Hi all,Been doing a lot of searching and reading about inverters on the forums. My old toy hauler I installed an xantrex 1000w inverter and it worked fine however died once and seems pretty taxing on the batteries. Im in a class A now and need an inverter. I've been reading on the boards that xantrex is no longer the front runner and I am pretty sure I've settled on getting a go power inverter. My question is this... How large? I want to be able to run 3 LCD TV's (DVD is already 12v) and charge cell phone and laptop. I'm thinking 1000w is overkill for this. Think 300w would do? 600w? I'm never going to use the coffeemaker/micro/ac on battery. Just TV and charge. Any thoughts?

Yes, been there done that, 3-400 watts will do fine.

3x LCD + 1 laptop might get you over 300w if all used at the same time.Read the labels that show wattage or get a Kill-A-Watt meter to verify what they draw.I assume the Tvs will draw less than the label unless you are also at max volume.600w should be no trouble.

3 LCDs at the same time? If so, a 600W will work. If two or less, 300W is plenty.

There is little difference if any between 1000w inverter and a 400w inverter for draw while running TVs etc. (you do see a diff if you do it with a 2000w though) It is all about inverter efficiency curves which are best at say 3/4 the wattage. So if your load is going to be 150w you want a 200w inverter. But if you use a 1000w inverter it's nearly the same AH out of the batteries.The difference is the wiring and fusing for the inverter based on what the inverter could do. But you can wire it up only for what you will do with it, so if you are certain of the max load, then you could use the same wiring for the 1000 as for the 400.I only needed a 400, but some 1000s came up on sale and I grabbed one. I only use it as though it were a 300, but I do have a nice back-up for the 2000w for running up to 100a loads like the kettle or toaster. Still need the 2000 as it is the only one that will run the microwave.So the lesson is, you don't lose any AH by running the 1000w instead of a 400w for the TV/DVD but you gain some redundancy for running the kettle and toaster.

BFL13 wrote:There is little difference if any between 1000w inverter and a 400w inverter for draw while running TVs etc. (you do see a diff if you do it with a 2000w though) It is all about inverter efficiency curves which are best at say 3/4 the wattage. So if your load is going to be 150w you want a 200w inverter. But if you use a 1000w inverter it's nearly the same AH out of the batteries.The difference is the wiring and fusing for the inverter based on what the inverter could do. But you can wire it up only for what you will do with it, so if you are certain of the max load, then you could use the same wiring for the 1000 as for the 400.I only needed a 400, but some 1000s came up on sale and I grabbed one. I only use it as though it were a 300, but I do have a nice back-up for the 2000w for running up to 100a loads like the kettle or toaster. Still need the 2000 as it is the only one that will run the microwave.So the lesson is, you don't lose any AH by running the 1000w instead of a 400w for the TV/DVD but you gain some redundancy for running the kettle and toaster.I whole heartedly agree with BFL. I went what I thought was "overboard" got a good deal on a 1000W Xantrex PSW inverter for TV etc. Pretty soon DW said "will it run the hairdryer" one of those travel ones. Yup, but a 400W wouldn't. How about the toaster?? Yup. And finally after her commenting that the micowave would be nice at lunchstops at rest areas, I put in a $100 panasonic "inverter" microwave that will run just fine on 1000W if you set the power level to 50%. And at 50% power, it only adds about 25% or so to the time it takes to warm stuff up. And we can run the microwave when dry camped without going out and firing up the generator. so, after two years, the 1000W isn't "overboard" it's "adequate" and had I done a 400 or 600 W I'd have decided it was "almost adquate" not to be confused with "barely adequate".BTW I've been very happy with the Xantrex.

inverter sizing | Good Sam Community

15 Replies

pianotuna
Nomad III
Dec 02, 2013
Hi,

Put a switch on the converter. The plug on the power center is flimsy. DAMHIK

jeremywatco wrote:

1. Unplug converter (plugs into back of power center, no breaker for it)

Only downside I see, is when its time to charge the batteries I need to go back outside and switch the cable again. Hope its not raining!
mena661
Explorer
Dec 02, 2013
That's it Jeremy!!
jeremywatco
Explorer
Dec 01, 2013
pianotuna wrote:
Hi,

Mount the inverter as close as is humanly possible to the battery bank. Run the romex and put a female 30 amp (or 50 amp) outlet on it. Then just plug in the shore power cord after turning the converter off.

I like this idea. When I did the install in my old toy hauler I put in a separate sub-panel with transfer switches... was a pain in the rear.

I guess now the steps would be..

1. Unplug converter (plugs into back of power center, no breaker for it)
2. Shutoff A/C, Microwave Breakers (Protect against kids & wife).
3. Switch Fridge to Gas
4. Go outside and move Shore Power from Generator to Inverter.

Only downside I see, is when its time to charge the batteries I need to go back outside and switch the cable again. Hope its not raining!
mena661
Explorer
Dec 01, 2013
Jeremy, if your rig is like mine there's metal under your compartments carpet.
pianotuna
Nomad III
Dec 01, 2013
Hi,

Mount the inverter as close as is humanly possible to the battery bank. Run the romex and put a female 30 amp (or 50 amp) outlet on it. Then just plug in the shore power cord after turning the converter off.
jeremywatco
Explorer
Dec 01, 2013
Thanks everyone for the info! I'm going to keep my eye's out for a good deal (ebay, etc) on a Go Power or Xantrex 600w.

Only other question I have is where to put this sucker. My '14 Fleetwood Storm has the batteries under the top coach step and there is zero room in there.

I was thinking of mounting it in the storage compartment directly next to this door which has a passthrough area to the other side of the coach and isnt a sealed bin (where the fresh water tank is sitting). And then running romex to the back of the coach where the breakers are.... Main issue I have is I can't tell what type of material I'd be screwing into and from under the coach I can't tell whats directly under this area. I attached a picture below.

Other idea I had was the mount it under the bed in the bedroom but that is 12 feet from the batteries and I know that when in use the fan can be noisy on these things.
ewarnerusa
Nomad
Dec 01, 2013
I suggest the highest power capacity one you can fit/afford. You're not saving enough power to be justified by using a smaller capacity inverter for smaller power needs, in my opinion.
pianotuna
Nomad III
Dec 01, 2013
Hi,

Rule of thumb for sizing is 125% of the maximum load that will be powered. So 300 watts needs a 380 watt inverter.

I'd go for the 1000 watt myself. The prowatt is pretty darn cheap for a psw. Look for pricing at bestconverters.com
mena661
Explorer
Dec 01, 2013
The Go Power PSW 300W units work very well. They weigh more than the Xantrex PSW 600W units. Both smk and myself have one.
KD4UPL
Explorer
Dec 01, 2013
I don't know much about GoPower but Xantrex is still a very high quality inverter. They make huge inverters for houses; I've installed many of them.
If a 300w inverter will meet your needs I'd look at the Morningstar unit. It is very heavy duty. I suspect that if you're running 3 TVs plus the other stuff 300w won't be large enough.