need help on univolt converter

[72 Overlander 1]

I recently purchased a 72 Overlander at an auction. The unit has been very well kept, and everything seems to work on it, but the univolt converter is missing, and has been replaced with a small trickle charger, which cannot keep up with the battery drain when the interior lights, or furnace are on. I am new to the RV seen and know little to nothing on how the power distribution works on these things. The way I understand , from reading the owners manual, the lights, and other various items operate off of the battery, except when you have extenal power hooked up ie 115volt power cord, then the univolt takes over, and runs your interior lights, and charges your battery. Am I right so far? If so what can I buy at the local RV dealer to replace this univolt with and how many amp does it need to be to run my interior lights and furnace? Any help would be greatly appreciated.
Thank you

[overlander64]

Greetings 72 Overlander 1!

Welcome to the Forums and the world of Vintage Overlander ownership!

What you need to replace the Univolt is an RV power converter. You can source a new power converter at any one of a number of sources including on-line (such as Camping World, etc.), local RV service centers, or an Airstream dealer/repair center. The Univolt is Airstream's name for its power converter of choice for any given Vintage. When I purchased my '64 Overlander in 1995, I replaced its missing Univolt with a Magnatek power converter (30 AMP) from Camping World - - I later learned that a 50 or 60 AMP rated converter would have been preferred by most Airstreamers more familiar with the systems than I was at the time. When my Minuet needed a new power converter about 18-months ago, I had my local Airstream dealer replace it with the Univolt power converter being used in the current Airstreams.

Depending upon how the previous owner rigged the current 12-volt side of your power system, you may need a separate 12-volt fuse block for your revised installation.

Good luck with your Overlander!

Kevin

[davidz71]

Check out Camping World's Intellipower units with the optional Charge Wizzard. They have different size models available.

[wannabefulltime'n]

72 Overlander 1,

I purchased my 74 31’ Excella 500 last year and I am in the process of restoring. My univolt was working fine until the other day when it decided to go south on me. I researched the converter / univolt system and have found these interesting sites:

http://www.rversonline.org/ConfInvert.html

http://rversonline.org/ArtTipsConverter.html

http://bart.ccis.com/home/mnemeth/12volt/12volt.htm
Be sure to read the section titled .Converters vs. real battery chargers.

I am now considering purchasing one of the following Smart Chargers:

http://tools.reviewindex.com/reviews/B00009RB0T.html

http://shop.store.yahoo.com/onestops...se-2151ma.html

Hope this is of some help to you. I am also interested in any input from anyone else on the forum.

[wannabefulltime'n]

Stupid Question:

How do I view post to this forum that are older than “Last 24 hours” as that is the only other option I have found other than the 25 that come up automatically?

I posted to this thread yesterday and was hoping for some input on the “Charger vs. Converter” but I see it is not on the current list of post, therefore I assume it will go unanswered. I think this forum is great. It has been a great help in my restoration / upgrade project. Even though I haven’t participated much, I have been ease dropping on a regular basis over the past year.

[davidz71]

Check out http://bart.ccis.com/home/mnemeth/12volt/12volt.htm for a great primer on battery selection as well as how to charge them correctly. Also check out www.progressivedyn.com for the Inteli-power with charge wizzard. Make sure you check out the Battery Management 101 section of the Progressive Dynamics site for additional help. Andy at InlandRV also has a sale on Univolts this month according to his site.

[Safari Tim]

You can see how I replaced my univolt on my web site here.

I used a Statpower charger. Which has worked fine. But if I did it over I would probably go with the intelipower.

I had to build a new fuse holder since the original was in the univolt.

So fare it has worked out great the past couple of years.

[wannabefulltime'n]

Thanks for your input.

davidz71

I have reviewed the information @ http://bart.ccis.com/home/mnemeth/12volt/12volt.htm along with the other two links I mentioned in my first post to this thread. I am a Machinist, electrical work is not my specialty so I asked a friend at work who is an Electrician, working with AC & DC and he says’ the 12 volt Smart Charger would work fine, my question is, why do you need a power supply when you have the battery and can run solo from it when boondocking, it looks like you just need a Good Charging System to do the Job.

Safari Tim

Your installation is pretty much what I had in mind, except I will change the circuit panel over to the newer push in type of fuses used in the auto industry. Thanks for your input.

