Wagan 400-Watt Power Dome EX – Power Inverter Test One — 26 Comments

  1. 10 minutes ago, my doorbell rang and the UPS guy dropped off my PowerDome EX. I hate that I didn’t know about the link, and I would have linked to it through you. However, I have plans to buy a second one (this one is for my wife, the second one will be for my truck). It’s still in the box…getting it out now!!!

  2. Jack, thanks for the video. A good way to test this unit or any battery back up is to plug in a 100watt lightbulb and clock the runtime. That way it’s easy to do the math on other electrical items that you are trying to run. I know it’s a 400watt inverter, so you couldn’t plug a hair dryer in there!

    I own one of these units and have it charging off the cigarette lighter in my truck at all times. We use it to inflate air mattresses and charge cell phones when camping. Also the air compressor is great for bike tires and footballs, but really is maxed out when trying to inflate a car tire.

    It’s an excellent product for around $125. I’d love to see a higher quality unit available for $200-250 that had a lithium ion battery!

    Great job on the shows…

  3. The wattage from that fan has got to high. A laptop under 100watt, typically. Can you hook this up with a small, say 30-60watts worth of panels, and add some power to a primitive small cabin-like shelter?

  4. I have had one for a few years now. I carry it in my mountain running Jeep. The jump start feature works quite well.

  5. This is great! I hope you test the air compressor also. Is that simply for airing up tires or does it have the power to run tools? I am interested in how long to run the laptop and the modum. That was my thought because my cell phone died and my power went out at the same time. would have been nice to email family to let them know i was ok.

  6. This unit is very impressively featured for its price point. Incredibly so, in the true sense of the word, meaning that the components have to be absolute rock bottom in quality to sell so cheaply. But with all the features I would consider getting one, knowing that it might not last long, even though I have a nice inverter that costs more than this versatile Wagan unit. I have a couple of specific caveats that I think are worth knowing/considering.

    It uses a lead-acid battery, probably an SLA similar (or identical) to the battery used in a computer UPS (uninterruptable power supply). Lead-acid means poor performance in cold weather, and if you’ve owned a motorcycle you know it means that its useful life is drastically reduced if you leave it out in the cold all winter. If you’re experienced with jump-starting autos from other autos, you know that frequently the donor battery is not enough — even a large auto battery — you also need the donor vehicle to be running before you have enough power to get the dead vehicle started, and sometimes you even have to let the dead battery charge from the running alternator for a while before it will go. I wouldn’t put much faith in this little 5-10AH battery to revive a dead vehicle, especially in cold weather. But of course, it’s better than nothing.

    The inverter in the Wagan is undoubtedly of the “modified sine wave” variety, meaning that it simulates an AC sine wave through a series of processor-generated square waves. All the cheap (sub-$125) inverters (like the Black&Decker you’ll find at Wally World) use this scheme because it is a CHEAP way to produce fake AC. This is a dirty power source that I would be uncomfortable powering sensitive equipment with because of my experience with them. Perhaps laptops don’t care, but I’ve had audio equipment express displeasure with the fake AC. I carry an AIMS inverter that produces a pure sine wave that is as clean as or even better than the AC from the power company. If an inverter is a pure sine wave model, it will say so on the packaging because it is a big selling point and they went to a lot of trouble to make it that way! The downside is that they are expensive — you can find them for around $135 if you look hard, but as Jack says, it’s only expensive once.

    Oh, and that old computer UPS that died and you haven’t been able to throw away yet? Put a new battery in it for ~$35 (they abound on the www), and you have a good AC power backup in your home for many uses other than computers. It’s a natural prep tool.

    Thanks, Doug

  7. If you’re unfamiliar with the Kill A Watt electricity usage monitor, check it out online. It’s a very useful and educational tool for under $25. Plug it in between an outlet and just about any appliance and you can see the power consumed and even monitor power usage over time (useful for something like a refrigerator that cycles on and off). It’s very useful for calculating how long a battery backup will power certain items or combinations of items. The reason I’m bringing it up here is that I’ve found it will not work correctly when used downstream of a modified-sine-wave inverter like the Wagan power cube or other cheap inverters. So use it to measure an appliance’s power consumption from a clean source, not with a cheap inverter.

