Power inverters

[Bombsight]

Where is yours mounted?
What do you power with it?
Recommended?
Anything else we should know?

Thinking about installing one of these:

 

[Stalking Light]

I have a GoPower 1500w mounted under my sink. I mostly only use it for a toaster, though, and to run the battery charger for my Nikon D4s. If I could figure out a place to stow a small microwave I'd use it for that too since I'm mostly too lazy to cook real food when I'm by myself.

 

[K6ON]

Mine is mounted under the front seat along with 2 100ah batteries in my Grandby. I power a small microwave, laptop, coffee grinder, run a LED video projector for showing movies on the side of the camper, and just about anything else I can think of. Been in the camper for 9 years and runs flawlessly.

 

[craig333]

Mines right next to my batteries. Runs pretty much the same as bob except I don't have a projector, thats just crazy

 

[DonC]

How in the world do you guys power microwaves, toasters, etc? I'd love to be able to do that but always assumed my two camper batteries would be drained in minutes.

 

[Bombsight]

Do you guys have dual batteries and is it connected directly to them?
Does it matter how you mount it (up, down on its side?) ?
Noisy?

Thanks

 

[K6ON]

Yes, dual batteries in parallel with the inverter connected directly to them through a 200 amp fuse. Wire length to batteries is about 16 inches of #0 cable. My inverter is quiet, although it has a fan that will come on if it warms up. Since it's under the seat, and I'm old and deaf, fan noise isn't an issue. Inverters don't care how they are mounted, sideways, etc.

DonC, understand the microwave only runs for a couple minutes, I think 10 minutes is about the max I've ever used it to bake a couple potato's. I don't run a toaster, but, how long does it take to make toast, 2 minutes maybe? My inverter has been in the camper for about 9 years, and never had an issue with batteries.

Craig, It's an LED projector, very low current

 

[Marc]

Have a go Power 1500 mounted on the side of my Galley cabinet used primarily for the microwave.

 

[Casa Escarlata Robles Too]

I have just a 150w mounted next to the battery.
Use it for charging batteries,coffee grinder.
Don't have a need for anything bigger.
Frank

 

[DonC]

approx how many amps will 10 minutes of a small microwave consume? In summer heat or winter cold, my frig or heater takes my batteries down to 70 - 75% each night. Any lower than that from running a microwave and I worry about my 200W of solar being able to fully recharge the batteries by the end of the day, especially if there is a cloudy day.

 

[Wallowa]

approx how many amps will 10 minutes of a small microwave consume? In summer heat or winter cold, my frig or heater takes my batteries down to 70 - 75% each night. Any lower than that from running a microwave and I worry about my 200W of solar being able to fully recharge the batteries by the end of the day, especially if there is a cloudy day.

Good question Don,

Those using permanently installed and rather hefty inverters on a regular basis must have some secret formula to keep the batteries up and running when camping off the grid...at least with the stock FWC AGMs. I am all ears and would like to hear how the draw on the batteries can be compensated for with regular, heavy use of an inverter. If it is a slam dunk we might go with a permanent one.

I have a small "Coleman" inverter that can handle up to 400w draw that we use only to grind morning coffee...it plugs into the FWC DC outlet on the cabinet by the sink in our Hawk...and stows in the draw below the plug when not in use.

 

[camelracer]

I have a small Coleman inverter that plugs into the 12v outlet for when I need a little 120v power.

When I installed my solar system the instructions for the Morningstar Sunsaver 15 controller said not to run an inverter of any size through the Sunsaver load terminal. I don't understand why they have this limitation so I wired the 12v outlet to the battery. If anyone can explain this limitation please explain.

 

[Bombsight]

Thank you very much for all of the info.
Is 3000 watts more than what is typically needed? What might be a minimum watt requirement?

 

[tree]

I have a zamp 600w pure sine inverter mounted on lower panel side of battery cabinet, and right above it is 3 switch power panel from bass pro. I use the inverter to power a led screen and dvd player. and charge cellphone. sometimes to charge dewalt batteries for the outdoor dewalt radio. you cant go wrong with a portable solar panel/charger and an inverter. I even sold my Honda 2000 generator.

 

[K6ON]

approx how many amps will 10 minutes of a small microwave consume? In summer heat or winter cold, my frig or heater takes my batteries down to 70 - 75% each night. Any lower than that from running a microwave and I worry about my 200W of solar being able to fully recharge the batteries by the end of the day, especially if there is a cloudy day.

A small 600 watt microwave isn't really a 600 watt load on your inverter. That 600 watts rating is cooking power, In reality a small microwave draws about 1000 watts from the power source. To figure out approximately how much current is being drawn by your inverter, let's presume it's 100% efficient (it isn't, but close). We'll also presume you have no voltage loss in your cable run to the inverter. To calculate current drawn from your batteries, divide the watts by your battery voltage. Let's say your batteries are at 13.2 volts and your inverter is drawing 1000 watts. 1000/13.2 = 75.75 amps. 75.75 amps a significant amount of current (why you need large wire for the inverter), but it's only being drawn for a couple minutes. Once the inverter is off, the batteries will recover most of their capacity in a few minutes. If you're going to run an inverter, I would suggest at least 2 100 AH batteries in parallel (YMMV).


