What are real world runtime figures with the small portable generators?

MontyYoung

I'm trying to decide between a yamaha EF1000is or the EF2000is, on paper the 1kw is just big enough for my AC charger needs running it at 85-87% of its 900kva rating. With it's 2.5L tank and claimed 12hr runtime at 1/4 load, i estimate (more a wild guess) it will run my charger for 3.5hrs at that output which is enough to do what I wan't and finish off the rest of the charging with solar. I would do this 2-3 times a week. My area has alot of clouds and not so much room for panels. So are the manufacturer listed runtimes even remotely what people get? What about when the genny ages?

Just looking for some numbers & suggestions to help me choose. 
thanks

wellbuilt

It’s all about the load , I use a Honda 2800 @12 hrs 1/4 load . 

 I charge at 2000watts and the unit runs for 7hrs +- 
 I think the number on the Honda are close . 

 I would get a 2000 watt unit , it will run slower and get a longer run time then stated .
 My Honda  2800 will eq battery’s at 5/600 watts and run 15hrs on a tank of fuel because I’m running below 1/4 load . 

 It’s nice to have some extra power to run loads , you can’t really run any thing with a 1000watt unit most tools need 2000 watts to run .
  I just run a hour a day I have sun and panels but I’m covered in snow all the time 

Marc Kurth

I have never measured the loads, but my Honda EU2000i uses between 1.1 and 1.4 US gallons to run two large refrigerators, a chest freezer, small LED lights, and phone chargers overnight. Last power outage used about 3 gallons total for a 17-hour power down period.

I bought it about 5-6 years ago to power my Xantrex Truecharge 2, 60 amp 12v charger.

Wheelman55

Monty...get an extended run time gas tank...they work really well for me.  Fewer worries and less hassle.

mike95490

1kw is not much of a generator.  What is the power factor of your charger ?   Discover that number BEFORE you get a generator.

Marc Kurth

His 900 kVA should account for power factor? (Note that is a question, not a statement)

softdown

Motors have start up surges that may be 3-5 times normal current. A 1000 is a toy with limited utility. 

Marc Kurth

softdown said:

.....................................................................................

..................................A 1000 is a toy with limited utility. 

Compared to my neighbors and their whole house gensets, my 2000 Honda is a toy also - but it serves my narrow requirements quite well. I do agree that a generator in the 2,000 watt to 4,000 watt range has a whole lot more utility, but he stated his need as 900kVA.

YES, I would (and did) spend the extra money to jump to the next size.

Marc

MontyYoung

Thanks all, my 50A charger's PF is 0.99 so that is where i got the 85-87% of 900kva figure. But yeah the 2000 is more the go, just a few cm longer and wider too.
I will have to look into the extended fuel tank option, never occured to me such an idea...
I personally dont think 1kw-2kw is a toy, unless its used heavily each week. Such a size is more than enough for a getaway cabin.

BB.

I assume that you are talking about 900 VA , not kVA (1,000x VA).

And to type more than anyone should... For smaller residential gensets, there maximum rating is typically both Watts and VA max (i.e, a 1,000 Watt genset is 1,000 VA max too).

Larger/commercial gensets seem to be available (typically?) rated at 0.80 (80%) power factor... Or (just using 10,000 as an example, could be 100,000 or even 1,000,000+ rated--Way more than most of us here will ever need/use):

• 10,000 Watts * 1/0.80 PF rating = 12,500 VA max = 12.5 kVA

And to be clear:

• Power = Volts * Current * Power Factor
• PF can range from 1.0 (running a filament light bulb/resistance heater) to 0.70 (typical induction motor) to 0.50 or less (such as the "modern" twisty fluorescents, and such bulbs).
• PF is also equal to Cosine of the Phase angle between Voltage and Current (AC math) = Cosine of 60 degrees = 0.5 = 50% PF

A really nice website/newsletter on Generators (including power factor):

http://www.screenlightandgrip.com/html/emailnewsletter_generators.html

Personally, I would suggest not running a residential genset at more than ~80% of Watts (or VA) rated load continuously:

• 1,000 Watt/VA * 0.80 = 800 Watts/VA max continuous loads
• 900 VA loads / 0.80 (Bill's fudge factor) = 1,125 Watt/VA rated genset suggested minimum

Normal loads (like refrigerators, washing machines, etc.) typically are highly variable loads. Perhaps a high starting/surge current and relatively low running current (fridge ~600 VA surge, ~120 Watt continuous load, possibly 500 Watt defrost heater).

