Parked Battery Life

[David M]

Hello all,

I have a 2013 Interstate Ext Lounge with, what I consider a very short battery life. My house batteries runs down if I don't drive it for one day with only the propane solenoid and the refrigerator on in its lowest setting. I have the solar panel option and this happens even in sunny Southern California weather! I thought this was normal and was considering replacing the 50w solar panel with a 160w panel and adding a second 160w panel in front of the fan. However, I just saw a You Tube ad by Dave Arbogast that stated that the batteries lasts for 5 days with the refrigerator on. Is this true!?!? Thanks in advance.
David

[Lily&Me]

Hmmmm. We had the same problem, back in our early days.

Not the guru on these things that many people are, but this is what we learned.

Your battery has to be fully charged for it to work to its' full capacity. I can't explain this, as I haven't the technological expertise, but this is what we were told by those who know. . We make sure we are plugged in to electricity for several days if we are going to be camping without electricity for any length of time.

Having done that, 4 days or so with frig on and careful use of lights is doable for us off our coach battery.

If you haven't been plugged in and charging for several days, that may be your problem. You may never get your battery above a low charge, then it dies on you quickly.

I believe the extended charging is something that needs to be done regularly, and that's what we do-----either at the house or in a campground.


Maggie

[David M]

Thanks Maggie, I will try that. I use my Interstate as a daily driver so I don't usually plug it in to shore power. I recently plugged it in overnight because I didn't drive it that day and the batteries went down below 40%, and didn't want to let it sit that way over one more night.

[Boxster1971]

Maggie is right on. The solar panel does not fully charge the batteries. Plugging in to 120V AC power for several days is the only way to ensure the batteries are fully charged. The Magnum Inverter/Charger has an
automatic 4-stage charging process designed for the AGM batteries. It takes many hours to get to the final stage depending on how far the batteries are depleted. The is the description of the final stage for the Magnum Owner's Manual:


"Full Charge (Battery Saver™ mode):

The fourth stage occurs

after four hours of

float charging. The Full Charge stage maintains

the batteries without overcharging, preventing excessive loss of
water in

flooded batteries or drying out of GEL/AGM batteries. In

this stage, the charger is turned off and begins monitoring the
battery voltage. If the battery voltage drops low (

≤12.7 VDC),

the charger will automatically initiate another four hours in

float
charge."

The Lifeline batteries should also get the special high voltage equalizing charge on a regular basis. See the Magnum Controller manual for instructions on how to initiate an equalizing charge as recommended in the Lifeline battery owners manual.

Also the propane solenoid is likely drawing more than the refrigerator if you leave it on for long periods of time. I consider this a real weak link in the Airstream design. Several people have installed a second propane switch inside the coach on the control panel to better manage the use of propane.

Good Luck,
- - Mike

[David M]

Thank you Mike! The problem with plugging it in for 2 days is not being able to drive it for 2 days ha ha ha.

[Lily&Me]

Consecutive overnights would probably do the trick, too.


Maggie

[Protagonist]

I had a problem when I first got my Interstate. Could not figure out the source of the parasitic draw. In my research and experimentation, here's what I found…

1 - You have to park it with the propane solenoid off. It draws about 0.75 amps, or 18 amp-hours a day.

2 - You have to park it with the inverter/charger set to "charge only". The inverter bypasses the battery cutoff, and if you have it set to auto/invert, you'll be drawing power from the batteries to power the television. The television uses power even when turned off, because it has to be able to receive signals from the remote control to turn it on. Also, if you turn on the refrigerator, it will work in 120vAC mode if the inverter is set to auto/invert.

3 - Going along with (2), the inverter itself draws power from the batteries when set to auto/invert.

4 - You have to make sure the antenna amplifier is turned off. That draws quite a bit, too, though I don't know exactly how much.

5 - The various control panels in the curbside overhead locker all draw 12v power, too, as does the thermostat for the a/c, whenever the battery switch is in the "on" position. The draw for each control isn't much, but it all adds up.

Just to be on the safe side, I also turn off all of the AC circuit breakers when parking, though it's not strictly necessary since if the inverter is set to "charge only" the circuits wouldn't have power anyway.

With just the refrigerator on (say to cool it down before packing for a trip) the house batteries will be depleted to about 85% charge in 24 hours, even with the solar panel working. I never have to cool it more than overnight, though, since the food is the very last thing I load before heading out.