[davidz71]

The 12 v. battery system only goes so far when it is not being charged. Obviously, a 2 or 4 battery system can be wired to remain 12 volts but amperage is increased for longer usage. When boondocking, the 110 volt system is not available without an inverter so you are left with 12 volt DC power for the lights and the cigarette receptacles you should have in your trailer. The converter is not turned on because you are not hooked up to shorepower of 110 volts AC. Now we get to charging: You can charge through the umbelical cord from you tow vehicle; through a solar panel; through the 12 v. connection on a portable generator; through the 110 v. 15 amp/20 amp receptacles on the generator and lastly, through the converter connected to a generator. Those are your only options if 110 v. DC is not available.

Installing an Inverter can be as simple as plugging in a 400 watt Coleman, Vektor or other type into the cigarette receptacle of your trailer and plugging in a TV, DVD player, blender, etc. but you have to make sure that you have the correct size inverter for the equipment you are running. Four (4) six volt batteries are necessary to run a microwave and only for a brief time. A full bank of solar panels would be needed to work such a setup or the batteries would be quickly depleted.

[davidz71]

wannabe,
You are correct about not needing a power supply other than your fully charged battery when boondocking. I run a 5 watt solar panel and am wiring an additional 20 watt panel in for spring. I boondock for 3-5 days some weeks and have yet to have my 2 Delco Voyager 105 amp batteries even hint they were running low.

[wannabefulltime'n]

Thanks Craig,
Thats what I was thinking, and if you are connected to shorepower, then the "Smart Charger" will monitor and maintain your battery arragement. These chargers can be had for around $100. Also, the desulfication of the batteries will increase their life span two to three times if what I have read on the subject is correct.

[davidz71]

You've done your homework. I have heard of Delco Voyager sealed batteries lasting 10 years if they were maintained correctly, i.e. not overcharged where water is boiled out (can't replace the water), not undercharged or run down (best to not discharge much more than 50% and last, desulfate the plates properly. I read somewhere on the forum that an old trick used to be to smack the battery sides with the handle of a screwdriver to shake the plates loose but I'd rather use a charger with the correct mode to do this.

I like my BatteryMinder with it's slow 1 or 2 amp charge but for those in more of a hurry, they offer a 4 amp and 5 amp model. I probably would change to a Progressive Dynamics Inteli-power with Charge Wizzard if my current Magnetek every goes south and use the BatteryMinder on other vehicles every once in awhile to condition them.

[Stinky]

I am fairly sure my uni is dead but before I toss it I have a coupple questions.
1. Is there another fuse block in the univolt as well as the one outside? I am getting no power from the lugs that lead out but it is buzzing nicely.
2. If I find it is bad, it looks like all they have at Camping World is a 40 amp converter/charger and my uni is only 30 would this pose any problems?

[davidz71]

stinky,
The 40 amp shouldn't be a problem. I thought they also were carrying a 55 or 60 amp in the Inteli-power or were you referring to one of CW's other models?

[Stinky]

This is the one I saw http://www.campingworld.com/browse/s...m?skunum=17299

[Inland RV Center, In]

For another $20.00 you can get an Airstream univolt that puts out 55 amps.

A 40 amp converter would be considered light duty for 1969 and up coaches.

Andy

[Stinky]

Even if I only have a 30 amp AC service I can use a 55 amp univolt? I am totally new on this DC stuff.

[Inland RV Center, In]

Stinky.

30 amp city power service is 3600 watts.

40 amps at 12 volt DC is 480 watts, and 55 amps is 660 watts.

Don't confuse city power with 12 volts. They are two very different animals.

Andy

[wannabefulltime'n]

Andy,

What is the pros and cons of NOT using a converter, just using an automatic smart charger (automotive type) to maintain your deep cycle batteries?

[Inland RV Center, In]

The so called smart chargers, do not have an internal brain.

Therefore they don't know when to trickle charge or full charge.

A univolt has the brain, and keeps the battery or batteries topped off. When a load is applied, the univolt provides the current for that load, without depleting the battery charge.

If you have a 40 amp charger, the excess current must come from the battery.

Airstream concluded that a 55 amp charger was the most ideal to use. It is for that reason that Airstream has used the same univolt for several years.

Andy