Components on while charging?

67cj5

Man On a Mission
I have never heard of inverter gens doing this. Honda would have a class action lawsuit...
Yes neither had I until I told some guys what I was going to do regarding running my Fridges off of a Generator and then quite a few other folks pointed out that they too had made the same mistake and Companies like ENGEL warned many Customers what had caused the damage, But people need to know that If you let a Generator run out of Fuel it will send a Spike through your Fridge as it is just about to turn off because they Rev Up higher than their normal RPM Vs Voltage,

One thing I must put straight is that this issue is not just related to Honda, it applies to all Generator manufacturers So Honda is Not at Fault what So Ever.
 

67cj5

Man On a Mission
99.9% of generators are definitely not regulated. What you describe could be a problem with unregulated (or poorly regulated) generators.

I've never had a problem with this occurring with my Honda EU2000i generator. There is no switch for the automatic voltage regulation; if it's running, it's regulated 120VAC. It also regulates the engine rpm according to load while maintaining regulation, so an rpm surge isn't an issue. I've run a window AC unit with my generator until it ran out of fuel with no ill effects. Honda, Yamaha, and others are able to charge as much as they do for their inverter generators because they don't behave the same as their "equal" from Harbor Freight.
You have got it totally wrong, 99.9% of generators are regulated, Otherwise how on earth would the manage to keep their voltage constant,

Like I said DON'T take my word for it, You have been warned, Don't come crying when your fridge bites the dust and that company who made it refuses to fix it under warranty or hands you a huge repair bill,

Also before starting or STOPPING a Generator the Fridge MUST be switched OFF and When using the 12v Supply from a Generator there MUST be a Battery of Equal Voltage between the Fridge and the Generator.


Those of you who own an ARB who are in Doubt Read Page 4 regarding using your fridge from a Battery while using a High Speed/Powerful battery Charger, , also to NOTE is Never run your fridge from a Battery Chargers or an AC to DC Converter or a rectifier and also read Page 13 of your Manual.
 
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luthj

Engineer In Residence
Yeah, I searched for about 15 minutes on the web and can't find any references to this type of incident. There is nothing in the honda manuals about this type of event either. Honestly I don't think its possible for a quality inverter gen to do have a voltage spike like this. They safely handle the on/off current changes with an inductive load (AC unit for example). So the idea that they can't handle a 100W fridge, even during a fuel starvation seems ridiculous. Generators run out of fuel all the time.

Now cheap gens, like harbor freight direct-from-china specials? All bets are off. Regardless a single story from a friend of a friend doesn't form the basis of a blanket warning like this.

Older non-inverter gens aren't likely to surge like this either, as their heavy flywheels are designed to prevent rapid RPM changes.

The 12v supply may be a different story.
 

shade

Well-known member
You have got it totally wrong, 99.9% of generators are regulated, Otherwise how on earth would the manage to keep their voltage constant,

Like I said DON'T take my word for it, You have been warned, Don't come crying when your fridge bites the dust and that company who made it refuses to fix it under warranty or hands you a huge repair bill,

Also before starting or STOPPING a Generator the Fridge MUST be switched OFF and When using the 12v Supply from a Generator there MUST be a Battery of Equal Voltage between the Fridge and the Generator.


Those of you who own an ARB who are in Doubt Read Page 4 regarding using your fridge from a Battery while using a High Speed/Powerful battery Charger, , also to NOTE is Never run your fridge from a Battery Chargers or an AC to DC Converter or a rectifier and also read Page 13 of your Manual.
Of course there's some regulation going on. You'll note I said "unregulated (or poorly regulated)" in my response. Ignoring that indicates some problems on the receiving end. You keep lumping all generators together, when there's a clear difference between what's commonly referred to as unregulated & regulated output.

Your dire predictions don't concern me. As for the rest, that's not the same discussion as your All-Generators-Kill topic.

I don't know why you don't recognize the difference between a generator that outputs well-regulated 120VAC and whatever approximation of 120VAC is produced by a Harbor Freight special. Maybe looking over this gentleman's results will help.

Do you see a difference between the quality of the regulation between these two generators?
Which one do you think does a better job protecting sensitive devices?
Which one do you think costs more?

527393

527392

Here's another interesting photo.
527394

That's the unregulated 12VDC output of the same generator that provided the graph in the first photo. Even within the same generator, there's a significant difference between regulated & unregulated output.
 

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luthj

Engineer In Residence
Oh god, thats one nasty waveform... I am not really up to date on the portable fridge scene, but aren't most of them using universal ranging switching power supplies (like laptops and phone chargers)? Those are normally fine with up to 300V?
 

shade

Well-known member
Oh god, thats one nasty waveform... I am not really up to date on the portable fridge scene, but aren't most of them using universal ranging switching power supplies (like laptops and phone chargers)? Those are normally fine with up to 300V?
If you check that page, there are several questionable definitions of "regulated power". That was posted in 2005, but I don't think the market has changed much. If you want good power, you have to pay for it.

I can't speak to the power supplies on fridges, but the Danfoss manual has some information on page 9 that indicates it has some built-in protection for under/over voltage conditions.
 