If I shut off everything, I can leave the Interstate parked for a month or more without depleting the house batteries; the 50w solar panel does a fine job of keeping the house batteries topped off. That's assuming, of course, that I park it with the house batteries fully charged. You should consider the solar panel as a float charger only, and use the generator to charge the batteries if they start to get depleted. You should run the generator every so often anyway to keep it in good shape, so that's not much of a hardship.

I actually have more of a problem with the chassis battery, due to the alarm system I installed. If I let it sit for two weeks without running the engine at all, I have to jump-start it due to the battery drain (though the alarm system still has enough power). Another thread on the AirForums addressed auxiliary chassis batteries, and I'm planning to have one installed after my next trip. That should help.

[Bob4x4]

Add more solar with a good controller and you will be fine.I say make your rig work the way you want to use it.Don't let the rig change you

[Protagonist]

Originally Posted by Bob4x4

Add more solar with a good controller and you will be fine.I say make your rig work the way you want to use it.Don't let the rig change you

But make sure there's enough room on the roof for more solar before buying. Between the Sirius antenna, the MaxxFan shroud, the bathroom vent, the air conditioner, the television antenna, and the awning case, there's not a lot of real estate left on an Interstate's roof for more solar panels. You might be able to upgrade from the factory 50w to something a bit larger, but you're unlikely to fit a second panel unless it's right up front. Though you might surprise me, so don't let me stop you from trying.

Also, Mercedes Benz says the weight capacity of the roof is 300 pounds for the high-roof Sprinters. Make sure the total weight of everything up there (a/c, awning, solar, etc) doesn't exceed 300 pounds.

And remember, you also need to leave enough room for a person to get up on the roof to maintain everything.

[lewster]

Try these for your Sprinter. I have 5 on my roof (see avatar): GS100 Solar Panel | Solar Panels

[Boxster1971]

Protagonist is correct there is not much room on the roof of an Interstate to add more solar panels. At a minimum you would have to relocate/remove the Sirius and TV antennas to make room additional panels on roof. I've looked at this a lot because more solar seems a good option. The GS100 panel from AM Solar looks like one of the best on the market.

Another approach that some folks have used is portable solar panels set up on the ground. But they can only be set up when you are parked in an area with enough room and security.

If your Interstate is your daily driver the coach batteries will get enough charge, of course depending on how much you drive each day. When you don't drive it will need to be plugged in if you want to run the coach systems like the refrigerator and inverter.
You can try to add things to the Interstate to make it work the way you want to use it. In my opinion the Interstate was designed to be plugged in regularly. I stayed three days in Key West dry camping using only the refrigerator. The single 50W solar panel seems to keep up pretty well, but it was a losing game. I was able to run the propane generator several times a day. Mostly after sunset to run the AC cooling down the coach.
I also use mine as a daily driver when I’m home. But I shut off all the coach systems buy turning off the coach Battery Disconnect Switch. The Kenwood Entertainment/Nav unit then is powered by the Chassis battery via the Sprinter key switch.
- - Mike

[Rsknutson]

Hello All,

The wife and I have been reading this forum for almost a year now just for the education! Having just purchased our first ever RV and it being a new 2014 AS Interstate Lounge Ext, we hope to learn much more and will gladly contribute when and where we can. We just completed our maiden voyage, a one-niter close to home to check out the plumbing, power,etc... and all the other bells and whistles. From the sound of this thread my initial instinct to keep the shore power connected while in the driveway at home is on target, yes? Question...are the house batteries charging when connected to shore power as well as from the trickle charge from the solar panel?

Thanks,
Ralph & Shin

[lewster]

I BEG TO DIFFER!

"5.4 Charging
Charging Lifeline® AGM batteries is a matter of replacing the energy removed during discharge plus a little extra to make up for charging inefficiency. The amount of energy necessary for complete recharge depends on the depth of discharge, rate of recharge, and temperature. Typically, between 102% and 110% of the discharged ampere-hours must be returned for full recharge.
The most efficient method of charging Lifeline® AGM batteries is to use a 3 stage charging profile. In the first stage, a constant current is applied until the voltage reaches a pre-set limit. The first stage is often called the Bulk charging stage. In the second stage, the voltage is held constant at the same pre-set limit until the charging current tapers to a very low value, at which point the battery is fully charged. The second stage is often called the Absorption charging stage. A voltage limit of 14.3 volts ± 0.1 volts (7.15 ± 0.05 volt for a 6 volt battery) should be used when the battery temperature is 77°F (25°C). The battery is fully charged when the current drops below 0.5% of the battery’s rated capacity (0.5A for a 100Ah battery). In the third stage, the charging voltage is reduced to a lower value that minimizes the amount of overcharge, while maintaining the battery at 100% state of charge. This third stage is often called the Float charging stage. A float voltage of 13.3 ± 0.1 volts (6.65 ± 0.05 volts for a 6 volt battery) should be used when the battery temperature is 77°F (25°C). The charging voltages at other temperatures can be determined from the following table:

