What Size and Type of Honda Generator ?

fundseeker

I'm hoping to get some advice on what size and whether to go with an inverter or regular style Honda generator for use with this off grid spring/summer/fall Canadian seasonal island cottage. I've been reading the Chris Olson and some other posts.

The system has :

• 2014 Magnum
• MS2812 inverter ,
• Outback Charge Controller ,
• 14 - 6 V , 220 amp Hr batteries ,
• 4 - unknown size PV panels ( likely 180+ watts )

The system provides power for an AC frig/freezer ( 6.5 amp , on defrost) , a 12 volt on demand water pump, lights , microwave etc. Thanks for your input.

BB.

Welcome to the forum Fundseeker.

Just to clarify... What is a "2014 Magnum"?

And, are you happy with how the system is running so far? 14x 6 volt batteries in a 12 volt battery bank is a bit on the difficult side to work with. I personally do not suggest that many parallel strings of batteries--And pulling ~1,200 to 2,000 watts from a 12 volt battery bank is about the maximum practical (or you have to use some very large diameter copper cable/bus bars to mange the 12 volt AC inverter current, and charging current):

• 2,800 Watt inverter * 1/0.85 inverter eff * 1/10.5 volts minimum inverter voltage = ~314 amps at 2,800 Watts @ 12 VDC battery bus

For charging, you would want around 5% to 20% (typically) rate of charge--And specifically for a genset people tend to run around 10% to 20% rate of charge:

• 7 * 220 AH battery strings * 14.5 volts charging * 1/0.80 typical AC to DC charging eff * 0.10 rate of charge = 2,233 VA rated input power to typical charger
• 7 * 220 AH battery strings * 14.5 volts charging * 1/0.80 typical AC to DC charging eff * 0.20 rate of charge = 4,466 VA rated input power to typical charger

And for a typical genset, you should be looking at ~80% of rated output max continuous:

• 2,233 VA / 0.80 = 2,791 VA minimum rated genset
• 4,466 VA / 0.80 = 5,583 VA minimum rated genset

An MS2812 will take around 15 amps @ 120 VAC input current:

• 15 amps * 1/0.80 genset derating = 18.75 amp rated geset
• 18.75 amps * 120 VAC = 2,250 VA rated minimium genset

So, if you limit your AC Charger to the MS2812 inverter, I would be suggesting a genset in the ~2,250 to 4,500 VA rated range.

And do you need a 120 VAC or a 120/240 VAC split phase output genset?

Gasoline/propane/diesel? If very cold weather use, gasoline may be the better option?

Your thoughts?

-Bill

Dave Angelini

BB. wrote: »

Welcome to the forum Fundseeker.

Just to clarify... What is a "2014 Magnum"?



-Bill

Champagne ? Sorry had to!

Apples

Good Lowrd... fourteen? 6V batteries? That sounds odd...

Anyhoo...

Hey, if your system is wired correctly and with BIG enough wire, your charge controller's charge profile voltage setpoints are adjusted to what your battery manufacturer recommends, your panels never partially-shaded save for once during sunrise and once during sunset, you should never need a generator. Period...during the months you have described. I love motor racing; all disciplines; love the "music" but I cannot stand! to hear generators droning away in the wilderness. There's no excuse! for it. None whatsoever. Electricity has always been silent (save for your utilities' own powerplants).

Now that that is off my chest, I cannot argue with one who wishes to invest in an emergency, stand-by generator. What size? depends on what appliances you deem necessary to power during a very rare solar electric generating malfunction (bad charge controller or inverter failure)...

inetdog

Actually, a typical solar PV system will have trouble consistently charging a large battery array to 100% SOC and will absolutely not be capable of delivering power for a long enough period in one day to do an Equalize charge if (when) that is needed.
A generator is a necessity for winter off-grid use and can save a lot of damage to a battery bank if available on an as-needed basis during the summer months.

An inverter type generator can be very quiet, especially when delivering less than full load. If you have it inside an enclosure, your neighbors may not even hear it.

lkruper

I have been wondering about putting my 1600W inverter generator in an enclosure for that reason and also in the event I needed to when it was raining. However I was concerned that it might not get enough oxygen to operate if the enclosure filled up with exhaust. I do have an outhouse at the cabin that could be used. Do you think it would work with just the door open?

