Three house batteries in 2011 Interstate

[BioMedMan]

Hey,

So much information on the forums there's been no need to post questions over the past few months, but got a real puzzler yesterday so here's my first post.

The Airstream dealer in Salt Lake confirmed our suspicions about bad house batteries and problems with the generator running the AC. Nothing new from the various threads in previous posts.

The electric tech found three batteries under the lounge seat... Two Lifeline ATMS side-by-side, and one regular battery below those two. All three connected together! The two Lifelines were probably drained by that regular battery, with sides bulging and heavy corrosion.

We can't figure out why there would be three house batteries. The AI is new to us, and the dealer just said the original owner put about $30K in additional goodies on when it was new. Three solar panels, wireless connections, and all the options Airstream offered with new 2011.

Sent an email to Jackson center asking what was on the original coach, and they sent what looks like a typical spec sheet, so maybe the dealer (Colonial in New Jersey) added the other stuff.

Anyway, we really only want to replace two batteries, not three. Does anyone know why three batteries would be necessary? The tech said he didn't know if two would be enough if three were there originally.

Appreciate any advice or pointers from long-time owners. The AI is still at the Airstream dealer...they're constructing new supports for the new batteries to replace the old, cruddy, broken wood supports originally placed by the factory.

Yoshie
BioMedMan
2011 Airstream Interstate

[Protagonist]

Chances are, the previous owner didn't realize there was a false floor in the battery compartment, with two batteries stacked one atop the other, one above the false floor and one below. Thinking there was only one house battery, he changed it out for a Lifeline, and added a second one alongside, leaving the undiscovered second original battery below floor level.

I very much doubt that Colonial did the work, because they would have known about the stacked house batteries.

There's nothing at all wrong with having three house batteries, as long as they're all the same type and same age and all wired properly in parallel.

[BioMedMan]

Thanks, Protagonist,

The funny thing is that the spec sheet from Airstream lists two house batteries (24v AGM), so it would seem that the third regular battery wasn't original. And it didn't match the other two, which is another problem.

As long as we can get the generator to run the AC in our southwest summers, we'll simply use two new ones and skip a third house battery.

Yoshie
BioMedMan
2011 Airstream Interstate

[LB_3]

I think those are group 24 (size) batteries, not 24v (volt).

Protag's explination makes the most sense to me. Stick with 2 and you should be fine.

[Protagonist]

Originally Posted by BioMedMan

The funny thing is that the spec sheet from Airstream lists two house batteries (24v AGM)

I think you meant Group 24, not 24V.

Just because the spec sheet said Group 24 AGMs doesn't necessarily mean that AGMs were installed. Back in 2010-2011, Airstream was using both AGM and wet-cell in different products, though supposedly all of the Interstates got AGMs. It's remotely possible that wet-cells were installed if the assembly line ran out of AGMs, since it would have been easier to go snag some wet-cells from the trailer assembly line than to go out and buy more AGMs. But that's pure speculation and we may never know for sure.

Also, for my 2012 Interstate, the original spec sheet called for one Group 24 AGM, but two Group 24 AGMs were listed as an option (one of the few option items availableat the time). As it happens, mine did have two, but I couldn't be sure until I disassembled the sofa and opened the battery compartment to see for myself.

[gmillerok1]

Two are fine.

It's obvious the previous owner updated the batteries and solar. Originally, the 2011's all shipped with two AGM's; I have never heard of any 2011 Interstate shipped with anything else because of the great difficulty in checking the fluid levels of a conventional lead-acid battery. Looks like he added 2 more lifelines, and probably just dropped the other one, to increase the amperage. If it was not the same as the two above the floor, then the original owner changed it, and who knows why.

The maybe not so good news is whoever did it, they may have not done the upgrade correctly, with the correct wiring, charge controller, and batteries. If you don't have the knowledge to determine that, it may be worthwhile to find someone who does and redo anything that is not up to what it should have been, and also replace anything that should have been replaced with the upgrade.

Does it still have the Tripplite inverter/charger? That model will destroy your batteries if you leave it plugged in and charging all the time which may have been what happened to the damaged battery. It's a 'dumb' charger, unlike the Magnum inverter/charger put in the 2012's and later models.

My guess is the batteries are shot for whatever reason and since the genset starts off the house batteries, it won't turn over or start with the limited symptoms you described.

[BioMedMan]

Yes, Protagonist, 24 series is what I should have posted. AND the wiring did need to be reconfigured, as well as repairing the plates supporting the new batteries and the old, forgotten battery below.

We still have the original Tripplite inverter, with two new GPL-4CT6VDC golf cart batteries in a series/parallel configuration. Now the generator fires up and AC comes on with nary a flicker of lights, or generator coughing.

My understanding from previous posts on the Tripplite issue [2012 Interstate 3500 inverter question] is "(1) When shore power is connected, set the inverter to "charge only." Shouldn't this prevent overcharging the house batteries? We house our AI in the garage, and keep it plugged into 110V A.

If that's incorrect, how in heaven's name would you know how long to leave it plugged in when the house batteries need to be charged?

