Inverter advice

[KLF]

Did some searching here, didn't really see anything recent that leads me to a clear answer.

We need to power some surveying gear out in the field that only runs on 120V AC, and we need to also run a couple of laptops for post-processing of large amounts of data. We don't do this often, so I'm not in favor of getting a generator that needs to be maintained with fresh gas and oil. Current thinking is to just get an inverter and run it off the battery of a vehicle, since we'll always be able to have a vehicle near where we're working. We want something that will go up to 2000W.

Is there a brand in particular that you expo folks prefer? These things are available from many sources, but I'm betting that a lot of them are all the same guts inside, just a different sticker on the front. Anything made in the US? Preferred vendor?

We don't need mission-critical mil-spec stuff, but we do want it reliable.

 

[george_tlc]

2000W from 12V means drawing 2000W/12V = 170A..... So, if you plan to run this setup for any length of time, even just 20 minutes at full load you better have the engine running at HIGH idle and have a good alternator.

What is the ACTUAL power output you need at 120? i.e. take some power measurements to see if it is even feasible to do what you want.

cheers,
george.

 

[titanpat57]

Make your life simple and just get a Honda eu2000i and have everything you need.

Most inverters producing clean power that big will cost a lot more than the generator

If you get the Companion model you can hook two together and produce 220/30 amps if you needed to.

Plus it's quiet, fuel efficient. light, and will charge 12v if you get stuck with a dead battery

 

[KLF]

Make your life simple and just get a Honda eu2000i and have everything you need.

Hmm...

Honda EU2000i generator: $1000

http://www.campingworld.com/shopping/item/honda-eu2000i-generator-carb-compliant/34961

Requires maintenance, fresh gas, upkeep.

2000W inverter: $189

http://www.amazon.com/Cobra-CPI-257...lp_583328_1_23?ie=UTF8&qid=1362069120&sr=1-23

Requires... nothing. Well, a vehicle, but we have several of those to choose from already.

The 2000W estimate is an absolute peak and I really don't ever see going near that. The laser scanner really only draws about 300W, and a laptop maybe 100W.

We use this setup once or twice a year.

 

[titanpat57]

Big difference between an "inverter" and a "pure sine wave" inverter..which is recommended for electronic sensitive devices...

here's a link that has mucho helpful info(and prices)

http://www.donrowe.com/inverters/puresine.html

 

[Fast Eddy]

Big difference between an "inverter" and a "pure sine wave" inverter..

Yea, $128.77.

http://www.amazon.com/Sunforce-1126...78498&sr=1-3&keywords=pure+sine+wave+inverter

The 2000W estimate is an absolute peak and I really don't ever see going near that. The laser scanner really only draws about 300W, and a laptop maybe 100W.

We use this setup once or twice a year.

A cappucino maker or a blender is about 1000w. Just saying...

 

[titanpat57]

Yea, $128.77.

http://www.amazon.com/Sunforce-1126...78498&sr=1-3&keywords=pure+sine+wave+inverter

Cheap is expensive Dad....

 

[Fast Eddy]

I've been plugging stuff into inverters for many years, and have never had any damage yet.

 

[scrapdaddy]

Fast Eddy,

Is this Sunforce, a top of the line model. If the OP is set on a inverter, which is a good one? I would like to know myself.

 

[greentruck]

Big difference between an "inverter" and a "pure sine wave" inverter..which is recommended for electronic sensitive devices...

here's a link that has mucho helpful info(and prices)

http://www.donrowe.com/inverters/puresine.html

x2

You can power all the usual camping stuff off a cheap inverter and never notice the sloppy electricity it's supplying. Hook up laser printer and fancy surveying equipment and YMMV -- a lot.

 

[NLXTACY]

You have two types of inverters, mod-sine and pure-sine. Mod-sine are found in every KMart, Walmart, Checkers and Pep Boys. They all work perfectly fine and generally reliable. But you need to understand how they charge. Mod-sine is great for everything from a fridge to some cell phones to soldering irons to PSPs. But a Sine-wave, especially a good quality one like XANTREX, will last forever and will make sure the battery in your iPhone or your favorite laptop, doesn't die an early death. Sensitive electronics, use pure-sine. Non-sensitive motor type electronics, go to town on the cheapy inverters. I have a cheap mod-sine inverter in my LX and it has it's intended uses. The rule is no laptops and no cell phones. Everything else is fine (for our stuff).

FWIW, I 100% agree on the Honda generator. There is zero point, and plenty of risk, trying to pull 170A out of your charging system.