Apples

Do you think it would work with just the door open?

If there were enough wattage capacity to also plug in a 10" brushless fan! You just want enough circulation so that the gen isn't drawing in it's hot exhaust and engine cooling fan heat right back into itself... from one end to the other.

lkruper

Apples wrote: »

If there were enough wattage capacity to also plug in a 10" brushless fan! You just want enough circulation so that the gen isn't drawing in it's hot exhaust and engine cooling fan heat right back into itself... from one end to the other.

Yes, I will have capacity for that. Why a 10" brushless fan?

inetdog

Apples wrote: »

If there were enough wattage capacity to also plug in a 10" brushless fan! You just want enough circulation so that the gen isn't drawing in it's hot exhaust and engine cooling fan heat right back into itself... from one end to the other.

Just piping the exhaust (in a non-restrictive way!) to the outside will insure that the engine is drawing clean outside air.
Casually adding a length of pipe to the exhaust line without knowledge of what is involved can cause back pressure, overheating, and valve damage.

vtmaps

lkruper wrote: »

I do have an outhouse at the cabin that could be used. Do you think it would work with just the door open?

Yes, It will work. Put the generator right in the doorway so the exhaust is directed out. When the generator is operating it may vibrate and "walk around" a bit... make sure it can't fall out of the outhouse. It is very important that you not do something like this.

--vtMaps

lkruper

inetdog wrote: »

Just piping the exhaust (in a non-restrictive way!) to the outside will insure that the engine is drawing clean outside air.
Casually adding a length of pipe to the exhaust line without knowledge of what is involved can cause back pressure, overheating, and valve damage.

Do you know if anyone sells something to direct the exhaust from the small inverter generators like Yamaha and Honda?

lkruper

vtmaps wrote: »

Yes, It will work. Put the generator right in the doorway so the exhaust is directed out. When the generator is operating it may vibrate and "walk around" a bit... make sure it can't fall out of the outhouse. It is very important that you not do something like this.

--vtMaps

That picture is pretty funny. Don't worry, while the outhouse is fully functional, we have indoor plumbing too and won't be using it for its intended purpose during a power outage.

Apples

Hahaha.... funny stuff when you get down to it. Running a generator inside an outhouse... and the double meanings from "venting exhaust" and "using a fan" et al...

Anyhoo, I mentioned "10 inch brushless fan" because they seem commonly available (drug stores, office supply, etc) and while I would think they're a low amp draw appliance they seem to move a lot of air. I only specified it's size as an example. These are household fans in their own enclosures and wired with household plugs. Not a computer/muffin fan.

Not to put too fine a point on it.

lkruper

Apples wrote: »

Hahaha.... funny stuff when you get down to it. Running a generator inside an outhouse... and the double meanings from "venting exhaust" and "using a fan" et al...

Anyhoo, I mentioned "10 inch brushless fan" because they seem commonly available (drug stores, office supply, etc) and while I would think they're a low amp draw appliance they seem to move a lot of air. I only specified it's size as an example. These are household fans in their own enclosures and wired with household plugs. Not a computer/muffin fan.

Not to put too fine a point on it.

Thanks. I don't lose power too often, but I am sure I can find out if this works when I do my periodic drills to exercise my generator. The good thing about the location of the outhouse is that it is also close to the one location where I get a southern exposure between the trees and canyon for a potential solar panel. I am thinking about also housing a deep cycle battery in there as well. The outhouse can become my "energy" shed!

Apples

I am thinking about also housing a deep cycle battery in there as well.

Remember to keep the battery as close as possible to the solar charge controller to limit volt drop through any unnecessary wiring.

Glad everything else seems like it might work out for you!

lkruper

Apples wrote: »

Remember to keep the battery as close as possible to the solar charge controller to limit volt drop through any unnecessary wiring.

Glad everything else seems like it might work out for you!

Thank you very much for the good ideas.

westbranch

Search here for ChrisOlson with generator as key word, there are a few threads on gen enclosures, and venting heat..