What Brand and Watt Inverter Do You Have

[Melbo]

What size and brand name inverter are you using in your GMC and what do you power from them. Did you have to upgrade your alternator or do you run a
stock alternator. My plan is to use the stock alternator and 2500 watt inverter which will handle 20 amps at 120 volts. But if I am missing something
and should go larger or could go smaller it would be good to know before I part with the money and have to start over. The main thing that I think I
would be powering is the refrigerator. On the road sometimes passengers want to watch TV so that is also a consideration. I am looking at pure sine
units just because that is what I have used in the past. Ken sent me an excellent diagram so I have a good plan to wire things up but my question now
is size and brand name. I am familiar with Magnum inverters but I think that is overkill.

I realize that asking what is best is opening a can of worms so I am really just asking what has worked for you in terms of brand name and size.

Thanks

Melbo
--
Albuquerque NM Bus Conversion 1978 MCI 1973 GMC

 

[Jim Hupy]

I use a Progressive Dynamics with the magic box that monitors state of
charge of the batteries. Leave it plugged in all the time. Check the water
in my Trojan batteries a couple of times a year. Seldom need water. Just
sits there and does it's job quietly. My transfer switch makes more noise
than the PD does. I do check electrical connections at the same time. They
need more looking after than anything else in the coach. Don't neglect them.
Jim Hupy
Salem, Oregon

On Sun, Jan 3, 2021, 5:17 PM melmull--- via Gmclist
wrote:

> What size and brand name inverter are you using in your GMC and what do
> you power from them. Did you have to upgrade your alternator or do you run
> a
> stock alternator. My plan is to use the stock alternator and 2500 watt
> inverter which will handle 20 amps at 120 volts. But if I am missing
> something
> and should go larger or could go smaller it would be good to know before I
> part with the money and have to start over. The main thing that I think I
> would be powering is the refrigerator. On the road sometimes passengers
> want to watch TV so that is also a consideration. I am looking at pure sine
> units just because that is what I have used in the past. Ken sent me an
> excellent diagram so I have a good plan to wire things up but my question
> now
> is size and brand name. I am familiar with Magnum inverters but I think
> that is overkill.
>
> I realize that asking what is best is opening a can of worms so I am
> really just asking what has worked for you in terms of brand name and size.
>
> Thanks
>
> Melbo
> --
> Albuquerque NM Bus Conversion 1978 MCI 1973 GMC
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[Carl Stouffer]

I have a 750 watt Harbor Freight inverter. It powers a 19" TV/DVD combo and our laptop computers (two of them) and runs battery chargers etc just
fine. When I was looking for one, I asked a friend who is fluent in electronics, what to get. He suggested a cheap modified sine wave inverter from
Harbor Freight and to get the extended warranty. That was about 11 years ago and I have had zero issues with either the inverter or what it powers.

I'm not suggesting that a pure sine wave inverter would not be a better choice, I'm just relating what I did and how it has proven more than
satisfactory. I used a Kill-a-Watt meter to check the electrical draw of the things we wanted to use and it was only about 350 watts total, so at
John's suggestion, I doubled that.

We do not try to run a coffee maker (using a "Presto My Joe" instead) or a microwave or any other high draw appliances while dry camping, opting
instead to use the stove-top (propane) or to grill outside.

I also have a small solar system (195 watts total) which generally replenishes the two GC-2 batteries by mid afternoon, and a three way fridge running
on propane when not plugged in.

JWID.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member

 

[adolph santorine]

Sine wave vs. Modified Sine wave, or power quality is part of the answer you are looking for, and charging capability is the next.

If you’re buying an all in one box, my recommendation would be to get one that will easily handle future battery technology, meaning not only the flooded cells you’re used to, but AGM, SiO2 and LiFePO4. The latter two are coming down in price tremendously, and that will likely continue.

