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Brawny · 05-04-2016, 04:11 PM

Hi Folks,

We just picked up our 2004 30' Classic last week, and took her camping this weekend for the first time. For the most part, everything worked well, but I have some concerns around battery life, and looking for advice.

The AS has an 80W Go-Power panel and module, which I believe to be working. Under normal conditions, the voltage shown ranges from 12.x to 13.x volts.

With shore power connected, the voltage stays in this range, and the current shown on the Go-Power monitor fluctuates depending on time of day/sunshine, etc.

Monday, on the way home, we stopped for a couple hours and hung out at the beach - napping, reading, nothing that would have used the batteries much. There was plenty of light in the trailer, so no lights on, and we didn't watch TV. I think I had the radio on for a bit, but it was low volume - nothing that would run down the batteries. We got back to town around 7:30 pm, and I dropped my wife off at work, and decided to wait in the parking lot so that she could help me back the trailer in once we got home. It was cold, so I was running the furnace, set at 70F. It was low/mid 40s outside.

I fell asleep with the furnace on, and all lights off in the trailer. When I woke up around 12:30 am, the monitor was showing the batteries in the red. I can't recall what the voltage was - but it was definitely less than 12V. My recollection was that the readings on the Go-Power weren't making any sense - almost like they were random.

I plugged back in to shore power once I got home and unhooked, and yesterday the batteries were back reading 13.x

There are 2 compartments on the front of our AS - and I checked each. The batteries look to be 'Interstate' - they're bright green/white, and appear to be in good condition. I didn't pull them out to check fluid levels, but there wasn't any spilled acid, etc and everything looked clean.

My questions:

This seems to me like the battery ran down really quickly. We wouldn't have even made it a single night if we were boondocking! What should I expect as typical if the batteries were in reasonable shape, and assuming they were whatever the stock battery size is?

Is there a definitive way to tell if the batteries are almost done and in need of replacement? I don't have access to a load tester like they have in an automotive shop.

If I do need to replace the batteries, then I guess I'll need to discuss with our AS dealer to see if they'll give us a break on replacement costs, since we just got the trailer last week, and have only taken it out once. (They did a thorough check of the trailer before we took possession to insure everything was working properly. We may have to discuss whether this counts as 'properly' :-)

If I am going to replace the batteries, I'd like to get something that's going to have good capacity so we can go off grid for a couple days, and works well with the existing 80w panel and Go-Power controller. I've heard folks talk about changing out the charge controller to a 3 stage unit from the stock single stage in order not to boil the batteries. I'd like to avoid throwing money at the trailer right away if possible, but if upgrades make sense, then better to spend at least some money now rather than shorten the life of brand new batteries...

Thoughts? Advice?

kscherzi · 05-04-2016, 05:22 PM

The furnace fan does draw a lot of electricity from the batteries. Five hours of furnace run time could have killed your batteries, especially it they weren't at full charge, or are old, or both. When off grid throw an extra blanket on the bed and turn the furnace off. In addition to the furnace, the water heater, refrigerator, radio (even when off), and so other things are drawing power 24/7. It all adds up.

If camping on batteries alone I'll run mine for 20 minutes in the morning or evening to take the edge off the chill but that's about it. More than that and too much battery capacity is lost.

sgschwend · 05-04-2016, 05:36 PM

Does your panel show energy used? Or at least instantaneous power?

If so why hot run a test on your fully charged battery and she how many amp hours it will produce at lets say a 5 amp load.

FCStreamer · 05-04-2016, 05:44 PM

In boats, batteries last about three years. I changed mine regularly. I would expect having to change my RV batteries every 3-5 years.

Brawny · 05-04-2016, 06:59 PM

Quote:

Originally Posted by sgschwend

Does your panel show energy used? Or at least instantaneous power?

If so why hot run a test on your fully charged battery and she how many amp hours it will produce at lets say a 5 amp load.

Unfortunately, it doesn't. There aren't any buttons to alter the display. It cycles between battery voltage and charging current - I'm assuming from the solar panels.

sgschwend · 05-04-2016, 07:59 PM

Check out the battery threads there are thousands of them here.

You can add a monitor for as little as $20, they work good enough for what you need or you could spend $200 on a real nice one. They all work the same by measuring the voltage drop on a shunt resistor, then they display voltage, current, and power; using an internal clock they can calculate power. Well worth having for a small home that relies on one or two batteries to keep thing working.

More importantly you need a battery charger that works, the OEM on many AS years just doesn't get the job done, the charger/power supply needs to do the job right in order for your battery to last.

kdickinson · 05-05-2016, 10:34 AM

Running the furnace is what did it. My trailer which only has one battery can run the furnace fan on 12v for about 90 minutes before it's spent. I bet your batteries are fine. When I did need to replace my battery I got a deep cycle marine battery and made sure it was fully charged up.

KJRitchie · 05-05-2016, 10:45 AM

There should be date stickers on the batteries. My Interstates were replaced in 3/13 by the dealer. I'd pull them out and check the water levels. Use distilled water to refill. Purchase an external charger that can recharge the batteries fully. Then take the batteries off the charge and let the voltage settle down for a couple of hours. Use a hydrometer to test each cell to make sure there are all reading OK. If your trailer has the standard charger/converter (Parallax) then swap it out for a 3 way charger, like the Progressive Dynamics PD4655. It will charge your batteries to a fully charged condition.

Kelvin

Rgentum · 05-05-2016, 10:58 AM

Nobody's mentioned them yet, so I will: replace your smaller, lead/acid batteries with larger, AGM batteries, which will also require a 3-stage charger. More expensive but longer lasting.

