jwohlfeil
Orange, CA
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I am running 2 group 24 batteries on my Skyline Nomad 253 TT.
In order to run my 20 LCD flat panel TV when on battery power, I plug a Pure Sine inverter into the 12 volt plug inside the trailer, then plug the TV into the inverter.
The Problem:
The inverter has a low voltage alarm at 10.7 volts as most inverters do. Even when batteries are full and near full, the alarm sounds when I turn on the TV.
It seems like the TT electrical system (converter and main panel) is limiting the voltage to the 12 volt power plug, or somehow sucking up some of the power.
As a test, I connected the Pure Sine Inverter directly to the batteries up front, then plugged the TV into the inverter and it works fine.
Questions:
Can I get those missing volts back from the TT power system? Maybe upgrading the converter, or by flipping a switch or two on the main panel (to turn something off.)
Can I install a direct link to the batteries and bypass the converter? I would love to add an additional 12 volt outlet inside that connects directly to the battery. Or, connect an inverter directly to the battery and install another 110 power plug inside - pulling the "full power" directly off the batteries.
Any suggestions? Have you dealt with this?
As I'm sure we all do, I want to be able to run everything when DRY - accept the microwave and air conditioning. And currently, something is sucking up my 12 volt power -- help!
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tom_kat
way upstate new york/lake george area
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Joined: 02/28/2005
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sounds like the wireing going to the plug-in is to small to handle the load.replace the wireing going to the plug with larger wires or run new ones direct from the batterys or main power panel.
1985 Class A Holiday Rambler Imperial 33 +1979 Class C Holiday Rambler Statesman 1000 = 24 ft
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Casrep
On the road
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Joined: 01/07/2004
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I had the same problem. Wiring the inverter directly to the battery fixed it.
The voltage was "lost" at the 12V socket. Use the plug and see how HOT it gets supplying amps to the TV.
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BFL13
Victoria, BC
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Joined: 02/15/2006
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The 12v cigarette lighter style plug inside is limited to 8DC amps by its thin wire so your watts limit is about 96 (12 x 8) This is insufficient for your load. It is not the inverter.
Attaching the inverter to the battery is the correct solution. You can do it outside and plug the shore power into the inverter (first disconnect the converter to prevent back feed)or, what we do so not to have to go outside, is clamp the inverter to the battery lugs on the DC dist panel by the converter. This makes for an overly long wire run between the battery and the inverter, but it is "good enough" for the TV/DVD load we are doing it for.
Your two 24s are also low on amp hrs for normal camping which means your 12v voltage will get low sooner under a load. IMO replace those with two 6v for 232 amphr total. They have the same footprint as a 24 but are taller so check your battery location for space limits.
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Lightload
Spring Mills, PA
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Joined: 07/08/2008
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How about that! I've been dealing with the exact same problem! As a matter of fact, I was in the TT this morning with a volmeter to try to see what was going on. I had 14.1 volts at the battery (solar panel was charging)and 10 volts at the dc plug. Must be the normal way these things are wired, I guess.
What I have been doing is running the LCD TV off a size 24 AGM battery which I sit on the floor in front of the TV cabinet with the invertor clamps hooked directly on the battery terminals. No danger of spillage with the AGM battery but I was trying to get a "cleaner" looking setup by going with the plug inside the TV cabinet. Guess I'm looking at doing some rewiring.....
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2005 31' Prowler Bunk House TT (for the grandkids)
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smkettner
Southern California
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The wire is too long and too thin to the 12 volt connector to support the load at the proper voltage.
The wire from the battery to the distribution panel should be pretty good so you could connect there. Or connect to the battery direct. It is better to have a short fat 12 volt connection and a long 120 volt extension is fine.
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Clay L
Sioux Falls, South Dakota
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To calculate the proper wire size you can use a program I wrote.
It can be downloaded HERE.
Use the "Let program find the wire size" option.
Take the inverter watts and divide by by 12.6 to get the current. Use 12.4 or so for the voltage at the load. Enter the distance between the inverter and the battery.
The program will give you the right wire size.
Clay (WA5NMR), Lee,(Wife) Codi, Brandi (Shelties) and Damncat (damn cat)
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mike4947
N. Syracuse, NY
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I'll repeat what BFL13 said. Those plastic bodied 12 volt outlets are limited to a MAXIMUM of 8 amps. So adding large wire to it will only cause the outlet to be over loaded with anything over 8 amps (96 watts) and we've had way to many of them over the years melt down and char the surface they were mounted in.
Next best solution is the metal bodied outlet which is rate for a maximum of 20 amps (240 watts).
We recommend anything over 120 watts either be hard wired directly to the battery OR use a specialty high amperage 12 volt connection and suitable wire size.
Why inverter manufacturer's add the plug to 400 watt units is IMHO dangerous.
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Clay L
Sioux Falls, South Dakota
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mike4947 wrote:I'll repeat what BFL13 said. Those plastic bodied 12 volt outlets are limited to a MAXIMUM of 8 amps. So adding large wire to it will only cause the outlet to be over loaded with anything over 8 amps (96 watts) and we've had way to many of them over the years melt down and char the surface they were mounted in.
Next best solution is the metal bodied outlet which is rate for a maximum of 20 amps (240 watts).
We recommend anything over 120 watts either be hard wired directly to the battery OR use a specialty high amperage 12 volt connection and suitable wire size.
Why inverter manufacturer's add the plug to 400 watt units is IMHO dangerous.
Good catch.
I should have clarified that I was talking about new wire to the battery from the inverter and not advocating using the 12 volt outlet.
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janstey
Glenwood, IA
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Joined: 05/15/2003
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Why not just buy a 12v TV in the first place, eliminate the "middle man" of an inverter that also uses battery power to do "its" job. Then you can run the TV no matter what power is available.
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