While I aspire to a Magnum inverter, it's not in the budget...unless we curtail traveling this year.

Many thanks for all your help. Keep up the good work!

Yoshie
2011 Interstate

[gmillerok1]

Whatever you do, don't leave the Tripplite plugged in 24/7. It will overcharge the batteries and boil off the water causing acid to drip into the box, causing damage, and then unto the floor. I still have rust stains where my previous Roadtrek (with the same model Tripplite and exactly the same lead-acid batteries you now have) did exactly that. What I used to do, before I swapped the Tripplite for the Magnum in my 2011 Interstate, was to charge them up, unplug, check on it in a few days, and charge it up again when the battery lost enough charge. I eventually ran two wires from battery post to an external smart trickle charger and left it plugged in to a connector, and did away with the Tripplite charging altogether, and is what I would recommend you do. This one will save your batteries from damage:

http://www.amazon.com/Deltran-Batter...4TMJWQAF2PVZSB

Running a couple of wires is not every difficult.

[Protagonist]

Originally Posted by BioMedMan

My understanding from previous posts on the Tripplite issue [2012 Interstate 3500 inverter question] is "(1) When shore power is connected, set the inverter to "charge only." Shouldn't this prevent overcharging the house batteries? We house our AI in the garage, and keep it plugged into 110V A.

If that's incorrect, how in heaven's name would you know how long to leave it plugged in when the house batteries need to be charged?

The TrippLite is not a "smart" charger, which means that you have to be the brain.

Setting the inverter to "Charge Only" when you plug into shore power makes no difference, because the inverter/charger detects incoming 120vAC current and automatically switches to charger mode. The only thing that setting the inverter/charger to "Charge Only" does for you is— if shore power is interrupted before the batteries are fully charged, the inverter/charger doesn't automatically switch to inverter mode and drain your batteries. Instead if power is interrupted during charging all 120vAC appliances you have running just stop running until shore power is provided again.

When I'm not using my Interstate, I leave everything off that can be turned off, including the TrippLite, and let my solar panel keep the batteries topped off. But I also make sure the batteries are fully charged, or nearly so, when I park it. The solar panel is an adequate float charger, but it's not a deep-cycle charger unless you upgrade to provide more watts of solar panel than you have amp-hours of battery power.

Since I need to run the generator once a month anyway to keep it in good working order, if the house batteries don't stay fully charged on solar alone (say as a result of several days in a row of cloudy/rainy weather) the generator takes up the slack. When I run the generator, I turn on the TrippLite— on "charge only"— and enough other devices to load up the generator to at least 10 amps but no more than 15 amps (50%-75% load on the generator), which is where most generators are at the peak of their load curve, to provide the quickest charge for the fuel burned.

Plus with my Viper alarm system, I have to drive the van somewhere every two or three weeks anyway to keep the starting battery charged lest the alarm system drain it dead. The house batteries will charge off the alternator through the BIM if the house batteries are low enough to need it.

I have no place to plug in to shore power while the Interstate is stored, so I have never considered how long to plug it in while stored, and I've never needed to because I have so many other charging options. Now that you've made me think of it, I'd suggest while you're parked at home, hook up to shore power and turn on the TrippLite during the overnight hours every Sunday night, regular as clockwork (or whatever day of the week is most convenient for you) and turn off everything you can turn off in between. Then you don't have to worry about it, and you'll have a routine you can remember. Being plugged in and charging for about 7% of every week shouldn't be anywhere near enough to cook your batteries.

[BioMedMan]

Originally Posted by gmillerok1

Whatever you do, don't leave the Tripplite plugged in 24/7. It will overcharge the batteries and boil off the water causing acid to drip into the box, causing damage, and then unto the floor. I still have rust stains where my previous Roadtrek (with the same model Tripplite and exactly the same lead-acid batteries you now have) did exactly that. What I used to do, before I swapped the Tripplite for the Magnum in my 2011 Interstate, was to charge them up, unplug, check on it in a few days, and charge it up again when the battery lost enough charge. I eventually ran two wires from battery post to an external smart trickle charger and left it plugged in to a connector, and did away with the Tripplite charging altogether, and is what I would recommend you do. This one will save your batteries from damage:

http://www.amazon.com/Deltran-Batter...4TMJWQAF2PVZSB

Running a couple of wires is not every difficult.

Do you have to disconnect everything from the battery to use the trickle charger? My experience with trickle chargers is limited to car batteries.

[BioMedMan]

Originally Posted by Protagonist

The TrippLite is not a "smart" charger, which means that you have to be the brain.

Setting the inverter to "Charge Only" when you plug into shore power makes no difference, because the inverter/charger detects incoming 120vAC current and automatically switches to charger mode. The only thing that setting the inverter/charger to "Charge Only" does for you is— if shore power is interrupted before the batteries are fully charged, the inverter/charger doesn't automatically switch to inverter mode and drain your batteries. Instead if power is interrupted during charging all 120vAC appliances you have running just stop running until shore power is provided again.