Nothing is mentioned about a conditioning charge:

5.5 Conditioning
Conditioning should only be done when the battery is showing symptoms of capacity loss due to extended time in a partial or low state of charge condition. This could be caused, for example, by low charging voltage for an extended number of charge cycles, or by repeatedly charging to only 90% state of charge.
NOTE: Some chargers use the term Equalizing Charge instead of Conditioning Charge. An Equalizing Charge is generally applied to flooded lead acid batteries that are susceptible to acid stratification. However, an Equalizing Charge may be used to provide a Conditioning Charge for Lifeline® batteries as described below.
To apply a conditioning charge, first go through the normal charge cycle to bring the battery to full charge. The conditioning charge should then be applied by charging for 8 hours. At 77°F (25°C), the conditioning voltage should be set at 2.58 VPC (15.5 volts for a 12 volt battery). The conditioning voltage at other temperatures is shown in Table 5-2. By using the temperature- compensated conditioning voltage, batteries that are not in controlled temperature environments may be conditioned without bringing them to room temperature. If temperature compensation is not available, it is best to bring the battery as close to room temperature as possible before applying the conditioning charge.

Note the bold paragraph... Lifelines should only be conditioned when these symptoms are evident.....NOT ON A REGULAR BASIS!

Further, any quality multi-stage solar charge controller WILL fully charge your batteries. If you are not getting a full charge from your controller, either there is a problem with your solar system, your charger is defective, or it is not capable of doing the proper charging job it was intended to do!

There are many solar charge controllers (specifically MPPT controllers) that do a proper job of keeping your batteries properly charged.

REGULAR APPLICATION OF A CONDITIONING CHARGE WILL EVENTUALLY DESTROY YOUR LIFELINE BATTERIES PREMATURELY!

[Boxster1971]

Apologies for my poor choice of using the word “regularly” to apply an equalizing/conditioning charge. Your info is right from the Lifeline Technical manual. It sounds like David M is already experiencing capacity loss and is not getting to 100% charged state in addition to taking the coach batteries down to 40%.

In an Airstream Interstate unless you plug into 120V AC or run the propane generator for hours you won't get a full charge on your coach batteries.

Solar charging via the Atkinson controller used in my Interstate stops at 13.9 Volts. There is no 3-stage charging from this charge controller and it doesn't even start charging until the battery voltage is at 12.4V or below 75%. In my opinion Airstream did not install a quality multi-stage solar charge controller.

I have only used the equalizing/conditioning charge twice in the past 10 months after trips where I went through many charge cycles with batteries getting to less than 100%.

- - Mike

[David M]

Oh my goodness. I have so much to learn here. I'm going to have to read each post many times for me to digest it all. This is what forums are all about! So much good information being shared. I love it! Keep em coming...
David

[Protagonist]

Originally Posted by lewster

The most efficient method of charging Lifeline® AGM batteries is to use a 3 stage charging profile.

I'm sure the information about Lifeline batteries applies to all AGM batteries. Sure hope so, because my Interstate didn't come with Lifeline batteries. They are Discover Energy® Traction Dry Cell EV24A-A batteries, which according to the product literature are AGM batteries despite the words "dry cell" in the name.

http://www.discover-energy.com/sites...ts/EV24A-A.pdf

A lot of the information and tables on the PDF data sheet are meaningless to me since electrical isn't my field of expertise, but the Self-Discharge Characteristics table on pg. 2 seems to indicate that, for typical New Orleans summers (i.e. using the 104°F line), even if the batteries are stored with no parasitic current draw, they'll still self-discharge to 80% capacity in less than two months, or to 60% in about 5 months. That's without a solar panel to help maintain the charge, of course.

[lewster]

Originally Posted by Boxster1971

Apologies for my poor choice of using the word “regularly” to apply an equalizing/conditioning charge. Your info is right from the Lifeline Technical manual. It sounds like David M is already experiencing capacity loss and is not getting to 100% charged state in addition to taking the coach batteries down to 40%.

