Generator comparisons

[jje1960]

There is very much hair-splitting on this thread....  I just can't see how this is that big a decision frankly.  Consider the basic issues that apply, price, noise, requirement and expected proficiency.... If you need this generator (or inverter) to take care of low, med or heavy load, buy appropriately.  Electronics (TV, Satellite box, computer, phones, etc), keeping the on-board battery charged, furnace fan, even a small coffee maker, 1k inverter is plenty.  Microwave use, move to a 2k.  Aircon use  your going to heavy load, better plan on the largest inverter types or noisy contractor what-ever, however cheap home center special.  Any unit run 24/7 or what-ever time cycle will need maintenance, oil change, air filter, general cleaning.

Okay, real world experience (if anyone cares... not much science specifics here) we spend plenty of time off the grid in our RV, Nascar camping and travel to campgrounds.  We use a 1k Mitsubishi inverter, this provides 24/7 everything except microwave and aircon, PERIOD.  Oil change and air cleaner maintenance with two weeks of constant use.  Fuel, well about 1gal every 10-12hrs, depending upon amp draw, yes the higher the amp draw the harder the motor will work, hence the higher the fuel consumption.

When we intend to use the aircon or microwave, we switch to our Boliy 3600, this electric start unit will run the 15k aircon and everything else, common sense here... if the aircon was to compressor start at the same time as using the coffee maker at the same time as using the microwave at the same time as running the vacuum cleaner at the same time as TV, Satellite box, Stereo, 3 laptops plugged in... and anything else that draws amps.... your going to pop the breaker...  Fuel consumption... average with our 3.6k gen/inverter is like 2gal / every 5-14hrs, obviously depends on amp draw.

We actually take both with us on every trip, I enjoy not being caught without power if problems occur.

Bottom line with us, is that if you do not need air-con and microwave, 1k is plenty, uses about 2.5gal avg per/24hrs.  Still need to consider the noise, maintenance and quality, but I can say that we have had 4 generators over the years for the RV and house, change the oil, keep the air cleaner clean, run the fuel out of the bowl.... and they last a long time.

   

 

[vassock]

I'm already almost 100% sure that I will use a 1k generator. However, there are more expensive brands and less expensive brands. There are inverter generators that vary engine RPM and regular (cheaper) generators. There are very expensive efficient generators and less efficient, but cheaper ones. Different configurations require different hardware even if we know we are getting a 1k generator.

1 setup is to get a Yamaha 1k inverter with variable speeds and use that with no trailer batteries except a battery in a laptop and a UPS. A UPS with AVR and pure sine wave tech can run a PC for about an hour when the generator needs to be refueled/serviced. This is a no battery set up and the savings are made from not having any batteries to buy or maintain. However, the generator will need to be run often when even low power electronics are used and of course most of the time the geny will run at 10% power which is inefficient even with a variable RPM inverter. Plus the generator is pricy.

Another setup is to get a cheaper normal generator which always puts out maximum power and to capture all of that power with a charger/battery that requires precisely that output (900W rated). The charger would be run while electronics are being used and turned off as soon as the batteries have a good charge. The costs of the batteries drive this setup price up, but money is saved on the generator. It may be less efficient, but only by a bit because at rated output generators tend to be efficient anyway. It also won't be run for long periods of time or often since the batteries will provide the power 99% of the time when only a fraction of that 900W is needed.

This is why I wanted someone with some experience to help me choose a battery configuration and ideal charger that would draw the rated 900W when charging the batteries.

 

[Ernie n Tara]

As someone, I think Ned, noted you simply cannot ensure that you always draw a given power level, no matter how you go about it. This is particularly true if you have batteries and a quality converter. The charge rate, and therefore the power drawn will change with state of charge in the batteries. Also, the items you are using will change with time of day, current activities, etc.

Your best approach is to look at what is the standard setup and adapt it for your habits. It is a fact that using a generator is inefficient as compared to the grid and that will continue to be true.

Figure out your maximum, average, and low level usage; estimate hours per day for each and presume a number of generator hours. Any of the devices (converter, inverter, etc.) will probably have a maximum efficiency of around 90% so the approach should be to minimize their use.