When I'm not using my Interstate, I leave everything off that can be turned off, including the TrippLite, and let my solar panel keep the batteries topped off. But I also make sure the batteries are fully charged, or nearly so, when I park it. The solar panel is an adequate float charger, but it's not a deep-cycle charger unless you upgrade to provide more watts of solar panel than you have amp-hours of battery power.

Since I need to run the generator once a month anyway to keep it in good working order, if the house batteries don't stay fully charged on solar alone (say as a result of several days in a row of cloudy/rainy weather) the generator takes up the slack. When I run the generator, I turn on the TrippLite— on "charge only"— and enough other devices to load up the generator to at least 10 amps but no more than 15 amps (50%-75% load on the generator), which is where most generators are at the peak of their load curve, to provide the quickest charge for the fuel burned.

Plus with my Viper alarm system, I have to drive the van somewhere every two or three weeks anyway to keep the starting battery charged lest the alarm system drain it dead. The house batteries will charge off the alternator through the BIM if the house batteries are low enough to need it.

I have no place to plug in to shore power while the Interstate is stored, so I have never considered how long to plug it in while stored, and I've never needed to because I have so many other charging options. Now that you've made me think of it, I'd suggest while you're parked at home, hook up to shore power and turn on the TrippLite during the overnight hours every Sunday night, regular as clockwork (or whatever day of the week is most convenient for you) and turn off everything you can turn off in between. Then you don't have to worry about it, and you'll have a routine you can remember. Being plugged in and charging for about 7% of every week shouldn't be anywhere near enough to cook your batteries.

What a great suggestion! Once every seven days sounds reasonable, even better than a trickle charger. I drive the van at least once a week, and with three solar panels that should help keep the batteries charged, too, as long as the sun shines.

And I'm saving up for a Magnum.

Yoshie
2011 Interstate Lounge

[73shark]

Originally Posted by Protagonist

Plus with my Viper alarm system, I have to drive the van somewhere every two or three weeks anyway to keep the starting battery charged lest the alarm system drain it dead. The house batteries will charge off the alternator through the BIM if the house batteries are low enough to need it.

My solar panel keeps both the house and chassis batteries charged. Surprised that yours doesn't charge the starting battery. Or is the Viper drain too much for the solar panel to keep up with?

[Protagonist]

Originally Posted by 73shark

My solar panel keeps both the house and chassis batteries charged. Surprised that yours doesn't charge the starting battery. Or is the Viper drain too much for the solar panel to keep up with?

I suspect the Viper alarm system drain is too much for the dinky 50watt solar panel. I don't really mind. I've never had occasion to park my Interstate for more than three weeks without driving it somewhere anyway, so it's no great hardship.

[73shark]

But it looks like the BIM should switch to the chassis battery when it drops below the house batteries. (I think that's the way it works)

[Protagonist]

Originally Posted by 73shark

But it looks like the BIM should switch to the chassis battery when it drops below the house batteries. (I think that's the way it works)

Doesn't on mine. A mere 50w of solar alone isn't enough of a charging source to trigger the BIM.

[73shark]

Somehow it does on mine.

[lewster]

Originally Posted by 73shark

But it looks like the BIM should switch to the chassis battery when it drops below the house batteries. (I think that's the way it works)

The BIM will only connect the 2 battery banks when one battery falls below the pre-set low voltage point………...AND……….. there is a charging source present. It will not (or SHOULD NOT) connect the 2 banks with no charging source operating.

The charging source could be the vehicle alternator, generator, solar or shore power.

[73shark]

Originally Posted by lewster

The BIM will only connect the 2 battery banks when one battery falls below the pre-set low voltage point………...AND……….. there is a charging source present. It will not (or SHOULD NOT) connect the 2 banks with no charging source operating.

The charging source could be the vehicle alternator, generator, solar or shore power.

So in Protag's case, something must be wrong if the solar keeps the house batteries charged but not the chassis battery?

[gmillerok1]

Originally Posted by BioMedMan

Do you have to disconnect everything from the battery to use the trickle charger? My experience with trickle chargers is limited to car batteries.

No, it won't hurt a thing. But I would turn the battery disconnect to OFF just the same as there is no reason not do, and turn the Tripplite to OFF as well. I ran two wires to the battery posts-one positive and negative, to the rear bumper, spliced in to one of the battery tender's push-together connectors, and simply plugged them in, and then plugged the battery tender into AC. I kept it this way 24/7 when stored.

No more worry. I just unplugged it when I was ready to roll. I used the same connector to plug in a portable solar as well on occasion to boost the solar charge while boon-docking.

[lewster]

Originally Posted by 73shark

So in Protag's case, something must be wrong if the solar keeps the house batteries charged but not the chassis battery?

Not necessarily. His solar might not have sufficient output to signal the solenoid to close and link the batteries……definitely no where near that of an alternator or other charging source.

Also, I don't believe that the earlier Interstates used the Precision Circuits BIM, but rather a battery separator from Sure Power which has a different modus operandi.

Perhaps Protag could jump in and clarify which device he has……...