That’s the charge side. Now for the inverter:

Modified Sine Wave inverters make something that approximates a sine wave (what you get from the power company) in the least expensive way possible, and generally have 20% or more harmonic distortion. Two things will happen - first, if you put a cheap voltmeter on the output, it will read something like 90 volts. Only a true RMS voltmeter will give you an accurate reading.

Second, any motor you attach to it will heat up more than usual. In a lot of applications, it really does not matter. Fans don’t care. Power tools don’t either. Refrigerators may or may not care.

Sine wave inverters make nice, low distortion 60 hz waves, just like you get from the power company.

I have a Xantrex Pro Sine 2000. It does a terrific job, and I can program the charging curve to properly charge many LiFePO4 batteries (with a good BMS). It’s about half way through it’s life cycle, and i can see me using it for another 10 years.

Now for some real numbers. When I had a residential fridge, it looked for about 135 watts… at 120 volts that’s 1.125 amps or so.

Ten times that at 12 volts, plus 10% inverter losses, or 12.5 amps

The coffee maker looks to the batteries for about 115 amps when it’s running.

The microwave goes looking for about 1,400 watts (1,250 watt in the oven, plus 150 for the light/turntable and overhead).

That’s 160 amps or so from the batteries.

Since those are the big draw in our coach (no TV, and trying to power the AC is not a consideration), there you have it.

Those are real life measured numbers.

Dolph

DE AD0LF

Wheeling, West Virginia

1977 26’ ex-PalmBeach
Howell EFI & EBL, Reaction Arms, Manny Transmission

“The Aluminum and Fiberglass Mistress”

|[ ]~~~[][ ][] \
"--OO--[]---O-"

>
> What size and brand name inverter are you using in your GMC and what do you power from them. Did you have to upgrade your alternator or do you run a
> stock alternator. My plan is to use the stock alternator and 2500 watt inverter which will handle 20 amps at 120 volts. But if I am missing something
> and should go larger or could go smaller it would be good to know before I part with the money and have to start over. The main thing that I think I
> would be powering is the refrigerator. On the road sometimes passengers want to watch TV so that is also a consideration. I am looking at pure sine
> units just because that is what I have used in the past. Ken sent me an excellent diagram so I have a good plan to wire things up but my question now
> is size and brand name. I am familiar with Magnum inverters but I think that is overkill.
>
> I realize that asking what is best is opening a can of worms so I am really just asking what has worked for you in terms of brand name and size.
>
> Thanks
>
> Melbo
> --
> Albuquerque NM Bus Conversion 1978 MCI 1973 GMC
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[LQQKatJon]

I have a xantrex inverter I think 1000 or 1500 watt sitting on my bench not installed. It was given to me by someone else who never installed it.

I do plan on install it this spring... What i have learned is an inverter is not as easy to install as one might think.

the need for the heavy 2 or 4 awg wiring, fusing, and trying to split loads, and figure out the transfer switching between shore power, generator
power and inverter power. I also want ability to make sure I can cut power to the inverter, because I sometimes do not want the drain of the inverter
not being used.


I have found that I really have not had the need for an inverter. Even when my generators were not working this past summer on our 4000 mile trip,
we did not miss the generator other then for roof air. My current thoughts is to install it and just wire up one or two completely separate
outlets. I can maybe see the need for use for the coffee pot or microwave. TV's are normally 12v these days, or can be found as a 12v.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/

 

[Carl Stouffer]

One of the reasons I went with a smaller inverter was that I didn't need to run huge cables to it. Here's what I did:

http://www.gmcmhphotos.com/photos/gmc-tv-mount/p41551-inverter.html

http://www.gmcmhphotos.com/photos/gmc-tv-mount/p41554-inverter-outlet.html
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member

 

[richshoop]

Anytime you are adding an electrical device to the coach, you must consider the additional load. In regards to inverters, consider a 750 watt inverter. 12V at 750 watts is 62.5 amps, requiring #6 wire at a minimum. If the wire run is more than 5 feet or so, you need #4 wire. And be sure to run a black negative wire back to the battery, do not use a wire connected to the frame of your coach. This arrangement will allow you to use the basic Mr. Coffee machine as sold at CVS for your morning brew.

