How do you check an inverter to see if it is putting out the proper DC voltage? My lights in my Tioga worked when I lived in Oregon then when I drove it back to Texas they quit working.......any ideas or insight on what and how to check?


Tioga Sportsman

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  A TRANSFORMER is for changing AC voltage up or down like 120 to 12 or 12 to 120 BUTTTTT that's ONLY AC to AC. Other then incandescent lights, many typical RV 12 VDC Appliances (especially if electronic) need 12 volts DC NOT 12 volts AC.

 A Converter/Charger converts 120 VAC to 12 VDC and YES can be used to power 12 volt DC appliances and lights etc.

 With no house batteries YES when plugged into 120 VAC shore power the Converter/Charger will allow the use of 12 volt DC loads and if unplugged (with no battery) none of that will work. HOWEVER a 120 VAC to 12 VAC TRANSFORMER is NOT what I recommend since it ONLY supplies AC voltage while many typical RV loads require DC. A phone charger or LED lights and small electronics are designed for 12 volts DC but NOT AC.

 John T 

has anyone heard of or used PowerMax converters?

is this a good converter?

Look at the attached jpeg. looking at the schematic, how do you determine the amp size of a converter?


The Powermax unit you asked about is available in 35, 45, 55, 75, 100, 120 Amps.

 It appears to be more like a fixed (albeit adjustable) DC output Converter and NOT any 3 or 4 stage progressive "Smart Charger", HOWEVER if you aren't using batteries anyway that's NOT an issue.

 No idea of the rating of you old unit based soley on the picture, I could take an educated guess but not going to

John T

My '84 came with a 30-amp (if memory serves) converter. It was the old "battery boiler" style converter and it could not keep up under the load of interior lights even after replacing the house batteries.

I went with a 55-amp PowerMax unit and it's been great. I keep it plugged in 24x7 and the batteries are holding up fine after almost 2 years. It puts out plenty of amperage for the house needs (water pump when required, battery charging, lighting, etc.). I got a little more amperage than stock in the hopes of installing a 12V a/v system (haven't done that yet).

You won't be disappointed with the PowerMax. Easy installation too.

That is all I wanted was an easy answer! No definitions or drawn out answers, all I want to do is run my interior lights, fart fan and stove fan. No battery charging will be involved....Thank You Jim Stoltz!!

The converter keeps your house battery(ies) charged, maybe your chassis (truck) battery too depending on your configuration. I have not tried to use the PowerMax without my house batteries in the loop. I know for a fact that the old style converter that I replaced required batteries to be in the circuit.

Haven't had batteries the past 4 years.

If there is a power converter without a battery charger that would be great!

  You state "That is all I wanted was an easy answer! No definitions or drawn out answers"

 LOL  all the fine gentlemen here are only trying to help, and I for one appreciate what they do. Its hard to get the exact answers a person wants at times I guess. But hey I'm sure they including myself keep trying our best.

 Best wishes and Merry Christmas

 John T

Hi Tioga sportsman, I had a situation a month or so ago that I still don't fully grasp but the long and short of it is this. My RV was plugged into my 30 amp RV outlet and every thing worked. I moved it down to my house to prep it for a Thanksgiving camp and had it plugged into my garage with an adapter to a 20 amp. outlet. I won't go into detail but, what is interesting is the scenario. I had an RV that worked in all respect at my pole barn but when I brought it to the house it did not. My problem led me to remove my battery and put it on my farm charger. With the battery out and the RV plugged into my garage outlet nothing DC worked. After doing some research on the net I was made aware of the fact that I should have DC voltage; with or with out the battery. So, I was in the market for a new converter.  I decided to take the camper back to the barn and finish getting it ready for the new converter up there because I have better lighting. For some reason ( I cant remember why) I plugged it back into the RV outlet and to my surprise I noticed that the lights was back on in the coach. I have no clue why it would not work at the garage but does at the poll barn except for it running off a regular house hold extension cord at the garage and maybe causing a low voltage situation. At any rate we went on our camp out and back home and to this day It is still working perfectly. I guess what I am saying  is check other power sources before you condemn it. On a further note, I checked my garage for low voltage and found nothing out of tilt.  Hope this is of some help to you.  

The "Final" resting place of my RV is now my home behind my home. Everything worked fine up until now. I know how to use a voltmeter and have checked everything except for pulling the converter and checking if there is a reset, internal fuse blown, the power supply output or the output of the converter. I really don't want get into that cramped space to do that but might as well just to be sure. It seems a lot simpler from all the reviews I have read just to add the new power max converter.




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