do I understand that SB-164 is standard on the new coaches now?). Seems odd to me that both the house and chassis batteries dropped in this short time.

What should I shut down in the future to minimize the risk of this recurring? The clearest message is that I clearly don't understand this electrical system!

Thanks in advance for any help!

[FlyFishinRVr]

Originally Posted by ArcherTC

Hello all -- we are new owners of a 2017 AI Grand Tour, our first RV. Left the unit for 9 days, under cover, plugged into 110v A/C outlet (10amp). Returned to find that the breaker had blown so no power to the rig ... don't know how long. I had not done anything to isolate the batteries since I expected shore power while I was gone.

Reset the breaker for the A/C outlet to find a red light on the Magnum Remote and message "FAULT - NO COMM". Chassis battery reads 11.5v, house batteries no reading at all. Initially engine would not start.

Hooked up a charger to the chassis battery for a couple of hours and got the engine started, pulled the rig out into sunlight hoping for some boost from the solar panel.

The FAULT on the ME-MR cleared. With the engine running chassis and house batteries read 13.8v. Ran the engine for 30 minutes at idle, then hooked up shore power and turned off the engine. The inverter/charger seems to be working properly, battery charge rapidly climbing (currently 12.2v).

I've probably missed some readings that might be clues. I did see a reading of 8.5v for the house batteries when I got monitoring back online. I don't know if this could be right as they've recovered to 12.2v with about 90 minutes of charging.

I'm wondering if I've got a faulty component or just had some parasitic drain (do I understand that SB-164 is standard on the new coaches now?). Seems odd to me that both the house and chassis batteries dropped in this short time.

What should I shut down in the future to minimize the risk of this recurring? The clearest message is that I clearly don't understand this electrical system!

Thanks in advance for any help!

Turn everything off except house power, i.e. the main disconnect by the sliding door. This needs to remain on for the charger to actually charge the batteries. With that on and shore power connected you should be fine for weeks or even months.

When not connected to shore power and sitting, things like the refrigerator will drain your house batteries in a few days. I keep mine turned off when I'm not actively using the coach. Also keep the main disconnect off, which will keep most electrical draws off. I also turn off the antenna (in cabinet over driver seat) as that seems to stay on even with the main disconnect off. If you plan to keep it disconnected from shore power for longer than a week and don't have it in the sun, you'll need to run the engine or generator weekly.

If you want to store it longer and not connected to shore power or in the sun, and don't want to worry about starting once a week, use the chassis disconnect by the gas pedal to totally remove the chassis battery from any loads, and I'd recommend using the manual disconnect for the house batteries to similarly remove them from all loads. In this config, just pop by monthly and charge the batteries, either by reconnecting them and running either the engine or generator, or using an external charger (but the house batteries are a pain to get to so I'd recommend just using the on-board charging systems).

[WBS248]

Here is my two cents worth. There is a lot to look for. First never never turn on the inverter unless you must. It kills batteries and if you leave it on they will never recover. I know this because I did it and it cost me $450 for new house batteries. Second make sure that the switch in the back is not switched to both batteries. If it is and you lose shorepower it will kill your car battery and you will not be able to start your van. Battery life and power is something you need to read up on and learn.

[FlyFishinRVr]

Originally Posted by WBS248

Here is my two cents worth. There is a lot to look for. First never never turn on the inverter unless you must. It kills batteries and if you leave it on they will never recover. I know this because I did it and it cost me $450 for new house batteries.

Second make sure that the switch in the back is not switched to both batteries. If it is and you lose shorepower it will kill your car battery and you will not be able to start your van. Battery life and power is something you need to read up on and learn.

What is this "switch in the back" you are referring to? The Interstates have an automated battery separator that will disconnect the house batteries from the chassis battery if there's no charging source detected. The only manual switch in the back is the battery disconnect for the house batteries, which will override the switch by the sliding door......

[WBS248]

There is a red switch underneath the port side seat where the breakers are. That can be turned so that both batteries are engaged. Make sure it is not.