Camelracer: Dick, the only reason they don't want you to run an inverter through your controller is the wire size is too small and you'll let all the smoke out.

Bombsight: A 3000 watt inverter is overkill, a 1500 watt inverter will cover pretty much anything you'll run in your camper.

 

[Wallowa]

A small 600 watt microwave isn't really a 600 watt load on your inverter. That 600 watts rating is cooking power, In reality a small microwave draws about 1000 watts from the power source. To figure out approximately how much current is being drawn by your inverter, let's presume it's 100% efficient (it isn't, but close). We'll also presume you have no voltage loss in your cable run to the inverter. To calculate current drawn from your batteries, divide the watts by your battery voltage. Let's say your batteries are at 13.2 volts and your inverter is drawing 1000 watts. 1000/13.2 = 75.75 amps. 75.75 amps a significant amount of current (why you need large wire for the inverter), but it's only being drawn for a couple minutes. Once the inverter is off, the batteries will recover most of their capacity in a few minutes. If you're going to run an inverter, I would suggest at least 2 100 AH batteries in parallel (YMMV).


Camelracer: Dick, the only reason they don't want you to run an inverter through your controller is the wire size is too small and you'll let all the smoke out.

Bombsight: A 3000 watt inverter is overkill, a 1500 watt inverter will cover pretty much anything you'll run in your camper.

K6ON,

As usual a great review...BUT Don's question seems to still be on the table...you stated that the batteries will "recovery most of their capacity in a few minutes"...you lost me there; what are the assumptions?...first I do not believe my FWC AGMs in the our '16 Hawk are 100ah, probably 80s...next my roof mounted and portable at best are rated at 240w...like Don says with 'other consumption' and not 100% solar production would not a large inverter use seriously draw the FWC batteries ?

My puny Coleman inverter might hit 400w momentarily with my coffee grinder but even that makes me nervous before sun up and with the heater fan going full tilt...hopefully the sky is not falling and a decent inverter can be supported inside my Hawk by the existing system [batteries and wiring].

Thanks for any insights...

Phil

 

[Bombsight]

Bombsight: A 3000 watt inverter is overkill, a 1500 watt inverter will cover pretty much anything you'll run in your camper.

Thanks for that input. I really didn't want to drop a grand on something I will seldom use. I think instead, I'll get the 2000 watt Go Power.
I'm stumped as to where to mount it though.

 

[JaSAn]

. . . you stated that the batteries will "recovery most of their capacity in a few minutes"...you lost me there; what are the assumptions? . . .

When filling a tire with an air tank and watch the air pressure gauge you will notice that the air pressure drops when you put the chuck on the tire and rebounds when you remove it. How far it rebounds depends on how much air you take out of the air tank. The same differential equations govern an electric system: pressure ≈ voltage, air volume ≈ amperage. Take a little air/amps out, pressure/voltage will rebound to almost where it was before starting. Take a lot of air/amps out and the pressure/voltage will not rebound as much.

Same equations govern electrical, hydraulic, & pnumatic circuits. As a mechanical engineer, when confronted by an electrical circuit that I didn't understand I would convert to the hydraulic analogs because I understand those circuits better.

jim

 

[Wallowa]

When filling a tire with an air tank and watch the air pressure gauge you will notice that the air pressure drops when you put the chuck on the tire and rebounds when you remove it. How far it rebounds depends on how much air you take out of the air tank. The same differential equations govern an electric system: pressure ≈ voltage, air volume ≈ amperage. Take a little air/amps out, pressure/voltage will rebound to almost where it was before starting. Take a lot of air/amps out and the pressure/voltage will not rebound as much.

Same equations govern electrical, hydraulic, & pnumatic circuits. As a mechanical engineer, when confronted by an electrical circuit that I didn't understand I would convert to the hydraulic analogs because I understand those circuits better.

jim

I think I understand that...but voltage vs amperage [pressure vs volume] seems to highlight the problem...I believe the amount of amperage is most critical not the voltage...40ah battery at 13.6 volts vs an 80ah battery at 13.6 volts....in my Hawk, amperage is the currency I spend with appliances [no joke intended with 'currency']...."pressure" may be up but "volume" deliverable may be down..

Phil

 

[DonC]

I have another bit of confusion here that will display my complete lack of understanding of my FWC systems. I have a standard Fleet build that includes lights, heater, electric fridge, solar. It has two 120v plugs that I think only work with shore power - I don't know as I've never used them, and never camped in a campground, let alone one that has electric. What I do use are the two 12v receptacles - I plug in a 300w inverter to charge my laptops and other devises.

With these inverters used for a microwave or other devises, is this simply a larger inverter that plugs into the 12v receptacle?

If wiring from the 12v is inadequate for these larger devises that are only used occassionally (for me) would something like this help that connects directly to the batteries
https://www.amazon.com/BESTEK-Battery-Cigarette-Lighter-Extension/dp/B00JOY6U7U