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CORockies · 05-30-2016, 11:28 PM

Long story short we had the original batteries replaced. They were found to be bad. New batteries installed by the dealer under warranty. First night out boondocking and no problems. Then the Airstream sat in storage for two weeks. Went to hook up and the batteries are dead. Jack post wouldn't even go up. Take off to go camping. The screen in the Airstream says the batteries are at 12.4 volts. Run the furnance all night at 55 degrees. The furnance quits working because the voltage dropped all the way down to 9 volts. What gives? Is there a parasitic loss going on that we can't figure out? Or, could it be something else? Thanks.

Zane and Diane

J. Morgan · 05-30-2016, 11:35 PM

There is a draw that pulled your batteries was down in storage, and unless you hooked up to shore power for a few or several hours after retrieving the trailer from storage, you will not have gotten a full charge as indicated by only having 12.4 volts.

That is not a full charge, and the furnace is a big electric user too which did not help matters at all. (Your tow vehicle will charge your batteries, but slowly and not as well as your onboard charger)

You need several hours on shore power or a generator to try and see if the batteries will take a full charge after that huge discharge.

It is my understanding that there is a switch that you need to turn to STORE when the trailer is parked for more than a day to stay parasitic discharge.

Superat stultitia.

Wayne&Sam · 05-31-2016, 04:56 AM

Quote:

Originally Posted by J. Morgan

It is my understanding that there is a switch that you need to turn to STORE when the trailer is parked for more than a day to stay parasitic discharge.

Even in "Store" the LP leak detector draws a little and will run the batteries down.

lsbrodsky · 05-31-2016, 05:16 AM

A little more advice. Once you completely discharge your batteries, they will never be the same again. You can get them charged, but not fully charged. Only use the voltage as an indication of charge if there is no charging source connected, not the TV, not the charger, no solar. In storage the switch needs to be in STORE, but as stated above, the LP gas detector will still kill your batteries.
You could never run the furnace all night and still have enough charge in the batteries. Use blankets and turn the furnace on when you get up.
You do not say whether you have solar, but without it, you really will need a generator to boondock; you do not have enough battery capacity otherwise. If you connect to shorepower most often, read the many posts about replacing the converter/charger.
Larry

overlander63 · 05-31-2016, 05:33 AM

Complete discharge of the batteries will reduce their capacity by around 2% or so per discharge/recharge cycle. Obviously, it won't take many of those cycles to reduce capacity to the point the batteries won't be usable for their intended purpose. In the future, try no to discharge them by much more than 50%, they will last much longer.

CORockies · 05-31-2016, 08:54 AM

Thanks for all of the advice. Sounds like the LP detector may be the culprit while in storage. Anyway around this one short of disconnecting the batteries? We definitely make sure that the switch has been put into store mode. Solar will be down the road as it will be needed for what we like to do. Again, thanks for the advice!

Zane and Diane

lsbrodsky · 05-31-2016, 09:06 AM

Nope. Disconnect the batteries or provide some charging. With solar and outside storage you never have to worry about it.
Larry

Al and Missy · 05-31-2016, 11:15 AM

Quote:

Originally Posted by Wayne&Sam

Even in "Store" the LP leak detector draws a little and will run the batteries down.

12.4 volts is about 70% capacity for a lead acid battery bank. If you know how many of what type batteries you have you can approximate the load you are looking for. Assuming you have two Group 27 batteries (105 Amp-hours each), that would mean about 200mA of current drain over two weeks. The LP detector in my 2001 and 2002 trailers drew 70mA, so it is probable you have something else draining the batteries.

I routinely store my trailer for several weeks without the batteries being dead. Until I rewired the detector in my 25 I would disconnect the negative cable at the (single) Group 27 battery on the tongue. On my 30 (with two Group 27s) I just throw the STORE/USE switch which should eliminate most loads. If you are "handy" you could re-wire your propane detector to the other side of the STORE/USE switch and eliminate that load but I don't think that is your problem. My 25 had a switch mounted adjacent to the detector to turn off the power to it, but that then requires that you remember to turn it on when using the trailer. I decided to rewire the detector at the STORE/USE switch. I have not done that to my 30 yet.

The OEM converter will take hours (maybe more than 24) to charge your battery(ies). Your tow vehicle will not provide enough charge in a day's drive either. If you boondock with no shore power you need to hook up the trailer to power prior to going into storage. A properly sized smart, three or four stage converter will give you a 90% charge in a few hours and a full charge in less than a day.

The only way to tell the charge level of batteries by voltage is to charge them and then let them rest (no charge or discharge happening) for several hours. You would then like to see 12.6 volts for a full charge. An alternative (but messy and potentially hazardous) is to get a hydrometer at an auto parts place and measure the specific gravity. The problem is that once you do that, the hydrometer has some residual battery acid in it and you have to rinse it well and dry it before storage or throw it away and get another the next time (they're only a few dollars).