[UKDUDE]

Originally Posted by WBS248

There is a red switch underneath the port side seat where the breakers are. That can be turned so that both batteries are engaged. Make sure it is not.

That sounds like the motorized switch that's controlled by the rocker switch near the sliding door. And it doesn't stop the parasitic drains, mainly from the inverter.


Sent from my iPhone using Airstream Forums

[Gregsch]

I don't have an interstate, I have a classic moho but, many circumstances are the same. Your coach has soo many 12v items that are a potential to drain your battery. Many have a parasitic loss that can add up quickly. In my case I have a car stereo that draws 0.7 amps even when turned off (only draws 1.2 amps when paying music at full volume). I have had several issues like the one you describe. I now have a battery disconnect installed within 4 feet of the batteries that isolates the batteries from all loads. I turn both disconnects off whenever I leave it for more than a day. It is an inconvenience to reset all the presets on the radio every time but, that's a lot easier than dealing with dead batteries especially considering you will only run your batteries all the way out a few times before they will be destroyed.

[WBS248]

Yes you are correct on all counts. But it can be manually switched to draw from both banks which will kill both banks.

[FlyFishinRVr]

Originally Posted by WBS248

But it can be manually switched to draw from both banks which will kill both banks.

Yours must be made differently from mine. On mine, the switch in the back is a funky rotary affair that is electro-mechanical and manually disconnects the house battery from the rest of the coach. The switch by the sliding door activates this, but should it ever fail to do so, you can manually turn the dial and get the job done. On my coach it has no connection to the chassis battery. House/chassis battery connection is handled by the Battery Separator (aka BIM), which is electronic. This will only connect the house and chassis batteries together when there is a charging source that is active. Otherwise, the BIM/BS keeps the two banks separated. The only switch in my coach that can forcibly circumvent the BIM/BS and connect the house and chassis batteries together is the engine start assist switch on the dash, and that's a momentary switch (i.e. you have to physically hold it in place to keep them connected) so there's no worry of ever leaving that in the closed position.

[WBS248]

I don't claim to be an expert. I thought like you that the switch only disconnected the house battery. However when I took the van in for the dead battery the technician told me that I was having problems because the switch was positioned so that all banks (the house and engine banks) were engaged and that was part of the problem. He repositioned the switch to only pull from the house. Now he may have been lying to me and I still would not know. But I was having problems with both banks of batteries. That is all I know.

[FlyFishinRVr]

Originally Posted by WBS248

I don't claim to be an expert. I thought like you that the switch only disconnected the house battery. However when I took the van in for the dead battery the technician told me that I was having problems because the switch was positioned so that all banks (the house and engine banks) were engaged and that was part of the problem. He repositioned the switch to only pull from the house. Now he may have been lying to me and I still would not know. But I was having problems with both banks of batteries. That is all I know.

According to the schematics, he may not have been lying, but unless it was wired wonky at the factory, that is NOT how it is supposed to be connected. AS does a decent job of protecting the house from drawing down the chassis battery via the BIM/BS for the very reason of not wanting owners to get stranded with a dead starter battery.

As long as it's working for you now, that's good news and is a good bit of "community knowledge" of something to look out for. There's a fair chance that if yours was wired like that, the same kid may have wired more that way until someone came along and told him he was doing it wrong......

[ArcherTC]

Thanks to all for contributing to this discussion. I started this inquiry after finding that my shore power had died and all batteries in my 2017 AI were affected. I'd like to ask clarification on a number of questions.

First, my "storage" is as follows: We have a barn where the unit is parked, outside under an overhang. There is a 110v outlet (20A) that I use for shore power. I'd rather not pull the batteries and understand that keeping them charged should protect them from freezing.

I normally do not make a special effort to minimize drain in storage since I have shore power. The problem arose when I was gone for 9 days, returned to find my shore power circuit breaker had blown and there was no power to the rig. House and chassis batteries were drained (see my original post for details please).

