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Inverters Question [message #194086] Thu, 27 December 2012 01:45 Go to next message
SteveW is currently offline  SteveW   United States
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Happy Holidays all and THANK YOU for the wealth of expertise and information here.

Costco appears to haves good deal on a 2300 watt inverter:

http://t.costco.com/PowerBright-2300-Watt-12-Volt-Power-Inverter.product.11540208.html

They have a 1500 watt too:

http://t.costco.com/PowerBright-1500-Watt-12-Volt-Power-Inverter.product.11540218.html

Is there any sense in purchasing "more" inverter than one probably needs ??

A light load on a larger inverter - is that more efficient than a heavier load on a lesser inverter ??

Is there an optimal load for a given inverter capacity ??


Steve W
1973 23'
Southern California



Steve W 1973 : 23' Southern California
Re: Inverters Question [message #194090 is a reply to message #194086] Thu, 27 December 2012 07:02 Go to previous messageGo to next message
tphipps is currently offline  tphipps   United States
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It would not hurt anything to purchase the higher capacity inverter. Inverters are inefficient, and the larger one will deliver more power at less energy wasted as heat. Extra capacity never hurts.
Tom, MS II


2012 Phoenix Cruiser model 2552 KA4CSG
Re: Inverters Question [message #194091 is a reply to message #194086] Thu, 27 December 2012 07:44 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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SteveW wrote on Thu, 27 December 2012 02:45

Happy Holidays all and THANK YOU for the wealth of expertise and information here.

Costco appears to haves good deal on a 2300 watt inverter:

http://t.costco.com/PowerBright-2300-Watt-12-Volt-Power-Inverter.product.11540208.html

They have a 1500 watt too:

http://t.costco.com/PowerBright-1500-Watt-12-Volt-Power-Inverter.product.11540218.html

Is there any sense in purchasing "more" inverter than one probably needs ??

A light load on a larger inverter - is that more efficient than a heavier load on a lesser inverter ??

Is there an optimal load for a given inverter capacity ??


Steve W
1973 23'
Southern California

Steve,

There are only three real issues with installing a larger inverter:
1 - The quiescent load (standy by) load tends to go up with larger capability.
2 - The amount of copper required on the DC end will need to be larger and therefore somewhat more difficult to fit.
3 - The supplying bank must be capable at the inverter's full load.

If you can get and read the specifications, the quiescent load difference between 1500 and 2300 may be insignificant, but you really should look.

The copper required will go from something like 2AWG to 1 or 2/0AWG and the difference in cost may not be a big issue, but big cables get very hard to bend.

Finally, if your house bank is not something close to 230Amp/hrs, it will be over the edge in just a couple of minute at maximum load.

This all supposes that you will use all of the inverter capability, but it seems that is what usually happens.

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
Re: Inverters Question [message #194096 is a reply to message #194091] Thu, 27 December 2012 09:13 Go to previous messageGo to next message
WD0AFQ is currently offline  WD0AFQ   United States
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Steve, do you have enough battery to run a hair dryer, microwave, or vacuum cleaner? If not, you don't need the biggest one. Now, if you are looking down the road, thinking about a lot of dry camping, then it might be good to get a larger one. A tv will not require a very big inverter. I have seen better prices on similar inverters.
Dan


3 In Stainless Exhaust Headers One Ton All Discs/Reaction Arm 355 FD/Quad Bag/Alum Radiator Manny Tran/New eng. Holley EFI/10 Tire Air Monitoring System Solarized Coach/Upgraded Windows Satelite TV/On Demand Hot Water/3Way Refer
Re: Inverters Question [message #194099 is a reply to message #194096] Thu, 27 December 2012 09:41 Go to previous messageGo to next message
Don A is currently offline  Don A   United States
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sort of related question.

I use a cig lighter plugin inverter to power a netbook for Streets and Trips gps. The little inline brick converts 120v to 12v, max 3amps.

Would it work to plug the netbook directly to the coach 12?

Does the power brick provide any needed filtering or spike protection?

Both the inverter and the inline power brick get pretty warm and it seems like a waste to go to 120 and back.

Thanks for knowledge and experience.




Don Adams Dallas, TX
'76 26' Glenbrook, '90 Sidekick
rebuilt by R Archer, powered by J Bounds, Koba
[IMG]http://www.gmcmhphotos.com/photos/data/6109/G2.jpg[/IMG]
Re: Inverters Question [message #194100 is a reply to message #194099] Thu, 27 December 2012 09:51 Go to previous messageGo to next message
WD0AFQ is currently offline  WD0AFQ   United States
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Don, that should work but I would not do it. Id want something limiting the thing to 12 volts. When you fire up the coach your voltage is going up. Most all of my netbooks run on 19 volts. I use inverter or buy the 12volt plug for the particular laptop/netbook.
I do run my router directly off the 12 volts, using an adjustable cigarette plug.
Dan


3 In Stainless Exhaust Headers One Ton All Discs/Reaction Arm 355 FD/Quad Bag/Alum Radiator Manny Tran/New eng. Holley EFI/10 Tire Air Monitoring System Solarized Coach/Upgraded Windows Satelite TV/On Demand Hot Water/3Way Refer
Re: Inverters Question [message #194101 is a reply to message #194100] Thu, 27 December 2012 09:59 Go to previous messageGo to next message
Don A is currently offline  Don A   United States
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Thanks Dan

