inverters

[Deano2002]

I have a 9 cubic foot residential fridge that draws 90 watts, what size inverter would I need to run that while going down the highway? I would like to not run the generator if I do not have to

 

[Isaac-1]

This is a hard one to answer as it may draw 90 watts while running, and draw considerably more when considering inrush current as the compressor starts.  Also many of the cheaper import inverters on the market are overly optimistic in their ratings, sometimes ludicrously so.

Having said that I suspect you would be ok with an inverter with a 250-300 watt rating from a reputable manufacturer if it were connected to the battery bank with a large enough cable.

If I had to pick something on a budget looking at what is available on Amazon under $100, it would likely be this one as it comes from a brand name company in the inverter world https://smile.amazon.com/Victron-Power-Inverter-Phoenix-350VA/dp/B01EW5ZA94

 

[John From Detroit]

500-1000 should do it. No guarantee on the 500. Unit takes 5-10 times running to start.

 

[Gary RV_Wizard]

Many modern fridges have a very soft start, so the inrush current isn't too bad. I would think 500-600W inverter would be sufficient, but these days a 1000W isn't much more expensive and you can probably get one with an auto-transfer switch to handle the changeover. Get a pure sine inverter, not MSW (modified sine).

Something like these:  https://www.amazon.com/Power-Inverter-Automatic-Transfer-Switch/dp/B00TI1D5JKhttps://www.donrowe.com/cooper-bussmann-12-110-1000-pure-sine-inverter-p/cb1000.htm

Magnum makes a nice little 600W inverter with auro transfer, but the price is steep.
https://www.amazon.com/Magnum-Inverter-transfer-Switch-Modified/dp/B00B6WC3II

 

[Isaac-1]

The Victron inverter I mentioned above claims to have a 700 watt surge load capability see https://www.victronenergy.com/upload/documents/Datasheet-Phoenix-Inverter-180VA-1200VA-EN.pdf

 

[John From Detroit]

I have a 2,000 that was under 800 bucks I just hooked up... SO you know the cost of inverters. 775+_ tax and I later found it for 555+ shipping and tax (I did not pay shipping. A lot of the companies that are very cheap plus shipping gouge you on teh shipping.. the 775 was common among many places including Camping World)  Xantrex Freedom 2000XC

I was not happy with the 120 volt connections. they won't take 10ga  I'll modify later.

 

[Deano2002]

I do have a 300 watt inverter behind the breaker panel but never knew what is was for and if it works. I will take a pic later.

 

[Deano2002]

I have a 2,000 that was under 800 bucks I just hooked up... SO you know the cost of inverters. 775+_ tax and I later found it for 555+ shipping and tax (I did not pay shipping. A lot of the companies that are very cheap plus shipping gouge you on teh shipping.. the 775 was common among many places including Camping World)  Xantrex Freedom 2000XC

I was not happy with the 120 volt connections. they won't take 10ga  I'll modify later.

ouch, maybe I will run the genset off and on. Do I have to have a transfer switch or can I plug it in manually?

 

[Alfa38User]

I do have a 300 watt inverter behind the breaker panel but never knew what is was for and if it works. I will take a pic later.

It was likely for the entertainment centre (TV etc).... Disconnecting it will likely cause the TV to fail unless you have it plugged into another outlet that is not hidden behind the TV.

 

[Gary RV_Wizard]

ouch, maybe I will run the genset off and on. Do I have to have a transfer switch or can I plug it in manually?

The unit John cited is a powerful inverter/converter/charger with auto transfer, probably way overkill if the only thing you want to do is run the fridge while driving.  You can add a simple 1000W inverter with no transfer switch for well under $200 (I provided links to a couple of examples).  The AIMS unit even includes a transfer switch for its $170 price.

No, you do not need an auto transfer switch - it's just a convenience that also avoids forgetting to make the changeover when you arrive at the campsite of or being driving.  Further, the fridge cord is usually not easily accessible to just plug elsewhere.  Once you think through all the logistics, the auto-transfer switch usually sounds like a worthwhile extra.

You can add a transfer switch to an inverter for about $70. Here's one such add-on:https://www.amazon.com/Xantrex-8080915-PROwatt-Transfer-Switch/dp/B004S5Y158/

 

[John From Detroit]

Ah but when I was having power issues yesterday (Fixed I might add.. New dogbone) that Freedom 2000XC made sure the computer did not re-start. the things that need 120v Full time had it. Through several adapter failures.  The new adapter ---- Does not fail  (At least not this year).  The old one was at least 13 years old. possibly older.