>
>
> One of the reasons I went with a smaller inverter was that I didn't need to run huge cables to it. Here's what I did:
>
> http://www.gmcmhphotos.com/photos/gmc-tv-mount/p41551-inverter.html
>
> http://www.gmcmhphotos.com/photos/gmc-tv-mount/p41554-inverter-outlet.html
> --
> Carl Stouffer
> '75 ex Palm Beach
> Tucson, AZ.
> Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
> Solar battery charging. GMCSJ and GMCMI member
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[johnny]

I've a 750 rackmount UPS which I intend to put in my coach. Step - wave output. I needto take it out of the mount, buy or make a box for it, and
mount it in the 12volt supply/breaker box where the cable run is close.

--johnny

--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell

 

[Matt Colie]

We have years of experience with the 750/1500 modified square wave inverter from Hazard Fright. It was cheap. Our OE died suddenly and we were less
than a week from scheduled departure. So, I bought that, a dorm reefer. I had #6AWG on hand but when I tried to bend it to fit, it didn't cooperate
at all. So, 3*#10 = #7 Close enough and I have lots of #10THHN in stock. We went to our destination with a 14-3 extension cord from the right side
of the glove compartment to the reefer. My inverter live in the right side of the glove box because our coach is a 23 with the house bank in the
front.

We replaced the dorm single door with a two door because Mary was not happy with both the performance and the convenience of that unit. It got sold
at a little less than break even. About a year later, just a short time after that departure, the inverter let some smoke out. I had installed it
with a resetable breaker, so we got off the highway and I jumped out and tripped the breaker manually. We knew right where the nearest HF was so, I
got a replacement off the shelf (with the protection plan this time). I installed it while we were underway, but we did have to pull into a rest area
for me to reset the breaker.

Final assessment: The reefer change cost us a little, but they were about 125$us. The inverter was 40$ on sale and the replacement was not on sale,
but I used the protection plan to replace the one that leaked smoke. So, I have a spare. A replacement LP/120 was 1200$us and not real available and
the coach has no LP service to the reefer area. I was worried about the nearly square wave power to the compressor, but I carry an IR gun (every GMC
should) and early on I did check the temperature of the compressor. On the inverter, it seems to run about 3~5°f higher than it does on shore power.
It also runs a little warmer on the APU. I have never had a scope on the Onan so I don't know how much distortion it produces.

Of course I made the obligatory promises to my self that this was a temporary install and I would clean it and install better gear when practical. In
the intervening decade, I did bury a 14-3 run of stranded NM in some wire mound so it isn't hanging out to be tripped over. This also provides 120VAC
for other small loads or some larger loads for short times.

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

 

[Melbo]

Thank You All for the information. I am making up a plan and using a lot of the information that was given.

The plan will probably be changed multiple times before I am completely done but you have provided some GREAT information.

This is a great winter time project. It would be nice to get some travel in this summer. We will see what the world looks like in the spring.

Thanks again

Melbo
--
Albuquerque NM Bus Conversion 1978 MCI 1973 GMC

 

[LarryW]

In 2005, I bought and installed a TRACE Truck Series 1000W Inverter Converter Charger. Installed it with a ATS (Automatic Transfer Switch) This is a
Modified wave inverter. The only thing I have not been able to run on 120v inverter power is an electric blanket that we had for a while. It had an
electronic control of some kind and when on inverter, the controls just flashed and would not heat. When on shore power it worked fine. So, we bought
a different blanket that had dual controls ...what appeared to be analog in nature. This blanket works fine on inverter, though we almost never use it
that way. We also use the inverter all of the time with a small crockpot. When traveling long haul, putting in long days on our way Wisconsin to
Florida or California, Lucy will fill the crockpot with some favored recipe, plug it in, and at noon, turn on the inverter. We have a nice hot meal at
the end of the day waiting for us. We set the crockpot down in the bathroom sink. Fits snug in the sink, so any sudden movement around corners or
stopping, the crockpot is safe. Just what we do.
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.