Question #1: I put a night light on the circuit I'm using for shore power so it's unlikely it would ever be off for more than a few hours without me noticing. Is it okay to leave the rig as though we're using it as long as shore power is working?

#2: If I go out of town for more than a few days I'd like to minimize the risk to the batteries if shore power were to quit again. However, I want the inverter/charger to be able to keep the batteries charged as long as shore power is active. If I switch off the battery disconnect either with the switch by the door or the manual switch does this disable charging?

#3: Another way to pose Q2: What is the optimal configuration to shut down all power drain yet preserve the charging function of the inverter?

#4: When I go out of town for a few days I could leave the rig out where if would receive sunlight (if the weather man cooperates of course) and also leave shore power connected. If my shore power were to die again would contribution of the OEM solar offset any drain necessitated by leaving the inverter/charger enabled ... ?

#5: One contributor suggested I should turn off the inverter, but I assume that would only be appropriate if I did not have shore power.

Bonus question: I am under the impression that the BIS/BM should have protected the chassis battery when my shore power died. Does this suggest that I have a problem with the electrical system.

BTW, yes I am going to have an electrician install a dedicated 30A circuit for my shore power so hopefully the risk of losing power will be much diminished.

Thank you in advance for any help!

[UKDUDE]

Originally Posted by WBS248

I don't claim to be an expert. I thought like you that the switch only disconnected the house battery. However when I took the van in for the dead battery the technician told me that I was having problems because the switch was positioned so that all banks (the house and engine banks) were engaged and that was part of the problem. He repositioned the switch to only pull from the house. Now he may have been lying to me and I still would not know. But I was having problems with both banks of batteries. That is all I know.

The motorized switch can get out of sync with the rocker switch by the door, so when you think you're disabling the coach batteries with that switch by the door, in fact nothing happens - although I think the red light may remain on or blinking. So perhaps the technician resolved that.
But as FlyFishing mentioned, this has no effect on the coach batteries.

Edit: That switch can get out of sync if you force rotate the motorized switch at the rear.

[UKDUDE]

Originally Posted by ArcherTC

Thanks to all for contributing to this discussion. I started this inquiry after finding that my shore power had died and all batteries in my 2017 AI were affected. I'd like to ask clarification on a number of questions.

First, my "storage" is as follows: We have a barn where the unit is parked, outside under an overhang. There is a 110v outlet (20A) that I use for shore power. I'd rather not pull the batteries and understand that keeping them charged should protect them from freezing.

I normally do not make a special effort to minimize drain in storage since I have shore power. The problem arose when I was gone for 9 days, returned to find my shore power circuit breaker had blown and there was no power to the rig. House and chassis batteries were drained (see my original post for details please).

Question #1: I put a night light on the circuit I'm using for shore power so it's unlikely it would ever be off for more than a few hours without me noticing. Is it okay to leave the rig as though we're using it as long as shore power is working?

#2: If I go out of town for more than a few days I'd like to minimize the risk to the batteries if shore power were to quit again. However, I want the inverter/charger to be able to keep the batteries charged as long as shore power is active. If I switch off the battery disconnect either with the switch by the door or the manual switch does this disable charging?

#3: Another way to pose Q2: What is the optimal configuration to shut down all power drain yet preserve the charging function of the inverter?

#4: When I go out of town for a few days I could leave the rig out where if would receive sunlight (if the weather man cooperates of course) and also leave shore power connected. If my shore power were to die again would contribution of the OEM solar offset any drain necessitated by leaving the inverter/charger enabled ... ?

#5: One contributor suggested I should turn off the inverter, but I assume that would only be appropriate if I did not have shore power.

Bonus question: I am under the impression that the BIS/BM should have protected the chassis battery when my shore power died. Does this suggest that I have a problem with the electrical system.

BTW, yes I am going to have an electrician install a dedicated 30A circuit for my shore power so hopefully the risk of losing power will be much diminished.

Thank you in advance for any help!