67cj5

Man On a Mission
One of the main problems is as the RPM changes up and down and back up again as the fuel runs out The Hertz changes rapidly and it is this change that does the damage,, I personally never gave it a thought until other folks chirped in and told me about it on another forum, Until that point I was merrily going about my day without a care in the world, hence why I went and add some smart chargers to my list of Toys.

 

luthj

Engineer In Residence
Inverter gens won't have the HZ change with engine RPM. Older direct output types will change of course.
 

shade

Well-known member
One of the main problems is as the RPM changes up and down and back up again as the fuel runs out The Hertz changes rapidly and it is this change that does the damage,, I personally never gave it a thought until other folks chirped in and told me about it on another forum, Until that point I was merrily going about my day without a care in the world, hence why I went and add some smart chargers to my list of Toys.

Vince is right about using the AC side of a AC/DC generators to run a battery charger, as opposed to using the DC side tied directly to a 12V battery. I also wouldn't want to run a 12VDC fridge off of the unregulated DC output, especially if much cleaner power was available on the AC side.

I think the DC output on something like a Honda inverter generator is more of an afterthought, designed to be used in a pinch to charge a 12VDC battery if an AC charger isn't available.
 

67cj5

Man On a Mission
Vince is right about using the AC side of a AC/DC generators to run a battery charger, as opposed to using the DC side tied directly to a 12V battery. I also wouldn't want to run a 12VDC fridge off of the unregulated DC output, especially if much cleaner power was available on the AC side.

I think the DC output on something like a Honda inverter generator is more of an afterthought, designed to be used in a pinch to charge a 12VDC battery if an AC charger isn't available.
Yeah I agree, It's a worry because back when I was planning all this out I thought I had it figured but then when the topic of generators came up then things got put on the back burner for a while,

I have a big normal battery charger for charging my bank of batteries using either 240AC or the 240v outlet from a generator, but If I am going to charge them when the fridge is running then I will use the smart charger via a generator, Knowing my luck I am not prepared to take the chance of running my Fridge direct from the Generator regardless of the brand, I was going to go with a well known brand over here but now I am leaning towards the Honda but only to power my chargers or anything else except the fridge.
 

pugslyyy

Expedition Vehicle Engineer Guy
I'm just trying to figure out how a gasoline motor under constant load is going to run faster with less fuel.

Pretty much any modern generator is going to use an inverter so that they only need to run at the speed necessary to generate the required power, instead of running at constant rpm. The gensets I used at the army were old-school, you had to adjust the frequency manually after you started them - but we just used them to power a 400Hz inverter that all the sensitive electronics ran off of.
 

shade

Well-known member
Yeah I agree, It's a worry because back when I was planning all this out I thought I had it figured but then when the topic of generators came up then things got put on the back burner for a while,

I have a big normal battery charger for charging my bank of batteries using either 240AC or the 240v outlet from a generator, but If I am going to charge them when the fridge is running then I will use the smart charger via a generator, Knowing my luck I am not prepared to take the chance of running my Fridge direct from the Generator regardless of the brand, I was going to go with a well known brand over here but now I am leaning towards the Honda but only to power my chargers or anything else except the fridge.
There are probably are other brands of similar quality, but Honda and Yamaha both make great inverter generators that are reliable & quiet.

I've used my Honda to power construction equipment, a small air con unit, a full sized fridge, and my home's forced air, natural gas fired furnace when the mains went out. I wouldn't hesitate running anything directly off of the AC side.
 

shade

Well-known member
I'm just trying to figure out how a gasoline motor under constant load is going to run faster with less fuel.

Pretty much any modern generator is going to use an inverter so that they only need to run at the speed necessary to generate the required power, instead of running at constant rpm. The gensets I used at the army were old-school, you had to adjust the frequency manually after you started them - but we just used them to power a 400Hz inverter that all the sensitive electronics ran off of.
I don't know about faster, but an engine runs very uneven at the end. If that was tied directly to the power output, and something sensitive was on the receiving end, that could be bad. I think that scenario is what was concerning 67cj5, which could be a valid concern, but only if those conditions existed.

Washing that power through a battery before a sensitive device used it seems like a good idea, but a better idea would be to spend more on a generator in the first place.
 

luthj

Engineer In Residence
Some cheap/old gens have a slow governor. So if the fuel gets low in the carb bowl, the engine will starve briefly. The governor goes wide open to compensate. The carb then picks up fuel again briefly, and the RPM surge above normal. There are many generator designs, but on the crap ones, this can result in the output going outside the design range for some devices. If the gens fuel flow continues to be intermittent likely this, it can surge/up down for up to a minute. I had to look up some 25 year old gen designs to find one that way though. I would also argue that it sounds like some fridges AC input is an afterthought, an extra option cobbled onto an normally robust design. For example the Danfoss units can tolerate over 40v without damage. The solar danfoss controllers will run on 9-40V input!!!

This is not a problem for well designed generators though.
 
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Winterpeg

Member
My Honda eu2000i has an eco mode and cycles up if/when needed to a higher rpm. Wouldn't this be the same or similar to what is being described as being the end-game for devices?

It goes to my Noco Genius dual bank battery charger (2.5amp per bank) that charges my 2 deep cycle batteries.... which powers my ARB fridge.

I have ran it out of gas a couple times now and have had zero issues.... and have no concerns.
 
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