What are the symptoms of a bad Univolt?

[BREWHEAD]

I have a 1979 Excella and I wanted to know what are the symptoms of a bad univolt? I think my univolt charger has kicked the dust which might of been spurred on by a power surge at a campground.

Any help would be great.

THANKS

[Scott J-24]

Based on what I have read on the forum, the first symptom of a bad UniVolt is that it is still installed in your Airstream.

[SteveH]

Jokeing aside, usually the first symtoms are no 12 volts after the battery runs down.

[Inland RV Center, In]

Or, it cooks the battery.

Andy

[Nuvite-F]

Measure your 12 V bus voltage with the trailer connected to ground power and disconnected from the tow vehicle. Should be somewhere in the neighborhood of 13 volts. If it's 12.5 or so the battery probably isn't charging; let some lights run for a while and see if it drops. Conversely, the old boat anchor convertors were notorious for overcharging the batteries; if you are seeing 14-15 volts that's too high. (Note: the current generation microprocessor controlled convertors give the batteries a shot of 14-15 volts now and then, but only briefly; a steady 14+ volts is too high.)

Our 1980 model has a DC voltmeter on the systems monitor panel--maybe yours does too?
.

[eubank]

Originally Posted by Inland RV Center, In

Or, it cooks the battery.
Andy

Hear, hear! That's exactly what a bad converter did to a battery in our rig. We kept on smelling something funny, almost like sewer gas, or so we thought. It was a boiling battery.

Lynn

[SteveH]

Sometimes those "cooking the battery" events begin with a bad battery. I had one where one of the battery developed a shorted cell. The converter, an Intellipower I might add, kept pumping 13.8 volts to the batteries trying to bring up the bad one until the battery actually blew up.

After I replaced the batteries, all was well.

The original Univolts are not smart in any way, so they would be even worse.

[idroba]

Originally Posted by Scott J-24

Based on what I have read on the forum, the first symptom of a bad UniVolt is that it is still installed in your Airstream.

Yes, they are technologically obsolete by virtually all standards of electrical systems available today. Good in their time, but that is time is long gone.

[Skater]

The original converter in the B190 was down to about 10 volts output when I replaced it. That was a pretty good sign, too.

The original converter in the trailer wasn't doing well, either - it wasn't able to keep up the voltage even when we had just a few lights on.

[Lumatic]

In these parts we say the only good univolt is a dead univolt Pardner!

[darryl97420]

So that I may gain some insight from this thread...Disconnect the battery and check the output voltage to the battery leads? If its 13.0vdc its ok? What about when lights are turned on? I turned on every one I could find and the voltage dipped to 12.0vdc. Can I consider my Univolt to be in decent working condition?

I hope it isn't considered hijacking a thread when your looking for additional insight.

[Inland RV Center, In]

Originally Posted by darryl97420

So that I may gain some insight from this thread...Disconnect the battery and check the output voltage to the battery leads? If its 13.0vdc its ok? What about when lights are turned on? I turned on every one I could find and the voltage dipped to 12.0vdc. Can I consider my Univolt to be in decent working condition?

I hope it isn't considered hijacking a thread when your looking for additional insight.

The output voltage of a "Univolt" cannot be checked unless it's hook up to a battery or a large condenser (capacitor).

The output will measure very low, like 9 to 10 volts, unless that load is attached.

That would give a false indication of a bad Univolt.

Andy

[darryl97420]

There is where my problem is. I tested the output without a load and it showed 13.0 vdc. Hum...

A new battery is going in later this week. Once installed I will retest the voltage.

Thank you Andy for your help.