Making a direct plug would be easy. But I haven't found one to buy, which makes me think it is not a great idea. I sure hate the heat and the gaggle of long cords.

added

my other notebooks also are not 12v, but this one is


Don Adams Dallas, TX
'76 26' Glenbrook, '90 Sidekick
rebuilt by R Archer, powered by J Bounds, Koba
[IMG]http://www.gmcmhphotos.com/photos/data/6109/G2.jpg[/IMG]

[Updated on: Thu, 27 December 2012 10:00]

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Re: Inverters Question [message #194103 is a reply to message #194086] Thu, 27 December 2012 10:37 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
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try to use the factory power supplies. they do make some that have a cig. plug.

when you do have a power problem, spike or surge or something. it normally kills the adapter first. before it blows the power on the motherboard of the computer.

I deal with alot of laptops. it is pretty random what takes them out. with the exception of spilled beer. that is not good for a computer. not sure why that happens alot to construction laptops.




Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
Re: Inverters Question [message #194106 is a reply to message #194099] Thu, 27 December 2012 12:46 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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Don A wrote on Thu, 27 December 2012 10:41


sort of related question.

I use a cig lighter plugin inverter to power a netbook for Streets and Trips gps. The little inline brick converts 120v to 12v, max 3amps.

Would it work to plug the netbook directly to the coach 12?

Does the power brick provide any needed filtering or spike protection?

Both the inverter and the inline power brick get pretty warm and it seems like a waste to go to 120 and back.

Thanks for knowledge and experience.

Don,

For years, I had a laptop that was 12V. I made up a cord to power it from a DC mousehole. It worked fine. If the manufacturer can supply a 12V power cable, that would be my first choice. It will probably of some level of filter and/or spike trap in it. In a coach, I would also be careful to power it from the house bank and not the starting battery. To do that, you may have to add your own mousehole, but the power on the house side is always cleaner.

In my boat work, I have known of more than a few to have trouble running a netbook/notebook from the factory line power supply plugged into an inexpensive inverter. As both of those are going to be switching type power supplies, if they get in/out of sync, things can get very interesting.

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
Re: Inverters Question [message #194108 is a reply to message #194086] Thu, 27 December 2012 13:09 Go to previous messageGo to next message
habbyguy is currently offline  habbyguy   United States
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To be sure, an inverter just to power a laptop doesn't have to be all that big or expensive (and won't draw too much current).

When I decided to put an inverter in my rig, I did the calculations and came to the conclusion:
1) I'd like to have enough power to run a hand vacuum and my microwave (about 7 amps of 120VAC).
2) I'd never have enough battery capacity for running anything bigger, which would be the roof A/C units.
3) It should be big enough to be able to run the fridge on A/C when driving.
4) There's no use in buying a bigger inverter than I need because of the potential for more "resting current" when it's just sitting there running at a small percentage of its capacity.

This all led me to buy a 1000 watt inverter from Harbor Freight (for chump change). I checked the "resting current" and it draws about 1.1 amps at 12VDC without a load. I even went so far as to put a thermal switch in the fan circuit so they didn't run until the internal heat got to about 140 degrees, but that only knocked off about 0.25 amps.

The other thing about my installation was that (because of the way my Royale is set up), the inverter is located in the left rear corner, and the house batteries in the right front. I ended up buying 25' of 1/0 "power amplifier" cable, which is VERY flexible (you could form it into a 6" radius curve without difficulty), for running from the front around all the "interesting stuff", then connected it to another 10' or so of 2/0 "regular" cable (about as flexible as PVC pipe). This wasn't a problem though, since I just poked it back through the frame holes, where the stiffness actually works to keep it out of trouble.

The other thing I had to learn was that the inverter needs to be grounded to the aluminum frame, NOT the steel chassis or the A/C neutral "ground". As a result, my inverter has no issues supplying a full 7 amps of AC power to run my vacuum, and will run my (old) microwave as well (though not at the same time). I remoted the on/off switch to my generator panel, with an obvious indicator light that makes it easy to remember to turn off the inverter before starting the generator. I also home-brewed an autoswitch that will keep the two (generator and inverter) from getting into a nasty (and expensive) fight, should I ever forget to turn off the inverter, and so I don't have to flip any breakers or heavy switches to run my inverter.

The end result was a big increase in the utility of my GMC, with an investment of around $200 (and some hours, of course).


Mark Hickey Mesa, AZ 1978 Royale Center Kitchen
Re: Inverters Question [message #194110 is a reply to message #194086] Thu, 27 December 2012 13:38 Go to previous message
bwevers is currently offline  bwevers   United States
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Steve,
I tried one of those "Modified Sine Wave" inverters to
power my TV. The TV made a loud buzzing noise, not good.

I replaced it with a "Pure Sine Wave" inverter.
More expensive, but better.

Regards,
Bill


Bill Wevers GMC49ers, GMC Western States 1975 Glenbrook - Manny Powerdrive, OneTon 455 F Block, G heads San Jose
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