Let me answer your questions by giving you my experience and situation, since its not that different from yours.

I keep mine in a basement garage beneath the house, permanently plugged in. So we will know if the power goes out. And this arrangement was always good to maintain the batteries. That was up until the dealer had to keep the Interstate for a month while waiting for parts under warranty. (It was last winter and we had no plans to use it at the time - and the dealer gives us a Mercedes loaner for the duration, so why should I complain?).
Anyway, in spite of me reminding them to keep it plugged in all the time, they didn’t, and I found the coach batteries were toast, at least they never held more than 80% capacity.

So, I had Lew install new 6V batteries, and most important, remove SB-164 and install a proper battery cut-off.

A proper battery cut-off is directly wired to the battery terminals, and is quite different from the “cut-off” Airstream installs, which merely attempts to reduce the parasitic drain on the batteries by cutting off some of the load.

What’s SB-164 got to do with it? It’s a Service Bulletin Airstream introduced in 2015 to try to reduce the parasitic drain from the Inverter which remained on even with their battery disconnect in use. It uses a solenoid which in itself has a parasitic drain. In fact in use it gets very HOT, and many of them have been know to fail. Yours is a 2017 so it will have come with SB-164 as standard. In addition, We’ve noted on this forum several owners of recent models have reported their chassis battery has also gone dead. This is really unusual since the Battery Isolation Manager should protect it from the coach batteries. But my guess is that SB-164 failure has something to do with it, perhaps defeating the logic used by the BIM.

You also asked about the solar panel: this is useful when you’re dry camping and want to top up what you’ve used from the fridge, etc. But 100W is way too little to rely on for keeping the batteries topped up, and in addition, the standard solar controller is not smart and cannot maintain the batteries in the way the Magnum can.

In summary, I would recommend you do the same as me: remove SB-164 and install a proper cut-off for when you’re not around to keep an eye on things.

Peter (NOT an expert, just from experience and observation!)

[Boxster1971]

Originally Posted by ArcherTC

Thanks to all for contributing to this discussion. .... I'd like to ask clarification on a number of questions.

Question #1: I put a night light on the circuit I'm using for shore power so it's unlikely it would ever be off for more than a few hours without me noticing. Is it okay to leave the rig as though we're using it as long as shore power is working?

Answer: Yes - it's OK to leave your rig plugged into shore power with the Magnum Inverter/Charger.

#2: If I go out of town for more than a few days I'd like to minimize the risk to the batteries if shore power were to quit again. However, I want the inverter/charger to be able to keep the batteries charged as long as shore power is active. If I switch off the battery disconnect either with the switch by the door or the manual switch does this disable charging?

Answer: Yes disconnecting the batteries using the switch you have will prevent charging the batteries. Leave the disconnect switch ON and just turn OFF stuff like TV booster, LP Valve, refrigerator and all lights. Why did your 20A circuit trip the breaker? You need to know what happened if you intend to rely on it when storing your rig.

#3: Another way to pose Q2: What is the optimal configuration to shut down all power drain yet preserve the charging function of the inverter?

Answer: Leave the disconnect switch ON and just turn OFF the stuff like TV booster, LP Valve, refrigerator and all lights.

#4: When I go out of town for a few days I could leave the rig out where if would receive sunlight (if the weather man cooperates of course) and also leave shore power connected. If my shore power were to die again would contribution of the OEM solar offset any drain necessitated by leaving the inverter/charger enabled ... ?

Answer: Your 100 watt solar panel may not be up to the task if the sun doesn't shine bright. Just store it plugged in and make sure you have a reliable 120VAC circuit.

#5: One contributor suggested I should turn off the inverter, but I assume that would only be appropriate if I did not have shore power.

Answer: Keep inverter function on Magnum turned OFF. The battery charger function is automatic when you plug in, if disconnect is ON.

Bonus question: I am under the impression that the BIS/BM should have protected the chassis battery when my shore power died. Does this suggest that I have a problem with the electrical system.