 

[Ron Clark]

We use our crockpot much the same.
Set it up before we leave, in the morning, and by dinnertime, it's ready
to eat.
Difference is that we use a 12 volt crockpot, and it's in the galley
sink.

On Tue, 05 Jan 2021 19:29:00 -0700 Larry via Gmclist

>

We also use the inverter all of the time with a small
> crockpot. When traveling long haul, putting in long days on our way
> Wisconsin to
> Florida or California, Lucy will fill the crockpot with some favored
> recipe, plug it in, and at noon, turn on the inverter. We have a
> nice hot meal at
> the end of the day waiting for us. We set the crockpot down in the
> bathroom sink. Fits snug in the sink, so any sudden movement around
> corners or
> stopping, the crockpot is safe. Just what we do.
> --
> Larry
> 78 Royale w/500 Caddy
> Menomonie, WI.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[RF_Burns]

One thing you should consider is the larger the inverter, the more power it consumes itself. So a 2500W inverter might consume 2 amps with no power
draw from it, whereas a 1200W unit might consume less than 1 amp.

Two amps may not seem like much, but take a 12 hour over night stay that's 2A x 12hrs = 24Amp hrs. So say you have a 100Amp-hr deep cycle battery
that you don't want to discharge to more than 50% (now 50amp-hrs), that's 1/2 of your usable battery capacity.

You mentioned you want to run the fridge from it, so I am assuming you have an all electric fridge. Like Matt, we also run an all electric fridge. I
use a 1200W sine wave inverter from a 100Amp-hr battery. We can do an over-night off-grid, but we don't run the microwave or coffee maker from the
inverter. For heavy loads I'll start the generator. We have run the microwave or coffee maker while on the road, but never at the same time.

I used a Samlex EVO-1212 Inverter/charger/transfer switch. It charges (smart charger with multiple charging profiles including LiFePo4) and
seamlessly transfers in-phase between shore power to inverter and back. It also accepts charging power from solar panels.
https://www.samlexamerica.com/products/ProductDetail.aspx?pid=605

You might also want to read this article on converting from lead-acid to LiFePo4 batteries. I'm considering that move over this winter.
https://marinehowto.com/lifepo4-batteries-on-boats/

--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that

 

[dave silva]

> One thing you should consider is the larger the inverter, the more power it consumes itself. So a 2500W inverter might consume 2 amps with no
> power draw from it, whereas a 1200W unit might consume less than 1 amp.
>
> Two amps may not seem like much, but take a 12 hour over night stay that's 2A x 12hrs = 24Amp hrs. So say you have a 100Amp-hr deep cycle battery
> that you don't want to discharge to more than 50% (now 50amp-hrs), that's 1/2 of your usable battery capacity.

With that in mind, it seems like there might be some value in having more than one inverter?

like maybe a 400 watt that stays on for charging laptops and whatnot and then a bigger one that you select when you need to make coffee or run a
microwave?

Perhaps a dedicated low power inverter outlet?

--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.

 

[dave stragand1]

Bear in mind, there are also 12v laptop power supplies out there from
the different PC manufacturers and aftermarket. These adapters
(DC-to-DC) are much more efficient than using an inverter to power an AC
adapter (DC-to-AC-to-DC).