Al

Boogieshoes · 05-31-2016, 12:37 PM

our new Classic went into storage Apr 8th; 6 weeks later when I hooked it up to move to a new storage unit, the batteries were completely dead. Especially concerning given it was plugged into shore power the entire time. Have been away since and will not be back to check until next week. We have factory solar; while that is obviously no use indoors, it does mean we have the upgraded batteries.

guskmg · 05-31-2016, 03:56 PM

No matter how you cut it (pun intended), the battery should have a manual master disconnect. Even if you want to keep the batteries charged with solar outside. Some of the solar systems
have a residual drain when connected to the batteries. When you go to covered storage you can isolate the batteries from known or unintended residual drain. AGM batteries will go for months in isolated storage before it reaches 40-50% charge. Now, the Airstream Factory must wire the switch the way they come because of state/national codes in effect when the product is shipped. That means if you need better isolation you must do it yourself. It is technically illegal for a technician to make the modification(s). I have done this for years and even with submarginal electrical systems I usually got 6-7 years out of AGMs.
guskmg

Drathaar · 05-31-2016, 05:07 PM

Anytime we have the Airstream in covered storage and not connected to shore power, the batteries are disconnected, or I go down every week or so and charge the batteries.

In addition to the LP detector, I'm told the stereo bass unit is an additional drain. Not sure if that's true, but... maybe.

Mark Wiltrakis · 05-31-2016, 05:39 PM

I replaced my two Lifeline AGM's today and added a battery disconnect switch. It disconnects the positive side of the batteries from my 12 volt fuse panel. Lifeline says "Disconnect the negative battery cable" for storing more than a month. Is there any reason my installation on the positive half of the circuit is less desirable?

J. Morgan · 05-31-2016, 06:01 PM

Not really IMO, except that it is safer to disconnect the negative terminal, and even more so with more than one battery.

Superat stultitia.

Silver Hawk · 05-31-2016, 06:29 PM

Negative is the 'ground' side of the battery. Positive is it 'out' side of the battery for the amperage going to the panel. Disconnecting the ground you do not get much of a spark. Disconnecting the positive you get full amperage of the battery. Large spark. Will burn out switch contacts and is dangerous and if there are any fumes - will cause an explosion.

Mark Wiltrakis · 05-31-2016, 07:46 PM

I got no spark with a half-dozen on/off switchings today. Hoping for continued similar performance. The switch (made by Marinco) is rated for 275 continuous amps and 475 intermittent amps.

Ronman · 05-31-2016, 09:01 PM

I have a Noco G26000 smart charger. I always charge 100% before and after the trip. I also use it with my Honda 2000 when dry camping. Works pretty well.

Al and Missy · 06-01-2016, 12:09 AM

Quote:

Originally Posted by Silver Hawk

Negative is the 'ground' side of the battery. Positive is it 'out' side of the battery for the amperage going to the panel. Disconnecting the ground you do not get much of a spark. Disconnecting the positive you get full amperage of the battery. Large spark. Will burn out switch contacts and is dangerous and if there are any fumes - will cause an explosion.

Whatever current goes out of the positive terminal goes into the negative side. There is no difference in current except for direction through the switch.

The safety issue is that when wrenching on the positive terminal, if you slip and the wrench hits the body you have essentially shorted the battery, resulting in a big spark and the potential for a fire or battery explosion. When wrenching on the negative terminal which is connected to the body, if you slip the only thing you can hit that is a problem is the positive terminal. When disconnecting the battery, negative terminal first. When connecting the battery, negative terminal last.

Al

PJohnson · 06-02-2016, 04:03 PM

The new classics have 2 parasitic drains. The LP gas detector and the Inverter. The LP detector draws 60 milliamperes and the Inverter draw 105 milliamperes. Both are connected directly to the battery. If you use "STORE" the converter will be isolated from the battery and the battery will not be charged while the 165 milliamperes drain will remain. 0.165 amp hours X 24 Hours X 7 days is approximately 28 amp hours per week. If you have 200 amp hours of storage your batteries will lose 14% per week. Therefore you will need to recharge your batteries every 3 weeks.

Jammer · 06-02-2016, 04:25 PM

Quote:

Originally Posted by CORockies

Thanks for all of the advice. Sounds like the LP detector may be the culprit while in storage. Anyway around this one short of disconnecting the batteries? We definitely make sure that the switch has been put into store mode. Solar will be down the road as it will be needed for what we like to do. Again, thanks for the advice!

Zane and Diane

On my trailer, I disconnected the LP detector and threw it in the trash. Problem solved.

I do not believe they provide any safety benefit in RVs. They do help in yachts, which for various reasons are at much greater risk of an undetected leak.

KJRitchie · 06-02-2016, 04:33 PM

Move the LP leak detector 12v connection to the use/store switch. When the use store switch is in store the LP detector is off unless you are connected to shore power.

While is storage just disconnect the negative battery terminal or if you want to do what every SOB does nowadays, install a mechanical disconnect switch.

Kelvin