Visit our Popular Forums

68 Overlander · 12-05-2006, 06:52 PM

Many of the old linear and ferroresonnant coverters were not voltage regulated so I wouldn't count on it. Watch your electrolyte like a hawk if you do.

Buttercup · 12-05-2006, 06:58 PM

Just my semi-professional opinion on the subject (as I have maintained batteries for a project but not professionally). Don't leave it plugged it in all the time. A better option might be to put the univolt on a timer. Set it to charge for perhaps 2 - 4 hours a day. That way you will not over charge or boil them out and you will keep the batteries topped off. OR just plug the Univolt in for one day each month. That will work but the timer option will actually be better for the batteries as it will go further in preventing sulfation.

Quote:

Originally Posted by cookeville34

Ok, I see your point about some of the 12V appliances, my experience was with our old Terry and a Starcraft popup, both used very little 12v for anything.
My Univolt is still working so I guess I'll just keep it.

When the trailer is sitting at the house, is it safe to leave it plugged up? Will the Univolt on my 79' automatically shut off when the battery is charged?

68 Overlander · 12-09-2006, 10:16 PM

Buttercup,
Without knowing the details of your project, I'd probably agree but it's really Okay to leave a modern switching converter hooked up with only a few conditions.
First, the battery must be healthy. With a shorted or weak cell the current might not taper off because the battery never reaches full charge voltage. With all converter/chargers in the automatic mode, the battery controls the output, not the converter/charger. I subscribe to quarterly specific gravity tests although I hate doing it because I seem to sacrifice a shirt every time. (My wife says I only want to mess with batteries when I'm wearing a good shirt for some reason)
Secondly, your climate plays an important part. Lead Acid batteries will gas at about 13.8 volts at 75 degrees. In Arizona, you will have to watch the water more vigilantly than in the northern climates. That is why I like 13.6 as a float and 13.2 that most of the 3-stage units are to cover all climates but leave them a little short of full charge.
With very few exceptions, manual override (If you have it) should not be used unless you know the true 'depth of discharge' before. Most battery indicators you find installed in RVs, including Airstream are only measuring voltage and not a good indicator of the true state of the battery.

Buttercup · 12-11-2006, 02:03 AM

Oh, sorry - I could have mentioned that. I have a car parked in a garage that is almost never used (a few times a year at best). I installed one of those "automatic" battery maintaining chargers. But as soon as it got the battery to 100% it would shut off and the battery would just die. So I dumped the automatic charger and got a standard battery charger, left it in manual on 10 amps and set it on a timer to run 2 hours on a day.

This setup does a few things:

maintains the battery charge
Doesn't overcharge/boil out the battery
10 amp charge goes further limiting the buildup of sulfation than a 1 amp charge would
helps circulate the juices

It's a poor mans solution to getting a 100 dollar charger. The thing with most of these "automatic chargers is that they do shut off the battery once fully charged, but most of them don't start charging when the battery voltage grops below a certain level.

Now the modern switching power supply chargers, like the Intellipower can do whatever they are programed to do. And because they are programed to equalize, float and charge a battery, they are the best choice for maintaining a battery that you can get.

Personally, I have no problem leaving the modern switching (solid state type) charger, supply like my Intellipower running all the time because it does put an equalizing charge on battery for a short period. That alone go a long way in keeping the battery happy. And because it only does it for a short period (mine for about 4 hours) the battery likely will not be boild dry provided simple inspections are done. I leave my trailer plugged in and all charged up all year long.

Quote:

Originally Posted by 68 Overlander

Buttercup,
Without knowing the details of your project, I'd probably agree but it's really Okay to leave a modern switching converter hooked up with only a few conditions.
First, the battery must be healthy. With a shorted or weak cell the current might not taper off because the battery never reaches full charge voltage. With all converter/chargers in the automatic mode, the battery controls the output, not the converter/charger. I subscribe to quarterly specific gravity tests although I hate doing it because I seem to sacrifice a shirt every time. (My wife says I only want to mess with batteries when I'm wearing a good shirt for some reason)
Secondly, your climate plays an important part. Lead Acid batteries will gas at about 13.8 volts at 75 degrees. In Arizona, you will have to watch the water more vigilantly than in the northern climates. That is why I like 13.6 as a float and 13.2 that most of the 3-stage units are to cover all climates but leave them a little short of full charge.
With very few exceptions, manual override (If you have it) should not be used unless you know the true 'depth of discharge' before. Most battery indicators you find installed in RVs, including Airstream are only measuring voltage and not a good indicator of the true state of the battery.

Kent · 01-04-2007, 07:38 PM

After reading the entry that i should get the biggest one they had, I ordered the 80 amp intelivolt. Any dangers in installing this? Note that most people in the forum are opting for the 65 amp model?

68 Overlander · 01-04-2007, 08:58 PM

Kent,
Welcome.
Yes there is some danger opting for the largest converter. Wiring to the battery needs to be able to handle the current. 80 amps is a bunch and I rarely recommend it in Airstreams.

**azflycaster** · 01-04-2007, 09:05 PM

Quote:

Originally Posted by Kent

After reading the entry that i should get the biggest one they had, I ordered the 80 amp intelivolt. Any dangers in installing this? Note that most people in the forum are opting for the 65 amp model?

Another draw back could be current draw if you attach a small generator to your trailer. A Honda EU1000 may not be able to supply enough current to the unit to meet it's demand. In that case it would go into overload and shut down.

68 Overlander · 01-04-2007, 09:19 PM

Richard is correct and I often get calls about the EU1000 not supplying enough power for the 60 Amp as well, even though on paper it should. Kent didin't mention anything about running a genny so don't want to get sidetracked but something to consider also, good point.

Lee Pace · 01-05-2007, 09:07 AM

Our rv dealership here tells us that the original Univolt almost never goes out. Ours is 35 years old and still going strong. I have also heard that about the Armstrong airconditioners, sure do see a lot of Colemans out there. I sure hope the dealer is right.

Lee Pace
72 Tradewind
WBCCI 7287
Greenville, Tx.