Battery charging can be a very different kettle of fish... If you are at a 10% rate of charge and discharge to 40%, and plug the charger in... It can draw near 100% of rated load for 4-5 hours (tapering down as the battery nears full charge).

So, for many of us, charging batteries with a deeply cycled battery bank can draw many hours of max charger rated load... And run the risk of overheating the genset windings/tripping onboard circuit breaker. NEC type Breakers are generally rated to not trip below 80% of rated load, and will trip with 100%+ of rated load (could be minutes to hours).

The next size genset would probably be pretty nice (~2,000 Watt/VA rated). Especially for Inverter-Generators (which have relatively low surge current capability and can trip with even very short surge current starting spikes--Whereas a similar standard alternator genset would "ride through" such surges).

Ran my inlaws home with 2 Fridges, 1 freezer, and 1x fish pond water+air pump on something like a bit less than 3 gallons per day on a (now obsolete) EU2000i Honda (right at the limit--Had to run ECO Throttle off for first 24 hours until broken in--Otherwise a starting fridge would stall the genset).

Made up an external fuel pickup (used 5 gallon fuel cans) with a fuel cap+syphon hose. Ran great for 2-3 days (normal oil change).

The smaller Hondas are great because they have a fuel pump that can draw a (small) vacuum on the internal fuel tank. Install a vent+hose in the fuel cap, and it can draw directly from an external tank.

Not sure, but I think the new EU2200i uses a (slightly) larger fuel cap. Don't know if the various models of EU3000 genset can syphon fuel or if you need to connect directly to an internal fuel pump or not.

-Bill

BB.

I forgot to add, Power Factors in the 0.95 to 1.0 are in the "most efficient/perfect" range.

-Bill

stuartscanlon

Another option for a 2kw honda (or other) is a propane conversion. Genny will run near full load off of a 5gal propane tank for a day. Other benefits include much cleaner exhaust and just a bit more quiet.

Marc Kurth

stuartscanlon said:

Another option for a 2kw honda (or other) is a propane conversion. Genny will run near full load off of a 5gal propane tank for a day. Other benefits include much cleaner exhaust and just a bit more quiet.

Interesting perspective on the sound level. I would like to know more.

I have heard that propane requires the engine to run at a higher RPM for a given load. I am NOT saying that I have compared, only sharing what three people have told me based on their experience.

Dave Angelini

stuartscanlon is right except propane will not quite hit the max power (loads) of gasoline and he kind of stated that. As far as noise it would be hard to quantify. The Honda type i genset is amazing still after all of these years for silence in the forest.

Much better to have a properly sized solar system in the SW US and places like that. Better but probably not cheaper than a genset.

 Been over 10 years since we used a genset for anything except remote pole sawing in the forest here.

mike95490

Propane has less energy content per volume than gasoline or diesel.  So a generator is de-rated when running on propane. 8kw becomes 6.5kw output. 

mountainman

I've used a 2000 for three years now for charging batteries with a 55 iota very  bad pf.
Also run a 10000 btu window unit. Not both  at the same time.
Started out with a 1000 generator and it was over loaded so it's fuel consumption was more than the 2000. And the 1000 watt didn't even ' last a year.

mike_s

Propane won't hit full power. In my experience, it produces a less objectionable noise (more of a puff-puff than the pop-pop you get from gasoline).

It's pretty easy to make an extended gas tank. Get a replacement gas cap for the genny - drill a hole in it and epoxy (both JBWeld and PC7 are fine with gasoline) a hose barb, then get some gas line which you then put into a larger tank. As gas is used, more gas will be sucked in.