This results in many people who boon dock having either one, two or more pairs of six-volt golf cart batteries, perhaps a 1,000 watt inverter, and a generator large enough to run at least one air conditioner (3,000W) or microwave, etc.

I doubt you are going to improve on this approach, no matter how convoluted you get with the calculation!

JM2C,

Ernie

 

[vassock]

Are there no batteries that can be charged at steady voltages? Then I might need to rethink my setup.

Under normal circumstances: 200 watt peak power usage. Usually it will be less. Occasionally, I'll use an 800W microwave for a few minutes per day. So a 1k generator will be fine for me.

I am just trying to figure out a good setup to give me some flexibility when the generator is off.

Also is it possible to charge batteries by connecting them directly to the generator? Kind of like a middle man between the generator's electrical outlet and the computer.

 

[Alfa38User]

Are there no batteries that can be charged at steady voltages? Then I might need to rethink my setup.

No!! It is not in the nature of the beast. Charging at a constant level is called "floating" and that takes place at a very low current once the batteries are fully charged and remain close to that. IMNSHO, You are trying to micro-engineer this whole thing way too much....

Large plants like the telephone companies plant I am familiar with operate in float mode that way but ...

(Yes, the telephone switching plant power supply  actually consists of batteries floated constantly by high output rectifiers which, in themselves, are capable of supplying the whole load, and thus do not draw down the batteries unless there is an electrical power failure, very unlike an RV converter and a couple of small batteries.)

 

[Larry N.]

...
(Yes, the telephone switching plant power supply  actually consists of batteries floated constantly by high output rectifiers which, in themselves, are capable of supplying the whole load, and thus do not draw down the batteries unless there is an electrical power failure, very unlike an RV converter and a couple of small batteries.)

Except when power outage tests have been run (or a real power outage). Then there is a heavy charging load, depending on how long the outage was. Granted that the diesels or turbines (with generators) usually take over after a short time, but I've seen periods quite a bit longer than switchover time with the diesels purposely not running.

So the principle is the same for RV and central office -- float until a heavier charge is needed, then it's vary the charge until back to float mode.

 

[Gary RV_Wizard]

You are making this way too complicated and for no real benefit. Don't worry about small differences in power loading.

 

[jje1960]

You are making this way too complicated and for no real benefit. Don't worry about small differences in power loading.

Got that right, from the start I've said this is a very strange post, almost 'weird' ... How much back n' forth does it take to understand getting a genset?  While this may be a bit harsh, this discussion has been a bit 'dumb' from the very beginning.  Sorry if this makes anyone uncomfortable, but .... it sounds just plain stupid.

 

[skirk55]

I work on all generators and Honda has the best life cycle and low noise. Some generator you can not get parts for. Most copy Honda! Pay more and you will get more than 10 years out of the piece. Do not run regular gas use high test it will run cooler and not destroy your carburetor. The oil in the generator is not forever oil change it. run the generator every few months. I charge $80.00 to re flash and unit. The maintenance is more important than the MFG. 

 

[Wolf Pack Fan]

I see a lot of very techical responses.  Some very good one's I might add.  We've got an Onan 7k on our mh and it's more than adequate for all of our needs.  We do want to get a Honda EU2000 though, before spring.  It' much quieter, can be located away from the campsite or tailgating site and it's more efficient than the Onan.  With the Onan we can run pretty much whatever we want to, which wouldn't be the case with the Honda.  A lot of times we just don't need 7000 watts available because we're only powering entertainment devices and the fridge.  We would also never consider going to sleep with the Onan running.  My decision to purchase the higher priced Honda over some of the Chinese made invertor generators is the same reason we own Honda, Toyota and Lexus vehicles.  They're built better, last longer and on the ocassion that they need repair, parts availability is better.  I also like that the Honda has slightly more displacment than the comparable Yamaha EF2000.  Here's a video of the Honda EU2000 with a load load test it speaks well on the Honda.

http://www.youtube.com/watch?feature=player_detailpage&v=2y4uN1qYfeA

 

[skirk55]

Honda will take care of all warranty and recalls. You can communicate with a human at Honda.  A Honda carburetor sells for anywhere from $20 to $80 but some mfg we cant even get parts to replace a carburetor.  The Chinese motor copy Honda but the casting and cheap metal used in them are just junk!