In an Airstream Interstate unless you plug into 120V AC or run the propane generator for hours you won't get a full charge on your coach batteries.

Solar charging via the Atkinson controller used in my Interstate stops at 13.9 Volts. There is no 3-stage charging from this charge controller and it doesn't even start charging until the battery voltage is at 12.4V or below 75%. In my opinion Airstream did not install a quality multi-stage solar charge controller.

I have only used the equalizing/conditioning charge twice in the past 10 months after trips where I went through many charge cycles with batteries getting to less than 100%.

- - Mike

Mike,

There is a good chance that you will never bring your batteries back to 100% capacity if they only receive 13.9 VDC when they should be getting 14.2-14.4 VDC in the bulk and acceptance phases.

I would look at several causes:

• your solar charge controller needs to be replaced with a fully operational 3-stage charging unit capable of sending at least 14.2 VDC (temperature dependent) to your house batteries

• your solar panel(s) don't have the open circuit voltage capacity to send enough voltage to the charge controller to accomplish the above (if your oanels do not emit at least 17 VDC, this will not happen. This is due to voltage drop from numerous sources like too many or improper connections, too small a wire gauge used in the installation, or simply a charge controller incapable of fully utilizing the input from the solar array

• your panels are either dirty or sit in some shadow when in full sunlight. This also has a negative effect on the voltage output capacity of the solar array.

Every time you perform a conditioning charge on Lifeline AGM batteries, you risk crossing the 15.5VDC (temperature compensated at 75ºF) threshold, creating an over-charging situation which will allow the hydrogen sulfide gas which usually recombines into the glass mat to escape the battery thru the one way valve.

Once this happens, you have permanently reduced the charge capacity of the battery with no way to restore it, as liquid that has been removed from the glass mat can not be replaced.

Proper charging is critical to the extended life of an AGM battery. I have clients with large Lifeline battery banks (6 X 8D) currently in their 8th and 9th years of continual service that are still above 95% capacity and have never been conditioned.

[David M]

Update: After leaving the coach plugged into shore power all weekend, the panel showed 100% this morning! I'm so exited as I've never seen this before. It looks like you were all correct in that I just needed to leave it plugged in for a few days. I'll keep you all updated. BTW, both my batteries were replaced with new ones in May 2013 and I washed my solar panel a few weeks ago. The batteries were replaced by Lifeline because the dealership didn't keep the batteries charged while on the lot; so they wouldn't hold a charge for more than a few minutes. This could be why I'm particularly sensitive about battery life 😃 Airstream Los Angeles is taking physical measurements of the real estate on top of their Interstate on their lot to see if a second panel can be mounted. If not, I may have to simply replace the existing panel with the highest wattage panel I can find. I'll keep you all posted. I've also started seeing flexible solar panels with self adhesives on it that may be an option. I don't know if they can be custom sized to fit on our Interstates and how efficient they are, but they look attractive from a weight standpoint.
David

[Boxster1971]

Thanks Lew,
Very good info. I’ll refrain from using the equalizing/conditioning charge from now on. My 2013 Interstate has the Magnum MMS1012 Inverter/Charger. I checked all the settings and they are correct for the Lifeline batteries in my coach. Hopefully the Magnum worked properly and didn’t over charge my batteries when I did the equalizing/conditioning charge.

I’m trying to get more info on the Atkinson PVCM20D that Airstream installed in my Interstate. The user manuals supplied don’t have much detail. I don’t know how much voltage is going to controller when solar charging. I’ll have to get a meter on the PV panel input side of the controller which is not easy to get at under the rear lounge seat on my unit. The remote control panel displays the battery voltage. This is all the info on charging voltages from the Atkinson manual:

SEALED BATTERY *Blue Jumper Clipped *
THRESHOLDS: @ Room Temperature 15-308C
On @ 12.4VDC, Off @ 13.9VDC
Accuracy +/- 0.1V DC

Best I can tell it operates according to these basic specs. My panels are clean, but I only get direct sunlight for about 4 hours a day when I normally park in my driveway. When I was in Key West I got max sun every day.

The Atkinson PVCM20D is only about a $65 unit so I doubt that is does anything like 3-stage charging or MPPT. I’d probably be better off replacing this controller with a better unit before I think about adding more solar panels.

- - Mike

[Boxster1971]

Opps the Atkinson Specs should read:
THRESHOLDS: @ Room Temperature 15-30 deg C