battery / electrical help needed

[tinsltootsie]

After leaving my trailer to go home for a few days, I returned to find the power off. Turning on shore power kept popping the switch. Apparently the battery area had gotten wet from some heavy rain. I opened all compartments to dry things out, then was able to connect without the switch popping. After running my air for most of the day, I noticed the sufur smell. When I opened the battery compartment, which was warm, I saw some evidence of bubbling over near the battery. I left the compartment open and turned off the air conditioner. After several hours, the smell seems to have dissipated. I plan to baby it for a few days until my husband can get here to install a new battery. Is there anything I can do in the mean time? It is in a 74 airstream with the original univolt, and the battery is an interstate, about 2-3 years old. Any ideas??? Can I disconnect the battery and just run on shore power?? We have the trailer at the beach for another week.

[markdoane]

Carefully, with rubber gloves, soak the entire area with a solution of baking soda and water. Use lots of baking soda. Keep soaking the area until the baking soda stops bubbling.

After that, wipe down with detergent, then rinse with clear water.

[overlander63]

You probably already have this in your mind, but you'll probably need a new battery very soon. They don't take kindly to that kind of overcharging. While you're cleaning, you should think about cleaning the Univolt compartment out, and putting in a more modern converter. I put in a newer converter instead of trying to repair our Univolt, and am very happy with the results.

[tinsltootsie]

Originally Posted by markdoane

Carefully, with rubber gloves, soak the entire area with a solution of baking soda and water. Use lots of baking soda. Keep soaking the area until the baking soda stops bubbling.

After that, wipe down with detergent, then rinse with clear water.

That sounds like a good idea. It has stopped smelling, so I think it is not as hot. The battery door has been open since yesterday, and it stopped smelling about 6 hours after I turned the air conditioner off.

I do plan to replace the battery as soon as we can get one in, and have been thinking about replacing the univolt. I am glad to hear you are happy with your new converter. Our trailer is 33 years old, and everything but soft materials and flooring is original. But because the old stuff still worked, and worked well, I don't want to replace until needed. (the new is not always better adage) Thanks for your info.

[tinsltootsie]

What about leaving an old trailer hooked up to shore power? Any good way to do this which would increase the safety aspect? Can the battery be diconnected and the trailer just run off the electric?

[Ganglin]

This can be done. In our 71 a switch was installed by either Airstream or the dealer - it's in the bunk over the Univolt. When you turn it off and your plugged into shore power - only the 120 volt items still work. So you still have the fridge on, the A/C and all the 120 volt outlets.

I suspect this was done to quite the Univolt hum at night but it's really handy in our setup. When I'm at the trailer on a weekend the switch is on all the time (the hum of our Univolt is so low I barely hear it).During the week I shut it off - so no chance of the battery overcharging. But, the fridge stays cold all week.

[tinsltootsie]

Wo!! That sounds like the ticket! I want my fridge to stay cold, but don't want any battery/univolt problem.. it's enough to worry about the awnings and stuff. Anyone know how that is done??

[garry]

Leave the trailer plugged into CG power and you can disconnect the battery to keep it from overcharging. If you notice anything at all it will be the 12V lights might not be quite as bright. The univolt will continue to provide power to run the 12V things.
In the future you might want to put a disconnect switch at the battery to give you a easy way to prevent overcharging without having to pull the battery cable wire.
Running the AC has no effect on charging the battery since it is running from shore power only.

Garry

[azflycaster]

On my 75 TW one of the breakers goes to just the Univolt and the outside patio outlet. I turn that breaker off to quiet the unit at night and just run off the battery.

[tinsltootsie]

Originally Posted by garry

Leave the trailer plugged into CG power and you can disconnect the battery to keep it from overcharging. If you notice anything at all it will be the 12V lights might not be quite as bright. The univolt will continue to provide power to run the 12V things.
In the future you might want to put a disconnect switch at the battery to give you a easy way to prevent overcharging without having to pull the battery cable wire.
Running the AC has no effect on charging the battery since it is running from shore power only.

Garry

So I can disconnect the battery cables, and run just on shore power? We are going to look into putting a switch in later. I ran the air all afternoon and last night, and no problems. Even though you say it only runs off shore power, that was the only thing I saw that was different. Now i'm thinking the little bit of corrosion I see and the smell were because the battery compartment had gotten some water in in, which was probably creating some short. Is this a possibility?? all is dry now, but the little bit of corrosion is still in the compartment, none on the top.

My husband is coming tomorrow with a new battery.

[guy99]

Originally Posted by tinsltootsie

So I can disconnect the battery cables, and run just on shore power? ...

I'm not so sure about this, it is my understanding that the older univolts needed a battery in the circuit to serve as a filter.

I'd suggest that you call Randy at BestConverter - Inteli-Power, WFCO, Parallax, Inverters, Solar, Electrical Supplies, he is a member here and very helpful.

[sander17]

One nice thing about the modern solid state converters like the WFCO is that all the filtering is inside the converter, so no battery is needed to get nice smooth DC power.
Just don't buy another ferroresonant converter like the old Univolts. Yes, they still sell them!