Battery Question

[FL Camper]

I am truly a newbie when it comes to the Airstream. We purchased our first one in December of 2014 and have been out twice. It is a 2015 27FB. I noticed that once we got it home and were getting it ready for the first outing, the battery was dead. Since I have a 30 AMP circuit at my home, i place the battery switch to the in use position and 24 hours later the battery seemed to be fine. I did find however, that the water levels in one of the batteries was really low....no problem added distilled water to the correct level. When we went on our second trip, I once again did not check for the batteries until we went to depart and checked the fridge to make sure it was on propane and low and behold.....all power to the coach was dead....no lights...nothing. (I am still trying to build a comprehensive pre departure checklist...lol) After camping for three days, I tried to test the battery again, and this time when I switched to battery power it showed 12.8 but quickly went to 12.4 and stabilized there.?? I returned to shore power for the remainder of the trip. Upon arriving home, I left my 30 AMP plug off for about 3 hours and then checked the battery again and this time it was 12.7 steady...water level low again. I am beginning to wonder if the original batteries might already be bad and if I should replace with to AGM batteries? If so, what AGM batteries have you all used. Any thoughts? I am pulling it back to to the dealer on Monday to have the full awning package installed.

[Al and Missy]

First, the behavior you described with the voltage declining from 12.8 to 12.4 is probably normal. A Flooded cell battery under charge will read a higher voltage than normal and take some time to decline to its normal reading. That said, I'd expect to see it decline to about 12.6.

Your dead batteries could be one of three things: your batteries, your converter/charger. or parasitic loads. On my trailer, even with the operate/store switch in store, the LPG (propane) detector was still powered up. The new ones don't draw as much current as mine, but guessing at 46 milliamps, a Group 27 battery would be discharged in about 3 months. I read on here that the standard converter/charger will overcharge the batteries and result in loss of water and ultimately capacity. If the battery has been allowed to deep discharge several times, it may be ruined.

Do you have AC power available when it is stored? If so, don't plug in your shore power cord but get a "battery maintainer". I use a CTEK on a car that is not driven much and it works well. Disconnect the negative terminal battery cable and connect the maintainer to the battery.

If AC power is not available, a lot of people, myself included, do one of two things, either disconnect the negative battery cable or pull the battery and bring it home where it can be monitored and maintained. I have done both. The last time I stored I just disconnected the battery and two months later it was still pretty well charged.

I replaced my stock converter. I used a PD 9260. Several on here have reported good results by contacting BestConverter.com. They will advise you on which will best fit your trailer.

In your situation I'd try disconnecting the battery during storage and see how that works. If it works, then just ensure you don't overcharge the batteries with the stock converter by not leaving the trailer plugged in for long durations. This is the Zero Dollar solution. All others cost money.

Al

[FL Camper]

Thanks Al, assuming I have AC power on the trailer 24/7 which I typically do, could I not just leave the battery switch in store thus stopping the charging process and then one day prior to departing put the switch back in use to make sure the battery is fully charged prior to leaving? I am just surprised that after just 6 weeks these batteries would be bad.

[Al and Missy]

On my trailer, putting the switch in store leaves the charger connected to the battery and disconnects them both from the input to the main fuse panel. So, in my case, no. I would have to unplug the shore power cable.

Try leaving the shore power connected for a couple of days. Then disconnect shore power and the battery negative cable and check the batteries every few days. If they hold a charge for several weeks, they may be OK. Your problem may be parasitic loads like the LPG detector. Make sure the refrigerator is off, its control panel always draws some 12V power, even when operating from shore power or propane. Make sure all the lights in the storage compartments are off.

If you have access to a multimeter, try this test:
1. Disconnect shore power
2. Set the multimeter on the low amps scale and put it between the battery negative post and the negative cable with the red lead connected to the cable and the black lead connected to the battery post. You should see very little, if any, current drain in the STORE mode.
3. If you have current drain, try to figure out where it is coming from. Unplug or disconnect the LPG detector. Most equipment in the trailer should be fed from the fuse panel and should be disconnected by the STORE switch.

Also, remember that your trailer may have sat at JC or at the dealer without charge being maintained on the batteries. This is not good for them. IF you have a local dealer, take it to them, as the batteries should be under warranty. Actually, you could just talk to them about the problem and have them troubleshoot it under warranty.

Al

[ROBERT CROSS]

I my experience if the batt's consistently need to be topped-up they are being overcharged.

Our OEM deep cycle Interstates were ruined on the dealers lot by keeping the trailer on shore power 24/7.

24/7 is not advisable without constant monitoring or up-grading to a 3 or 4 stage converter.

Contacting Best Converter is advisable.

Many here have done it

Good Luck

Bob

[KJRitchie]

Test your battery cells with a hydrometer. Even though my batteries read 12.8 fully charged 2 cells in one of the batteries had low specific gravity. Putting the battery on a charger and keeping the volts up around 15.5 to 16v for a few hours got the specific gravity up to normal on the affected cells. I still don't know if they are damaged and can hold up to a load. I'll find out when the AS comes out of storage for the winter.

I replaced my Parallax converter with a Progressive Dynamics PD4655 from Bestconverter.

Kelvin

[Rocinante]

Yep, we made the same replacement of a Parallax 7355 with a Progressive Dynamics 4655. We've been very pleased.

Meanwhile, it's entirely possible that while on the lot your battery was overcharged as has been noted, and/or ignored for some period of time while at low charge. Either or both actions can damage your batteries.

We were unhappy with our battery capacity and after checking specific gravity values for them we were able to convince our dealer to run a capacity test in addition to the usual load test. Our batteries passed the load test, but were a bit marginal on the capacity check. So, as a "customer service" move the dealer agreed to replace our batteries even though they weren't entirely convinced of the problem. We're very pleased they did this for us and as a result, we have lots of good things to say about them.

[SilverBuddha]

Fl Camper,

If your Airstream has stock Interstate batteries, you can take them to any Interstate battery dealer ( Panama City, FL has several) and they will perform a load test. There is a date code (label) affixed to the battery case which identifies the manufacturer date.
I had issues with both of my Interstate batteries and the local (Interstate) dealer replaced them and reset the warranty date.
This might offer you more time to research the battery charger options.

Cheers