    Oh, and here’s a bit about pure sine wave from the Wagan site (they do make PSW inverters): “The electronic appliances run cleaner, cooler, and quieter when running on pure sine power. As a result, pure sine inverters save energy costs and extend the life of appliances.”

  8. My wife uses a 110v AC breathing machine at night while she sleeps. I wonder if/how long this will run the machine?

  9. Provide the wattage of the machine and I could make an educated guess. But do a www search for “CPAP pure sine wave” (quotes unnecessary) and you’ll find information about some CPAP equipment requiring a pure sine wave. I believe, but don’t know for sure, that this would rule out the Wagan power dome.

  10. BTW — and sorry to dominate this thread — I see through a CPAP source that my AIMS inverter is available for as low as $109. It’s come down in price, I’m pleased to see.

  11. The laptop probably uses 50 watts, fan probably 65 watts or so. A device like this is cool, but has the same battery life issues. If you use it often the battery life will be shortened.
    I have a 1000w pure sine wave inverter connected to the 12v battery of my Prius. It will run my refrigerator, a fan for my wood stove, lights, etc.
    It will run for many days because the Prius will charge the 12v battery from its 230v traction battery, and when that gets low it will start itself and idle until it’s charged. It burns cleaner and quieter than any generator, and I don’t need a separate generator. It would work great for a remote cabin too.

  12. OK my wife’s breathing machine is a:
    REMaster Plus
    M Series

    The blower/boiler unit says:
    50/60 Hz
    1.70 Amp

    The power brick says:
    50/60 Hz
    2.50 Amp

    I am guessing you got to add the amerage?

  13. Dean – my wife has a Prius.

    Perhaps in a SHTF she sould just plug our inverter and her breathing machine in the car and sleep in the front seat with the AC on.

    All kidding assisde – is you inverter wired into the little motorcycle battery in the trunk and have you ran the inverter any extended period of time? I am wondering if all th juice thru the little battery in the back would kill it.

    I ran an extra cigarette lighter plug off my Prius/motorcycle battery to run the kids Nintendos in the back seat – the prius lacks back seat 12v plugs.. anyway a cell phone pluged into the little battery killed it in the airprot parking lot while we were on vacation for a week; however, the car was turned off – Embarasing.

    I am probibaly the only person in history that needed to jump start an electric car!!

  14. OK Tom, since you’ve provided amps, we don’t need to derive amps from a wattage rating (watts = amps x volts). Both units together = 4.2A (1.70 + 2.5), if they really draw that much in a steady state (they well may not, that could be a startup or otherwise max current). If I’m right about the Wagan battery being a common 5AH (amp-hour) battery, that means that it will theoretically run a 5A load for one hour. If your load is 4.2A, 5/4.2 = 1.2 hours of running time. If the Wagan has a 10AH battery, then the run time would be double that (2.4 hours). Not so good, huh. Back to our W=VA formula, 4.2A x 110V = 462 watts. I doubt your CPAP really draws that much, but I’m totally unfamiliar with what they do other than blow low pressure air. With a Kill A Watt you could find out exactly what the total power usage is.

    An 80AH automotive battery would run a 4.2A load for ~19 hours (80/4.2 = 19). Now that’s starting to sound quite feasible. Hope this helps.

  15. Tom, in my late night reply I was focused on the Wagan’s battery and failed to consider the wattage rating of the Wagan’s inverter which is 400W. Obviously if your wife’s CPAP really draws over 400W, the Wagan won’t be up to it. I would be reluctant to try to draw more than 3/4 of a cheap inverter’s rated output on a continual basis, or 300W with the Wagan. I like the more honest rating of the AIMS unit I have — 600W peak, 300W continuous. I have no problem drawing a continuous 300W with an rating like that. Of course inverters are available that would easily power your CPAP, as Dean has indicated (Dean, your Prius rig sounds fabulous!)

