testing the univolt

[flyingscot]

Forgive me if this question has been answered a thousand times, but, is there a simple way to test if the Univolt is charging my battery and if it is charging it correctly.
Thanks
Flying Scot

[Excella CM]

Yes, put a voltmeter across the battery and check the voltage. Should be between 13.5 & 14.5 volts approx. with the univolt on.

[Wabbiteer]

My recent Univolt experience is it keeps known good battery at 14.08 VDC after a week on float, no over heating or bubbling, with only occasional 12V loads applied... No humming, no buzzing - just power...

[Royce]

Originally Posted by Wabbiteer

My recent Univolt experience is it keeps known good battery at 14.08 VDC after a week on float, no over heating or bubbling, with only occasional 12V loads applied... No humming, no buzzing - just power...

Univolt, no hum, no buzz, What, is mine about to die? Buzz like crazy, won't be able to sleep in the coach with the blasted thing on. Would like to run this summer then replace next year. It does show between 13.5 and 14.5 volts across the battery, anytime I have checked it however. And the battery isn't losing any water.

[Wabbiteer]

This is second trailer; 1st Univolt rumbled at 60Hz until it didn't anymore and I can tell you cooked Univolt smells peppery. I can see the blue fuse panel and wiring buried under the bathtub in back of closet but I don't hear any noise.

Ripple voltage is bad thing on batteries (voids warranty on AGMs) and there are three largish capacitors inside the Univolt so I wonder if checking them might reduce vibration & noise, I gleefully discarded them when I recycled the fuse panel off AS1...

[flyingscot]

Excella CM, Thanks for the advice. Unfortunately, there was no increase in voltage across the battery with the Univolt on. I made sure the battery was Ok and able to take a charge. I checked all the fuses and breakers and they all checked out. Any ideas or is it time to go down the "replace the univolt" path.

[pamelake]

When I had my new univolt installed the dealer sent me home with a 'Charge Wizard' and told me to hook it up the inverter. I haven't done so yet. I really don't understand what it does, but I am wondering if it would answer this question.... Pam

[flyingscot]

Thanks everyone for the advice. Looks like I'll be going down the "How do you replace a Univolt" path

[Airstream 65]

Call Randy at 1-888-828-1893 BestConverter - Inteli-Power, WFCO, Parallax, Inverters, Solar, Electrical Supplies

He gives lots of good advice here on the forum, and his service is great.

[SLVRSRFR]

Maybe this can help you?

Just got a 1974 Sovereign and univolt is DOA. Very quiet though LOL. looks like I need to buy a new one. To hold me over till i can offord a new univolt I direct wired a battery charger to the fuse panel and set it to a 2 amp maintenance cycle. I have to use the 12volt dc very conservatively. When I require more juice I simply switch the charger to 10 or 50 amp. But it gets the job done and keeps the battery happy. The amazing thing is that for how many years the trailer sat; the battery charged right up... go figure...

[sander17]

Originally Posted by SLVRSRFR

Maybe this can help you?

When I require more juice I simply switch the charger to 10 or 50 amp. But it gets the job done and keeps the battery happy. The amazing thing is that for how many years the trailer sat; the battery charged right up... go figure...

For most inexpensive battery chargers, the 50 or 60 amp setting is for VERY short term use. It is meant to allow you to jump start your car with the charger. If you draw that much current for very long, it will get very hot and cook the charger.

Earlier a post mentioned the capacitors in the old univolts. They were to form a resonant circuit with the transformer, as these were known as ferroresonant converters. They were not filter capacitors, but they were the main cause of dead univolts. Replacing them can bring it back to life.

The best use for one of these is as a boat anchor. I replaced mine with a WFCO 3-stage converter and love the quiet power.

[SLVRSRFR]

thank you for your concern... you are correct the 50 amp setting is only a short time setting. The only setting I use ~continuosly~ is the 2amp. If i am going to use lots of pwer for a few min i switch over. But If I was not an electrician I would probobly blow my charger and battery up. ROFL! For anyone that may not know any better; Im glad you brought that up...

[overlander63]

Matt, your Univolt may still work. Check inside the mirrored medicine cabinet in your bathroom, you may find a black toggle switch. If it is "off", turn it on, and listen for the hum...If it hums, then check your battery voltage, with any luck, it will work.

[SLVRSRFR]

Sorry Overlander63; no switch (I may not have seen it or it may be located somwhere else in my trailer) But thanks for the tip. I would have never looked there for any components... BTW I have been reading this site for awhile and have found many of your posts helpful....