Power Inverters

Discussion in 'GM Electrical Tech' started by Crawdaddy, Apr 10, 2012.

  1. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    I am looking for a power inverter for my Suburban, but I haven't the foggiest idea where to start shopping for one that fits my needs/wants. So, I guess I'll outline what I need and want:

    • Must be narrow enough to fit in approximately 12" of width (I'll double-check this measurement when I get home)
    • Height is approximately 12" of height (again I'll double-check when I get home)
    • Would like remote power switch capability, but I can live without if it meets my other requirements
    • Would like 3000-5000 watts of power, but I will downsize power rating until I can find something that fits
    • Would like true sine wave power, but I think I can deal with modified sine wave

    So, with those in mind, where should I look for a QUALITY inverter to buy and does anyone have any tips for what I should be looking for? Something I can get locally is always better than internet, and a well-known and established website is always better than one I've never heard of before.
  2. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    I don't have an inverter for my truck but I keep wanting to put one in, as I have the electrical upgrades to easily support one. The trouble is I want true sine wave and the space I have allotted for the unit is too small for the wattage I want to support -- so I've done nothing other than dig around (a lot). This means I have theoretical knowledge ... but no practical experience with any particular inverter.

    I trust you know that 3000-5000 watts of power is going to mean a VERY heavy gauge cable coming through the firewall to get juice from the battery to the inverter if you're putting it inside the cab ... and you'll need to consider voltage drop across your distance when sizing that cable. Also, true sine wave inverters will be much larger and more expensive than modified; note the dimensions and cost of this 3000W unit (provided just for size/cost purposes; i.e. not a recommendation): http://www.invertersrus.com/powerbright-xtw3000-12.html

    Takeaways from this:

    • You didn't mention a budget; you need to determine what you have to work with.
    • You really need to decide on true sine wave or modified sine wave before you begin looking, as pricing and sizing will be very different.
    • You gave width and height but neglected length. Length needs to be considered, too, as inverters come in many shapes.
    • You need to consider your distance from the power source and plan cabling for it. Heavy gauge cable is not cheap and it is labor intensive to run. Most large inverters are intended to be clipped to the battery and run very close to it via short cables; the father you place it from the battery the bigger the cable is going to need to be. This is in addition to the higher the wattage you intend to support the bigger the cable is going to need to be.
    • You need to consider the heat the unit will produce at those wattages and make sure you've got airflow for it.
    • Do you want a unit that trickles when there's no power demand on it? If so look for that ... as not all inverters have it and it's the difference between one that drains your battery when on without load ... and one that doesn't.
    • 12v or 24v?
    • When looking at inverters pay VERY close attention to the input voltages that their wattages are based upon. Some inverters only achieve their maximum output at voltages that a battery simply won't produce, by itself, when the vehicle is off ... and which will only be produced with either a bank of batteries or with an upsized alternator that's running well beyond idle speeds. You'll typically need to dig into the manual for a particular inverter to find this data for that inverter.

    Answer those questions and couple it with your desire for a remote switch and you'll have a beginning on what to look for. Plan to narrow your inverter results and then dig through manuals...
    Last edited: Apr 10, 2012
  3. The Heater

    The Heater Rockstar 100 Posts

    Hi, Crawdaddy:

    What will you be powering with the inverter?

    As long as you are not using a computer or Hi Def television, the considerably more money you would pay for a true sine wave inverter is not really justified in my opinion. If you use it for standard camping stuff like a toaster or a small microwave, blender, and similar smaller appliances, the only thing that might need more than a 2000 watt inverter would be the microwave.

    Some appliance battery chargers are fussy about the inverter electricity (true sine wave versus non true sine wave). Another possible issue depending on your use. The quick chargers that are used on newer cordless lithium ion battery tools may or may not have issues if the inverter is not a true sine wave supply.

    I am trying to figure out why you want one that is a whopping "3000-5000 watts"? All those inverters I have seen are big, and they require more space and ventilation for cooling. That is a potential issue with all inverters. You must mount most or all of them in a position where they are able to get adequate ventilation and have heat dissipation without catching anything on fire in case they overheat.

    If you decide you don't need a garagantuan unit and could live with a 2000 watt unit, check Costco. They sell a good one, or at least they did last summer, that I have used for camping, and for most things it works fine. (I don't run a microwave with it). I run two deep cycle Interstate batteries to power it.
  4. moogvo

    moogvo Epic Member 5+ Years 1000 Posts

    Heater, you should be able to run a microwave on that. most microwaves are 800 - 900 watts.
  5. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    My original idea for the massive capacity was to plug in my camper when parked on the side of the road overnight, but I've since rethought the situation and will probably utilize a generator for that. I do still want an inverter though for powering utility loads like laptops, perhaps a desktop computer or two once in a blue moon, phone chargers, lights, and other smallish stuff. So, I can bump down to a 2000 watt I think and be fine. Whether I need a true sine-wave, I dunno, but it would be nice to have just in case.

    The space I plan to put it in is in my custom center console. The console isn't vented, but there's a good bit of open airspace for it to radiate into and I can stick a fan in there to keep the air moving. I'd also remove a top cover section if I knew I was pushing the inverter hard. I think I can deal with heat generated.

    Unfortunately, there are no costcos within 500 miles or more of me, so that's out of the option. I do have Sams however. I'll check them out.

    Here's a pic of the console the inverter's going in; the inverter will go under the rear storage compartment section:

  6. The Heater

    The Heater Rockstar 100 Posts

    Yamaha makes a very good (excellent in fact) 3000 watt portable generator that has handles on each end and small castors or wheels. It weighs about 75 lbs with fuel. For a camper this would work well. It could power an air conditioner if you don't have other heavy loads on it at the same time. I have their 2000 watt model and it works great for my purposes.

    Moogvo, I don't run a microwave because I don't want to bring it with me. But if I did it would be the most power hungry electrical item in my trailer. I try to camp with as few conveniences as possible. I would probably run it off my generator. I use an MSR Whisperlite and a Coleman stove to heat coffee.

    Crawdaddy, not all inverters are built with internal fans. With your set up you need to buy one with fans in it and make sure you vent at both ends of the air flow.

    I have a client who is an expert in auto electric (he has owned a business in this area for over 25 years). He likes Xantrex inverters. You will not find them for sale in box stores, however. He prefers these for replacement in motor homes and other RVs.
    Last edited: Apr 26, 2012

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