Voltage inverters

[Jim Creech]

Do any of you Wizards of Wattage have any real world experience with voltage inverters? I am considering installing installing on in the boat to run a small fridge that,according to the label plate draws 1.1 amps @ 115 vac. No reference to what the start-up surge is. As 115 v will be available I will no doubt take advantage of it and may want to run something else like a small fan or something. The more I read on line the more uncertain I am about necessary size and manufacturer. Naturally everyone claims theirs is the best and reviews are mixed.
As always,any advice, recommendations is appreciated!

PS: 12v dc to 115 vac.

[Dan Hintz]

I expect 5x surge currents for any steady-state current given...

[Pat Barry]

I know little, however, depending on the load that you will be running, you may need clean power (sine wave). A typical, low cost inverter is not sine wave output. They are noisy (electrically) and can cause issues with motors and certain other devices. Noise can extend into things like static heard on an AM radio for instance.

[Randy Viellenave]

All of the cheap ones have really bad efficiency. Look for a true sine wave unit with good efficiency, and that will server best. If you can squeeze a solar panel or windmill on there to help recharge that will extend the battery life too.

[Robert Delhommer Sr]

I have a small chest freezer in our rv that draws a little over 1 amp and a 300 watt PSW inverter will not start it up, blows the input fuse. So I use my 1,000 PSW inverter and it works beautifully.

[Ed Aumiller]

Robert is right on the size to use....
Problem you may think about... It will draw about 10amps when refrigerator is running...
Use a separate battery for it that you can charge off the alternator when engine is
running and the original battery is reserved for starting / running the engine...
Otherwise very easy to drain main battery and you will not be able to start engine..
... it is hard to get a jump start if not at a dock..

[Jim Creech]

Thank's guy's. I was thinking somewhere in the 1000-1200 watt range would be more than enough for my perceived needs. Both batteries gave out early this winter. I replaced the starting battery already so now I need to find a good deep cycle battery.

[Jason Roehl]

Robert is right on the size to use....
Problem you may think about... It will draw about 10amps when refrigerator is running...
Use a separate battery for it that you can charge off the alternator when engine is
running and the original battery is reserved for starting / running the engine...
Otherwise very easy to drain main battery and you will not be able to start engine..
... it is hard to get a jump start if not at a dock..

Good advice here--what you want to install is called an "isolator". This will let you run down the battery that powers the inverter without leaving you dead in the water without a battery for starting the engine.

A little Google searching will get you on the path to a good configuration.

[Shawn Pixley]

On ocean going boats, there are often two banks of batteries. I set up one bank as a start bank (single high crank battery). The other was set up for bait tank and other appliances (pair of deep cycle batteries wired in parallel). Certain functions were set up to run off either or were outside the bank switch (bilge, marine radio, GPS, and lights). There was no power generator on my boat.

It might be simpler to look for a 12 volt refrigerator depending upon how you charge the boat at dock.