  16. One more post on this and I’ll try to go away… I’m feeling insecure about dissing the jump start potential of the Wagan power dome after Jack and Jeff both say it works well. 600 cranking amps is a significant capability if true, and given the size of battery that could realistically be contained inside the unit, that would seem to defy the laws of physics (not to mention economics). Perhaps this is a very short-term capability, levered by big capacitors or something? Still strikes me as in defiance of the laws of physics (would seem to require quite a large capacitor), but I’m wide open to being enlightened to the fact that they’ve really pulled this off somehow.

  17. Jack,

    Was Wondering, why couldn’t you set up a Solar Panel and hook it to a Lighter plug and “charge” the unit while your using it in a “real” emergency.

    The Idea of being able to charge things like the IPHONE, or small music devices, etc when needed can REALLY make what could be a disaster a non event.


  18. @Doug,

    Well the Dodge Truck which has a big V8 in it was dead, hooked it up, crank, start.

    The Jetta also has been around a while and we had a flat that since we have three vehicles took longer than it should have to get fixed. It sat for three weeks till I got around to changing it back to the fixed tire. (I know how wrong that is!). Key is the battery is 5 years old and sitting for that long it was dead, hooked up the wagan and vroom.

    All I can say is I have needed it twice to jump vehicles and have had no problems with it working. Actually on the Dodge the battery was so dead I took it to Walmart to get a battery and it would not even take a charge, so I jumped it again in the Walmart parking lot, drove to another store to do a wife commanded errand, jumped it again, then came home and replaced it. So in that case it was a fully dead battery and a pretty demanding motor.

    I tend to not get bogged down in doing math with items like this, I simply test them in real world scenarios and they either do or do not perform.

  19. @Michael as I keep saying this device is NOT a long term power back up solution. To me it is a damn good source of emergency radio, decent for lighting, very good for your vehicle (jump and compressor) and useful for short term use for some back up power.

    If you want sustainable back up power spend about 60-75 dollars a piece on two good deep cycle batteries. Get a good inverter (750 watts minimum) and a good solar panel/panel array in the neighborhood of 100-200 watts minimum. Top it off with a good charge controller and you are looking at 400-800 dollars depending on quality of components.

    Such a set up can be done in phases.

    Phase one – one battery, one battery charger and the inverter. (use this as true back up power and just keep it charged with the charger)

    Phase two – Small generator and 20 gallons of stabilized fuel. – Now you have generator power for direct use and you can charge the battery with the generator for “clean” and quite power inside the home.

    Phase three – Second battery – simply increases back up. Honestly this could be phase two as it will cost less. To me phase three and two are personal choice.

    Phase four – Add a 200 watt panel. Price them you will find many 200ish watt panels are not much more than one 100 and all are a lot less than two 100s. You will also need a charge controller at this point. In some locations you will do better with a small wind turbine at this point.

    Now you can build from there adding about 200 watts per each battery. You are now to a point of having small scale solar for daily use. Wire in some 12 volt lights into the house and run them direct off the batteries. Much more effective than the inverter.

    This is also a point to look at a bigger more powerful generator. The wagan is fine for an hour here or there but it is again not a long term solution to your power redundancy plan, just a nice adjunct that can save your ass on the road as well.

  20. You should be able to squeeze more time out of a computer (or TV) by simply decreasing the screen brightness.
    A completely white display consumes more energy than a screen that varies in color & brightness. You can actually get immediate feedback on how your devices consume electricity by purchasing a “Kill A Watt” device — these are fantastic devices for sizing generators and generally understanding how your electronics consume electricity.

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  22. I have looked at various brands and models of this type of unit (with varying features.) My concern is that the ones I have seen have such a range of reviews, and more poor than I feel comfortable with. Hence, I am still waiting. I am pleased that Jack is doing his tests, as well as real world use. Information such as that is helpful.