Large Inverter

[JK_Boston_Catalina310]

I posted this earlier on the Catalina 310 owners group. It was suggested by a wiser SOer that I might get more responses if I crossposted it at Ask All Sailors. So here it goes.

Hello all,

Looking any ideas for the installation of a full boat inverter. I had been going back and forth about weather a 2000 watt inverter or a Honda 2000 watt generator was the way to go to set our boat up for our long term cruise. After spending a couple of days in Edgartown on a mooring next to a power boat that ran their generator non-stop I have decided I can't be that guy.

So some basics:

1) the main reason I want a large inverter is to run items like power tools. Running things like the TV, laptop or microwave isn't really a concern bc we will either not have those items when we leave (like the microwave) or they are already 12 volt (like the TV and laptop charger). But I would like to be able to run a corded drill, dremel, saber saw etc. Being able to use the electric kettle to boil water for coffee would be nice too but I can always use the stove for that.

2) from my research so far it seems that pure sine wave is the way to go. Please tell me if I am mistaken because the cost of modified sine wave is so much cheaper.

3) I am open to an inverter/charger combo. My current charger is slightly under sized at 40 amp. But again cost seems to be a big factor here. Combos seem to be around $2K while a straight inverter can be under $1K. I don't necessarily need to upgrade my charger because it does the job and when we leave to go cruising we will be adding solar and on the hook almost all the time.

4) my primary battery bank consists of 4 6-volt golf cart batteries for a combined 460 Ah at 12 volts. I presume this will be large enough to run power tools for a short period of time without drawing the bank down too far based on looking at the specs. But some real world data is always helpful.

5) not running AC or anything like that. Don't have it and don't want it.

So if you have any suggestions on inverters or inverter/charger combos brands, ideas on where to install one or experience in using inverters of this size I would appreciate some replies.

I am currently leaning towards the Go Power 2000-watt pure sine wave inverter due to cost. But need to do more research on the brand. We have a Go Power 300-watt modified sine wave inverter on the boat now that was installed by the PO. Has worked fine but we don't use it very much.

Thanks and fair winds,

Jesse

 

[Bill Roosa]

couple of thoughts:
battery powered drills, saws....... don't need a big inverter. FWIW
I would recommend you inventory all the tools you would like to run and determine their wattage or amp draw (watts= 120*amps for AC appliances). use the biggest to size your inverter.
Alternately, since you don't want to be "that guy" and your power tool usage "at sea" is intermittent at best and a genset has some advantages over an inverter....... I'd not think this would be a "that guy" problem. Also the genset can charge you batteries in a pinch and would give some resiliency to your electrical system. always nice to have a backup way of getting the motor started.
If all you want to do is drive motors then a modified sine wave will work fine. Pure sine wave is mainly for electronics that don't like the "jerky" waveform. Not that modified sine wave will not work with electronics but I know my MW clock runs X2 speed when we have the inverter on. Still heats coffee great you just have to double the "cook time". your mileage may vary.

 

[redhead78]

I fried my old cheapo and got a Bravo 1600 watt inverter with 2 outlets, 2 usb ports, wf 800 watts continous, 1600 peak. Its nice and small has fans in it that only come on under load, I charge phones and its silent. Last week I plugged in a saber saw and trimmed a door and it worked perfectly. I bought on amazon for $76 I have been using it for 4 months, its perfect for my needs....Red

 

[Benny17441]

I can understand where sailors in MA may forego the usefulness of a gas powered generator but for us in the Gulf of Mexico is not an option. Power the air conditioner or die. The generator also runs our inboard charger to keep our batteries charged so that we can run refrigeration, use the inverter to run TV, microwave oven and coffee maker. With the generator the size of our battery bank is 210A. The downside is noise and fuel consumption but the benefits clearly outweigh our sensitivities to both.

 

[PKFK]

I have had a xantrex XM1800 for a couple years now and have had no problems.....runs the coffee percolator, toaster, microwave etc with no problems.

1800 watts continuous and 3600 surge (according to specs).

The bigger question is now are you planning on keeping the batteries charged ? You mentioned a genny - which is great - but depending on the overall power budget for the boat, you need to figure out if a genny, solar panels, or a big-ass (expensive) alternator/serpentine system is what you will use to keep the batteries fed to supply this inverter.

I suggest reading thru Maine sail's forum to get more info an opinions on how you will keep the batteries fed, in addition to deciding on which inverter to get.

Lots of fun, lots of choices, and lots of money !!

Paul

 

[mitiempo]

Agree with Bill you don't need a large inverter to run power tools. 1000 watts would be plenty.

Go Power inverters are good if sine wave but I am not impressed with their modified series in the small sizes. Their 300 watt sine wave is excellent.