-Dave
1978 Transmode near Pittsburgh

-----Original Message-----
From: Gmclist [mailto:gmclist-bounces] On Behalf Of dave
silva via Gmclist
Sent: Wednesday, January 06, 2021 8:48 AM
To: gmclist
Cc: dave silva
Subject: Re: [GMCnet] What Brand and Watt Inverter Do You Have

> One thing you should consider is the larger the inverter, the more
power it consumes itself. So a 2500W inverter might consume 2 amps with
no
> power draw from it, whereas a 1200W unit might consume less than 1
amp.
>
> Two amps may not seem like much, but take a 12 hour over night stay
that's 2A x 12hrs = 24Amp hrs. So say you have a 100Amp-hr deep cycle
battery
> that you don't want to discharge to more than 50% (now 50amp-hrs),
that's 1/2 of your usable battery capacity.

With that in mind, it seems like there might be some value in having
more than one inverter?

like maybe a 400 watt that stays on for charging laptops and whatnot and
then a bigger one that you select when you need to make coffee or run a
microwave?

Perhaps a dedicated low power inverter outlet?

--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.

_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[dave silva]

> Bear in mind, there are also 12v laptop power supplies out there from
> the different PC manufacturers and aftermarket. These adapters
> (DC-to-DC) are much more efficient than using an inverter to power an AC
> adapter (DC-to-AC-to-DC).
>
> -Dave
> 1978 Transmode near Pittsburgh

Too much trouble too many devices- i have kids. this conversation has really inspired my thinking. i have a little countertop behind the dinette,
perfect for phone and tablet charging. There is a 12v outlet and a 120VAC so the wiring is there for a small inverter.

I can hardwire a big one alongside the converter on the other side of the coach. I may need to work out some power transfer to prevent one from back
feeding the other but that should not be too tricky
--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.

 

[Stu Rasmussen]

While recently outfitting my locksmith work truck that's what I did - I
installed a 600 watt Xantrex pure sine wave unit scrounged from another
vehicle and purchased a Freight, Harbor 2000 watt 'modified square wave'
one.

The Xantrex powers 'sensitive' stuff 24/7 and the 2Kw is switched on
only when dirty power is needed for motors, etc.

I think I will do the same thing with the Birchaven, putting the
inverters close to the front for shortest fat battery connections and
running 120 volt lines back to the power distribution area. Luckily I
have some 2/0 welding leads (also scrounged) that make the snaking of
wires pretty easy. Also got big fat 250A fuses at NAPA to protect the
primary wiring from battery to the inverter.

Haven't had the HF unit long enough to really give it a workout or test
longevity but so far works fine and only $170 (130 on sale).

JWID

Stu

> With that in mind, it seems like there might be some value in having
> more than one inverter?
>
> like maybe a 400 watt that stays on for charging laptops and whatnot
> and then a bigger one that you select when you need to make coffee or
> run a
> microwave?
>
> Perhaps a dedicated low power inverter outlet?
>
>
>
> --
> Dave & Ellen Silva
> Hertford, NC
>
> 76 Birchaven, 1-ton and other stuff
>
> Currently planning the Great american Road Trip Summer 2021
>
> It's gonna take a lot of Adderall to get this thing right.
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[Matt Colie]

> Too much trouble too many devices- i have kids. this conversation has really inspired my thinking. i have a little countertop behind the dinette,
> perfect for phone and tablet charging. There is a 12v outlet and a 120VAC so the wiring is there for a small inverter.
>
> I can hardwire a big one alongside the converter on the other side of the coach. I may need to work out some power transfer to prevent one from
> back feeding the other but that should not be too tricky

Dave,

We got by for years with first a 60watt that I cold plug into a DC mousehole (I hate those things) and later with a 300W MsqW that was still good
enough to change and run the laptop and the inkjet printer. So, yes that is a liable solution.
I only installed the big thing to run the replacement reefer.

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

 

[john r. lebetski]

Stock 80A Delcotron. Let’s call it 70A continuous to be generous. At 14VDC that’s 980 Watts available for all 12V systems. Lights, ignition and
dash fan chip away at that total to give a lower available number. . If you exceed that long term your batteries will be at a deficit.
--
John Lebetski
Woodstock, IL
77 Eleganza II