Airjeep · 05-05-2016, 11:01 AM

If you have the same controller we do as installed by the dealer, does it has an "A" and "B" buttons?

One is used to scroll through the volts and amps, the other is to set the charge profile for flooded cell or AGM batteries. If it is set for AGM, it won't charge the wet battery properly. Check your settings.

Also, my experience is 80watts solar will not produce enough voltage/amps to recharge the batteries. Put on a 160w, now voltage goes over 14 vs maybe 13.2 with the 80w panel, amps 9+ vs 3-4.

Cheers, John

jmgunn1 · 05-05-2016, 01:00 PM

I was about to ask a similar question, I'm back in storage , been 11 days, went to pick up my rig only to find batteries to low to operate jack. Didn't have connected to shore power or a battery tender. I'm wondering what may have pulled them down? 2014 28 flying cloud. Original batteries

Your thoughts on battery tenders?

WindyJim · 05-05-2016, 01:07 PM

The furnace is the big draw and requires the batteries to be in good shape. I also believe the radio draws more also than one might think (certainly not on a par with the furnace, but significant).

In colder weather I still run my furnace at night, just set it lower than I would at home, say 60 degrees or a bit cooler. If you find that drains the batteries too much then you may have to lower it further so it cycles less frequently (also you have to close your overhead vents as the heated air goes right out the vents if open). Crack a window if you need to, just not the overhead vents when the furnace is being used.

WindyJim · 05-05-2016, 01:18 PM

When it came time to swap out my batteries, because they weren't holding up well, I bit the bullet and converted to 6-volt golf cart batteries. They have greater capacity and a longer life. The problem is they are a bit (not a lot) more expensive and the battery box has to be modified (not a simple job) to accommodate the taller 6-volt batteries.

I talked to Airstream about incorporating a change in their battery boxes that would allow them to still provide them with the two size 24 batteries, but be tall enough to also allow the use of 6-volt batteries. I talked to one of their technical people and asked him to pass it along as a possible design change for future battery boxes. I believe the battery boxes are outsourced and while they may have to "drop" down a couple inches to accommodate the Airstreams that have a front storage area, I told him I can't imagine they would cost Airstream more than maybe $10 more per box than they currently pay and they should have no problems recouping that on their selling prices of new Airstreams. He agreed and said he would pass the idea along.

KJRitchie · 05-05-2016, 01:23 PM

Apparently the 2016 models have a deeper battery box.

Kelvin

Al and Missy · 05-05-2016, 02:16 PM

Brawny,

The voltage of the batteries when under charge is not a good indicator of the state of charge. When charging, they should ideally read over 14 volts, at least at first. But if you have the original converter, they may not read over about 13.6. Leave the trailer connected to shore power overnight, then turn off everything and put the unit in STORE mode. Periodically measure the battery voltage. It should decline to about 12.6 and then stabilize. IF it continues to go down, either the batteries are bad or you have a parasitic load. I'm not familiar with the GoPower setup but some solar panels do not have an isolation diode and will discharge the battery when in the dark if the controller doesn't prevent it.

It sounds like you were connected to shore power for the weekend. If you were, the batteries should have been fully charged, assuming your USE/STORE switch was in the USE position.

If you were in USE and connected to shore power for the weekend, and only ran the furnace for a while, the batteries should not have been dead. If the furnace ran half the time for the 5 hours you said you were waiting on your wife, it should have taken less than 20 Amp hours. I don't know whether you have Group 24 or Group 27 batteries, but two of them should have well over 120, maybe 170 Amp-hours of capacity. It should have taken 60 or more Amp hours to drain your batteries. Either one or both of them are bad or your converter is not charging them properly.

Just my opinion....

Al

phann · 05-05-2016, 05:55 PM

You said you didnt pull the batteries to check the fluids, but Im unsure if you actually checked the fluids anyway. If the fluids are low, that would impair their performance and longevity.

BicenTw · 05-06-2016, 04:59 AM

Simply put, if you have a problem with the battery you chose as a replacement and you are away from the original purchase location you’ll want a nationwide resource to help. Walmart sell a variety of batteries both marine and auto and they are everywhere. You can always return their product for a replacement.

Cyclist · 05-06-2016, 05:49 AM

Brawny:

We bought our 2102 Airstream from Can-Am. When we picked it up in 2013 we had Andy install a 155 watt Go Power panel kit. After a summer and fall of travelling across Canada and down the west coast, we didn't have much faith in the Interstate batteries which didn't seem to hold a charge. We swapped them out for Lifeline AGM batteries (group 24) when in Los Angeles and haven't had a problem since. We have dry camped for as long as 10 days at a time including running the furnace overnight with no battery issues. The only caveat is that we need regular sunshine as we can't go more than two days before the batteries drop to 50% charge.

I think the 80 watt panel is too small to give a proper charge during daylight hours.

m.hony · 05-06-2016, 10:11 AM

I chose 2 Optima Blu Top AGM batteries.
I know that Trojan or Lifeline are maybe better quality batteries, but the Optima batteries are at a more affordable price point.
I have Optima Yellow Tops in a couple of vehicles with powerful aftermarket custom sound systems.
So far, so good.
I know Optima batteries aren't the same quality they once were. They sold out to Johnson Controls several years ago and production went to Mexico.

sgschwend · 05-06-2016, 09:43 PM

Calculating:
One 100 AH battery
50AH available,
Furnace while fan is on draws 8 amps, ( mine draws 5 amp)
Furnace runs 50% of the time, resulting in 4 AH useage per hour
16 hour night run time, resulting in 48 AH useage

Since 50 AH is available, your battery should last for over 16 hours of run time.
If your situation is different you can adjust the estimate above.