If you want a combination with higher charging output then you have now I would look at the MS series from Magnum. 2000 watts/100 amp charging for example.

But keep in mind the only real difference is a bit quicker charging while plugged into shorepower. Your 40 amp charger is only a bit below the 10% of bank size many recommend. If at a marina overnight either the 40 amp you have or the 100 amp from a Magnum would end up at the same state of charge by morning as near the top the batteries accept less current.

I would get a 1000 watt sine wave inverter such as the Prowatt 900 from Xantrex - or a comparable from Go Power. I would not wire in to the panel but install it independently and use an extension cord from its outlet. This would power any tools you need and keep the costs down. I would spend the difference on solar - the only efficient way to fully charge the battery bank without noise or maintenance issues when away from shorepower.

 

[JK_Boston_Catalina310]

I can understand where sailors in MA may forego the usefulness of a gas powered generator but for us in the Gulf of Mexico is not an option. Power the air conditioner or die. The generator also runs our inboard charger to keep our batteries charged so that we can run refrigeration, use the inverter to run TV, microwave oven and coffee maker. With the generator the size of our battery bank is 210A. The downside is noise and fuel consumption but the benefits clearly outweigh our sensitivities to both.

Why not just have an appropriately sized battery bank and solar and not deal with the noise and fuel consumption?

We don't have AC and don't plan to add it before we head off to cruise the Bahamas and Caribbean. There are plenty of people who cruise in those areas, the Gulf of Mexico, the Sea of Cortez, etc. without AC. We don't feel the need for the added hassle of AC.

 

[JK_Boston_Catalina310]

Agree with Bill you don't need a large inverter to run power tools. 1000 watts would be plenty.

Go Power inverters are good if sine wave but I am not impressed with their modified series in the small sizes. Their 300 watt sine wave is excellent.

If you want a combination with higher charging output then you have now I would look at the MS series from Magnum. 2000 watts/100 amp charging for example.

But keep in mind the only real difference is a bit quicker charging while plugged into shorepower. Your 40 amp charger is only a bit below the 10% of bank size many recommend. If at a marina overnight either the 40 amp you have or the 100 amp from a Magnum would end up at the same state of charge by morning as near the top the batteries accept less current.

I would get a 1000 watt sine wave inverter such as the Prowatt 900 from Xantrex - or a comparable from Go Power. I would not wire in to the panel but install it independently and use an extension cord from its outlet. This would power any tools you need and keep the costs down. I would spend the difference on solar - the only efficient way to fully charge the battery bank without noise or maintenance issues when away from shorepower.

Yeah, that's kind of where I am sitting. I don't really need a bigger charger. This one seems to be handling the charge OK and doing equalizations without much problem.

Solar is on our list to add but probably won't happen until next year, right before we leave to go cruising. I am leaning towards some flexible Solbian panels, about 300 watts or so. The cost is just tough to take. But you do get what you pay for.

Why the extension cord over just tying it into the 120 volt system that exists already? From the installation instructions I have read it doesn't seem to be too difficult.

 

[Maine Sail]

Why the extension cord over just tying it into the 120 volt system that exists already? From the installation instructions I have read it doesn't seem to be too difficult.

Keep it simple!

Most of these inverters were never intended to be used as fixed installs to feed the AC system... A simple remote switch, fuse at the battery, and perhaps a single dedicated inverter only direct wired outlet is all you need.

If you go with an I/C then by all means tie it in... Also don't forget tools like heat guns which will require more than 900-1000 watts. For the price differnce of the transfer switch, and associated PITA wiring, you could have a ProWatt SW 2000... While I am not a big fan of the "X" brand these are a price point item that fills a good niche and have been pretty reliable for the "occasional" tool use category. We have the SW 2000 and I am constantly amazed at how often I load it up beyond 1000 watts....

I used our ProWatt SW just yesterday to heat shrink 15 2/0 & 4/0 battery lugs, nearly 20 minutes at 145A, after the owners batts crapped out on low voltage. I told him last year his batts were dead, they should not trip on low voltage after two shrinks, but they do............It was just easier to take the skiff over to our boat and do the shrinking...

 

[Bill Roosa]

Benny
you will not die without AC. did 20 years in the desert for Uncle Sam and I can attest that the first week is heck but you body gets used to it after that and it is not a problem at all. You do drink a LOT of water though.

I agree with MS KISS. If you do a complete install you have to get a transfer switch (read $$$$$) and then modify the panel so you can't run the water heater or AC circuits off the inverter by accident ...... real PITA and expensive. Most have a utility outlet on the box and extension cords are cheap.