Answer: It could be a problem as the chassis battery should stay charged when plugged in. Of course that assumes you have the Disconnect ON.

BTW, yes I am going to have an electrician install a dedicated 30A circuit for my shore power so hopefully the risk of losing power will be much diminished.

Good idea to get a full 30A circuit. Do you know why the 20A circuit you are currently using tripped the breaker?

[bob323]

I just picked up my 2017 Grand Tour today and am hoping that I don't experience this problem. Have you determined the cause and the fix? If so, pls share! Thx.

[FlyFishinRVr]

Originally Posted by Boxster1971

Answer: Keep inverter function on Magnum turned OFF. The battery charger function is automatic when you plug in, if disconnect is ON.
Answer: It could be a problem as the chassis battery should stay charged when plugged in. Of course that assumes you have the Disconnect ON.

So......if the inverter is off and all other parasitics that you mentioned are off, in all day sun my batts are staying at 12.8V for the coach and 12.5V for the chassis. This is with the OEM supplied 100W single solar panel. While not ideal, it works. Once a week I run the genny or the engine if I haven't driven it that week.

To make it better, I think another 100W panel plus replacing the Atkinson charge controller with a real 3 phase unit should do the job. With that I don't think it would be necessary to run the genny or the engine to keep the batteries fully charged.

[Boxster1971]

Originally Posted by FlyFishinRVr

So......if the inverter is off and all other parasitics that you mentioned are off, in all day sun my batts are staying at 12.8V for the coach and 12.5V for the chassis. This is with the OEM supplied 100W single solar panel. While not ideal, it works. Once a week I run the genny or the engine if I haven't driven it that week.

To make it better, I think another 100W panel plus replacing the Atkinson charge controller with a real 3 phase unit should do the job. With that I don't think it would be necessary to run the genny or the engine to keep the batteries fully charged.

Based on what I see in the latest wiring diagrams from the owners manual solar should still charge the batteries with disconnect OFF. You should check this to see if it is true on your rig. Then if you want to maximize the solar charging turn the Disconnect OFF. That will eliminate the constant 0.4A standby drain from the inverter/charger.

For your weekly charging "top-off" it would be better to plug into 120VAC for an overnight charge. That would make sure your batteries get to full float once a week. Running the generator or driving for an hour just wont get the batteries topped off as good as the Magnum charger overnight. Remember Lead-Acid batteries take a long time to get that last 2% to full charge. Just make sure you turn the Disconnect back ON when plugging in to charge the batteries.

[ArcherTC]

Thanks Boxster 1971 for the detailed response.
A few last items --

• Shore power: it's failed twice, first time we had a power blip here so I blamed that. More recently I put a small space heater in the RV (probably don't really need it). I plugged it into an outlet not served by the inverter but on the same circuit. I wonder if the load from the heater plus the inverter/charger exceeded the 20A circuit.

• To leave the disconnect ON and turn off the inverter, do I use the power button on the inverter?

• Where do I turn off the LP valve?

Thanks all for helping this newbie!

[lewster]

Originally Posted by ArcherTC

Thanks Boxster 1971 for the detailed response.
A few last items --

• Shore power: it's failed twice, first time we had a power blip here so I blamed that. More recently I put a small space heater in the RV (probably don't really need it). I plugged it into an outlet not served by the inverter but on the same circuit. I wonder if the load from the heater plus the inverter/charger exceeded the 20A circuit.

• To leave the disconnect ON and turn off the inverter, do I use the power button on the inverter?

• Where do I turn off the LP valve?

Thanks all for helping this newbie!

The power button on your ME-MR remote should turn off the inverter section. The charger section will 'wake up' as soon as shore power is present to the inverter.

Your switch for the LP solenoid is presently located behind the black plastic box aft to the right rear mud flap. It is a silver toggle switch that is in the off position when down. It's a PIA to access, which is why I always install a second one in series inside the coach in much more accessible location. Either one disengages the solenoid, but you need both in the ion position to activate it.