Generator Juice

[Miriam C.]

Ditto, and thanks for mentioning it.

1. I can answer and be simi sure. The power at most campgrounds is coming in at 20 amps. It is 120ac volts (really only about 117 but who's counting anymore.) It is the same as your house.

Amps is the amount of electricity your appliance uses. All appliances, incuding your charger, will say how many amps it uses. Somewhere in this forum Cracker (Dale) actually measured how long his battery would last.

Edit: In my attempt to simplify I left out a step that may be useful to people who don't read boxes. To get watts to amps:
devide watts/by volts (120)=amps.

BTW your battery or the person who sold it to you will tell you how long it will last using how many amps for how long.

Wish I could answer the others but I don't have a generator.

Aunti M

[bdosborn]

1) When I plug into shore power at a campground, how much "power" am I getting (15 "somethings" or 60 "something elses" or 120 "whatzits") and HOW is the power measured?

You need to find out how many watts your battery charger is using because most generators are rated in watts. Or you can make an educated guess from the charger's output. If it has a 10A output, its consuming around 150W. A 15A plug is good for 1800W.

Here's how I figured the wattage:
Volts times current=watts.
12Vx10amps=120 watts going from the charger to the battery, but the charger wastes a little power in heat so figure 150W total.
It works for 120V too. 150W/120V=1.3 amps going from the plug into the charger. The higher the voltage, the less current it will draw so thats why there's less amps going in at 120V than coming out at 12V. But the power consumed is always the same, no matter what the voltage. Thats why they rate generators in watts. But, the bottomline is that the battery charger is a dinky little load compared to typical generator sizes.

2) If I DON'T have access to shore power, but do have a generator, does my on-board battery charger "know" the difference?

Depends. Some generators have a very nice clean 120V power. Others don't. But, a battery charger isn't very picky about power so it probably doesn't matter what kind of generator you use, as long as it 120V.

3) Is there some magical formula that can be shared in layman's terms to size a generator to replace the outlet on a shore power pole so my battery charger CAN'T tell the difference between generator power and shore power?

No magic formula in this case other than picking one that is big enough. Since a battery charger is such a small load, about any generator over 1000W will power it. A 1000W generator is about the smallest size that is widely available. But, all bets are off if you try to power A/C or microwaves. Those are different animals and require larger generators.

4) Can it be so simple that a generator can be used intermittently to charge the teardrop's house batteries (through the on-board charger) so that boondocking would be limited to my supply of generator gasoline and not the size of the battery itself?

Yup. Oh and limited by the burly guy in the campground who doesn't like how loud your generator is.

Bruce

P.S. Be careful with your minn-kota battery charger when it comes to fluorescent lights. I killed one by turning on a fluorescent light when the battery was disconnected.
P.P.S. I have a 6 amp battery charger and my 1000w generator doesn't even break a sweat powering it..

[Miriam C.]

No magic formula in this case other than picking one that is big enough. Since a battery charger is such a small load, about any generator over 1000W will power it. But, all bets are off if you try to power A/C or microwaves. Those are different animals and require larger generators.

Just to give you an idea of strange power usage is, my drip coffee maker takes 1025 watts (pulls about 8.5 amps.) 1000 watt generator won't get it.
Oh yeah and the hair dryer

[bdosborn]

But a 1000w will power a blender, much to our enjoyment! Hmmm, I wonder how good a pickle juice margarita would be?
Bruce

[Miriam C.]

Ya know that don't sound half bad. Strangely unfair that you can watch tv, power blend an ice cold drink and charge a cell phone and I can't make coffee or dry my hair. But the margie sounds better right now.

Aunti

[Sonetpro]

I use a Kipor 1000 watt to do the same thing as your talking about. It has no problem running my 25 amp charger. It also runs a Small AC but that was carfully calculated. It also runs a Mr Coffee 4 cup coffee maker. But it won't run the AC and coffee maker at the same time. I've found we don't run the AC that much. We camp on the beach alot and usually at night there is a nice ocean breeze so it stays pretty cool. About the only time the AC is run is for a afternoon nap.
I've found that running the Genny in the morning for an hour or so when making coffee keeps the battery's charged. The Kipor is fairley quiet.

[mikeschn]

That setup looks sweet Steve. How much did that Kipor cost?

Mike...

[Sonetpro]

That setup looks sweet Steve. How much did that Kipor cost?

Mike...

ebay $350 shipping included. Man I love ebay.

[bdosborn]

That setup looks sweet Steve. How much did that Kipor cost?

Mike...

ebay $350 shipping included. Man I love ebay.

Yup, that's what I paid for mine too but I heard that Kipor raised their prices since
Bruce

[madjack]

Dan, the only problem I can see is that the power from the generator could be "dirty" that is to say that the sine wave produced is not nice and smooth but rather coverd in spikes...a lot of modern electronics do not play well with "dirty" electricity...this problem applies to generators as well as some invertors...many generators are now "digital" to insure a clean sinewave...generally they advertise themselves as being invertor equipped to give clean power........
madjack

p.s. here is a link from the KIPOR site that talks about "clean" power... http://www.kipor.com/prouducts_3.asp?parent_id=252

[asianflava]

My 2000 Kipor was $665 shipped.

[Miriam C.]

[Dan's quote]and still don't "get" the part about why the charger would care how many watts were coming "in" from a generator? [/quote]

Dan,
For anything you are doing you won't need to worry about it. If you look back at Bruce's first post you will find:

[Bruce's quote]Here's how I figured the wattage:
Volts times current=watts. (the current is rated in amps. mc)12Vx10amps=120 watts going from the charger to the battery, but the charger wastes a little power in heat so figure 150W total.
It works for 120V too. 150W/120V=1.3 amps going from the plug into the charger. The higher the voltage, the less current it will draw so thats why there's less amps going in at 120V than coming out at 12V. But the power consumed is always the same, no matter what the voltage. Thats why they rate generators in watts. But, the bottomline is that the battery charger is a dinky little load compared to typical generator sizes. [/quote]

The simple of it is if you didn't have enough watts your charger wouldn't get enough power to charge your battery.

[bdosborn]

Dan,

Sometimes its easier to think of electricity like water. Imagine you have a pump that's pumping water through a garden hose. You're spraying a windmill with the garden hose because you want to see the blades turn. The windmill won't turn if there's not enough water coming out hose or if the pressure is too low. Your battery charger (windmill) won't work if the generator (pump) isn't supplying the proper voltage (water pressure) and current (water volume). Wattage is just the voltage times the current.

Another analogy is that watts are proportional to horsepower (746 watts/HP). You need to make sure your generator has enough HP to run the battery charger.

Clear as mud?

Here's a link for more electrical stuff:
http://science.howstuffworks.com/question501.htm

Bruce

[mikeschn]

Thanks Guys...

Hmmm. Is the Kipor clean like the Honda or the Yahama?

Mike...

[madjack]

Kipor claims that their Ti models are as clean as it gets..............................
http://www.kipor.com/prouducts_3.asp?parent_id=252