 

[JK_Boston_Catalina310]

Keep it simple!

Most of these inverters were never intended to be used as fixed installs to feed the AC system... A simple remote switch, fuse at the battery, and perhaps a single dedicated inverter only direct wired outlet is all you need.

If you go with an I/C then by all means tie it in... Also don't forget tools like heat guns which will require more than 900-1000 watts. For the price differnce of the transfer switch, and associated PITA wiring, you could have a ProWatt SW 2000... While I am not a big fan of the "X" brand these are a price point item that fills a good niche and have been pretty reliable for the "occasional" tool use category. We have the SW 2000 and I am constantly amazed at how often I load it up beyond 1000 watts....

I used our ProWatt SW just yesterday to heat shrink 15 2/0 & 4/0 battery lugs, nearly 20 minutes at 145A, after the owners batts crapped out on low voltage. I told him last year his batts were dead, they should not trip on low voltage after two shrinks, but they do............It was just easier to take the skiff over to our boat and do the shrinking...

Thanks for the reply MS. I see what you mean about the price. Tough to not give that a thought at under $400. With the remote and wire I would be looking at $500. That's a good amount of savings to go towards my solar panels.

Hmm. Something to consider.

JK

 

[capta]

If you are going to use ac power more than a few minutes a day, then you should probably get the generator. We installed a 3kw inverter aboard (no real need for the pure sine wave, from my research, even my 110 vac refrigeration and air conditioning units work fine) and use it frequently, for short periods. But we also have a genset and 20 amps of solar aboard, to help keep up the batteries.
So, if it's an either/or situation, you would be best served with a portable generator, IMO, especially if you want to stay off the dock for a few days. Most not only supply 110vac, but a 12 volt tap for battery charging as well. Two birds, etc.....

 

[mitiempo]

...... a 12 volt tap for battery charging as well.

Pretty small DC output - only 8 amps on the Honda 2000.

 

[capta]

Pretty small DC output - only 8 amps on the Honda 2000.

Indeed, but at least one need not run a battery charger and all the available ac can be used where needed.

 

[mitiempo]

If the batteries are actually in need of a good charge the AC charger powered by the noise emitting generator is the way to do it. At 8 amps the generator would have to run all day and half the night to recharge a 440 AH bank of batteries if they were down a ways.

I am biased - I hate generators and would plan not to need one.

 

[capta]

If the batteries are actually in need of a good charge the AC charger powered by the noise emitting generator is the way to do it. At 8 amps the generator would have to run all day and half the night to recharge a 440 AH bank of batteries if they were down a ways.

I am biased - I hate generators and would plan not to need one.

A genset is a very handy lil thing to have around. We've just passed a thousand consecutive days without shore power and I must admit, our genset certainly does contribute to living aboard, versus camping aboard.
Anyway, from the OP's point of view, if he had a genset instead of an inverter, his batteries wouldn't be all that depleted, so the 8 amps should more than cover it, don't you think?

 

[Mark Maulden]

What I did on a previous boat wrt an inverter was to break the interconnect tabs on the 120V outlets that I wanted inverter power to and route some separate wiring to these isolated outlets. I didn't need inverter power to all outlets and didn't need shore power to all double outlets. No transfer switch etc..

 

[jsalley]

What I did on a previous boat wrt an inverter was to break the interconnect tabs on the 120V outlets that I wanted inverter power to and route some separate wiring to these isolated outlets. I didn't need inverter power to all outlets and didn't need shore power to all double outlets. No transfer switch etc..

That sounds like a great idea. Anyone know if it complies with ABYC standards?

 

[mitiempo]

A genset is a very handy lil thing to have around. We've just passed a thousand consecutive days without shore power and I must admit, our genset certainly does contribute to living aboard, versus camping aboard.
Anyway, from the OP's point of view, if he had a genset instead of an inverter, his batteries wouldn't be all that depleted, so the 8 amps should more than cover it, don't you think?

No I don't. A reasonable solar installation - say 2 100 watt panels - can produce more than 8 amps without any noise for 5 or 6 hours a day. If a generator was to be used powering a 40 amp charger makes more sense than the 8 amp gen DC tap. If the batteries are down a bit it would take 5 hours of generator time to equal one hour of AC charger powered by the gen.

He has a 30' boat not a 53' boat and his planned inverter use is pretty light. Hardly a reason to carry a generator and its fuel as well as its maintenance for occasional use.

I would install a smaller (under 1000 watts) inverter simply as described above and add a good solar system.

 

[mitiempo]

That sounds like a great idea. Anyone know if it complies with ABYC standards?

I don't think ABYC would have any issues with this. I would label the outlets as "shore" or "inverter" for convenience though.