 

[EOE_overland]

Is 2kW related to some calculations you made, or just a number?
From the items you listed, you shouldn't need anything near that high a rating for inverters.
If you do need a 2kW inverter (vs a generator), you'll need more than to just hook it up to a vehicle start battery.
You'll need a battery bank (even if it is part of the vehicle system). An OEM start battery will get you nowhere running a larger inverter. It'll be dead in no time and you and crew will be sitting in the boondocks with dead cell phones and laptops . You would need a dedicated bank (preferably deep cycles) somewhere else in the truck or at a min, a dual battery setup in the truck with some safeguard to keep from killing the start battery. That adds to the cost. Then recharging...
An inverter isn't a bad idea for this application vs a generator, but there's more than connecting a 2kW inverter to your truck battery and heading off into the bush.
Realistically look at what you will need to run, roughly how long you will need it. For one day then home, or multiday?
Post up what you need. I'm guessing 2kW is way overkill. But if it isn't, there are a few more factors to throw in the mix.

 

[EOE_overland]

As far as brands, the amazon models are probably decent for occasional, not super important use.
For quality that costs a few more $, the Xantrex mentioned above is a good brand. I always like them because we had a semi-local shop in NJ that would repair them if they failed. Imagine that, actually fixing broken electronics instead of tossing them .
I really like Outback inverters. Pretty expensive and more suited to longer term off the grid use. But excellent product, great Support, and field serviceable!

 

[scrapdaddy]

This has been all good information, for a guy like me. Might not be a bad idea to have both on a long trip. I like back up plans.

Thanks, Ron

 

[KLF]

Like I said, 2000W is way overkill. I did bring in an ammeter today, I'm gonna fire up the devices and take some actual measurements and get closer to the truth of what we actually need. This is a $30K Leica Laser Scanner, so I want to protect it of course.

But I have to say that I don't get the concern about running a laptop from a cheaper inverter. I've done this MANY MANY times, and it's never been a problem. The AC adapter rectifies the sine wave (whatever shape it is) down to DC anyway. Maybe it's a lumpy DC, but I really don't think the battery cares.

We have a guy on staff here that's an EE, he really knows all about this stuff (he has worked for several TV and radio stations, and designs power supplies and antenna systems as a hobby, ya that kinda of a guy), so I guess I'll have to have a chat with him. Could involve some testing with his scope, which could get interesting.

 

[EOE_overland]

It doesnt have that complicated. Most important things are to sit down and think about all the things you will need to use. Read the rating on the power supply- for instance as someone mentioned most laptop PSUs are roughly 100w. Figure out what equipment you will need to run at the same time. Then figure out how long you expect to run them during the trip. For example, if you have 2-3 laptops with you, do they all need to charge at the same time? That will determine the max wattage you will need at a given moment. Most inverters are rated to allow for "startup" wattage as well, but that refers to a short spike when motors, etc startup. For extended use, you want to stay below the inverters normal rated use.
By determining how long and often you need to use the inverter, you can determine the battery bank size you will need.
It's not complicated, in fact there are easy little worksheets available to write in the stuff you will use to determine these answers. I have one kickin around up in my office; will try to find it today if I get up there .
My guess is your best bet is to find a better quality, lower watt inverter. Sounds like less hassle is a big factor, and bigger inverters require more.
If you are on the line with your needs for a smaller inverter, you can just charge one or two items at a time instead of everything.

And my $.02 is to leave the EE out of it . You'll end up more confused, angry, and probably with an unexplained nose bleed if you do .

 

[EOE_overland]

Here's a webpage with a rough calculator at the bottom. Not great, but will get you started.
http://www.theinverterstore.com/tips.html

 

[KLF]

I wasn't able to setup the laser scanner and fire it up, but I did take a look at the power brick. Says input is 3.2A @ 120V, which would be about 385 watts max. I also checked one laptop (Dell Latitude), and even though the power brick says it needs 100W, I measured about 0.4-0.5 A while charging the battery, so maybe 60W. So it's likely I'll be drawing less than 400W when running the scans.

I already have a 300W inverter (600W peak), I might see if it can run just the scanner as a test. I've used it many times to charge laptops and an iPad, no issues.

I'm still convinced an inverter is the way to go, I'm just looking for a good brand that is reliable.

 

[HJ-45CrewCab]

Ken, I would say the two big players are:

http://www.xantrex.com/power-products/power-inverters/overview.aspx

http://www.outbackpower.com/products/sinewave_inverter/mobile/

Both have experience making inverters from the range you are looking for to whole house back-up and solar systems. RV industry overwhelmingly uses Xantrex and its one of the few reliable components on my motorhome. IMO, Anything over a 1000 watts you will need deep cycle batteries, and a dual battery system to charge them from the vehicle. Otherwise, you will be running the vehicle engine constantly to just run the inverter. Much less hassle to do the Honda generator...which are bulletproof. If you do go with the inverter, make sure it has a low voltage shutoff so as not to drain the vehicle battery below its starting voltage threshold.

 

[landcrshr]

We use this setup once or twice a year.

If you do really need that kind of wattage only once or twice a year, just RENT the generator when you need it.