inverter on a gb 32

[STG]

I need some advice on inverters. I know they convert DC to AC for small appliances but since batteries can run down quickly what's the real benefit of an inverter ?

 

[syjos]

AC available continuously without shorepower, generator, noise.

Inverters typically have more powerful chargers than stand alone battery chargers..

Hybrid inverters can add to shorepower and generator output by combining inverter AC output with AC from shore or generator.

The AC is not free. The battery supplying DC to the inverter must be replenished.

A large battery bank will provide AC for longer periods and accept higher charge rate for a longer period.

 

[SteveK]

Real benefit for us.
Toaster, coffee pot, microwave and most important blender, your list may vary. The things you want on your boat that do not run on 12 volt

 

[STG]

This help
Thx
and Happy New Year

 

[SoWhat]

Typically everything runs off 12V including the mini fridge which can run on either 12V or 120V. The fridge might draw 10A when the compressor starts but settle down to 3A while running. A microwave might draw 10A. A Keurig coffee maker might draw 10A while heating up. As long as you don't run them all at once a small inverter should be OK.
I have the inverter on the house battery so if it goes flat I can still start the engines. I also have a small Honda generator just in case. Haven't needed it yet.

 

[syjos]

Forgot the most important benefit - ability to run electric blanket on inverter when at anchor.

 

[SteveK]

Forgot the most important benefit - ability to run electric blanket on inverter when at anchor.

Thought about that, so far have not needed with diesel heater. But if I did I would go with 12V blanket. Mind you, any appliance I would have to buy I would consider 12V. The ones I have are hand me downs 110V from the house.
It is the loss of battery AH during conversion to be considered.

 

[STG]

So an inverter powers the modern conveniences and when the inverter runs only off battery then the batteries power level has to be watched.

Also the inverter can run off the generator and produce, convert generator to inverter power, for more stable power for the modern conveniences ?

 

[STG]

Watching the battery power level means generator needs to be used to periodically recharge batteries for continued inverter power ?

 

[STG]

Or the inverter can also run off generator.

 

[SteveK]

Or the inverter can also run off generator.

If you have an inverter/charger combo then genny can power the inverter to charge batteries while feeding AC to the panel same as shore power.
If you have a stand alone charger and stand alone inverter I would use AC from Genny not inverter, The standalone charger will feed off shore or genny

 

[High Wire]

With an inverter/charger, it turns to charger mode when shore power or generator are available. Swaps to inverter AC output when shore power and generator not available.

 

[STG]

Sounds like a smart device. I like it.

 

[syjos]

I find that 12 volt appliances, bulbs etc cost more than 110 appliances and bulbs and are not as readily available.

Additionally, 12 volt light dimmers are more expensive than 110 dimmers.

All convienence items and illumination on Sandpiper runs on AC except the refrigerator compressor and navigation lighting.

The inverter powers the whole AC panel except water heater, which is powered by a separate inverter output only energized by generator or shore power. We are not concerened by loss due to the inefficient aspect of battery depletion and charging.

We utilize the alternator or generator to recharge batteries. The generator is near silent and runs 4 to 6 hours per day at anchor. We don't practice electrical conservation.

 

[STG]

What kind and size generator is on Sandpiper ?

 

[syjos]

What kind and size generator is on Sandpiper ?

We recently installed a Westerbeke 5.5 kW diesel generator.

Previously had a Westerbeke 4.5 kW and an Entec 4200 generator.

 

[SoWhat]

Watching the battery power level means generator needs to be used to periodically recharge batteries for continued inverter power ?

There are many different solutions. I have twins and no room in ER for generator. I have to start an engine to charge battery or alternatively use my Honda eu2000. The batteries normally charge while running but if I'm at anchor for any length of time I run the engines. I have separate 120V charger for when I'm on shore power.

The separate inverter is only used at anchor. Having separate inverter and charger was a low cost solution for my tightly packed ER. The key is to have a good battery monitoring system.

 

[DDW]

.....

Also the inverter can run off the generator and produce, convert generator to inverter power, for more stable power for the modern conveniences ?

Small generator power isn't terrible (not as bad as a cheap square wave or "modified sine wave" converter) but isn't nearly as clean as power from the power company at home. Most household appliances and electronics are happy with it. But a good true sine wave inverter will produce cleaner power, cleaner even than the power company at home. If you have something really sensitive to that, it may be better to power from the inverter. Most stuff, makes no difference.

When thinking of generator vs. inverter, you have to get into the mindset of thinking about energy used. An inverter can produce a lot of power for a short time from batteries, or low power for a long time. So things like microwave oven usage (lots of power for <1 minute) or charging a cell phone (very little power for several hours) are OK, but running an air conditioner or heater (lots of power for a long time) are not a good match for an inverter.

 

[STG]

So I need to replace or rebuild my generator. Should I just take this opportunity to get a new generator that is a combo generator / inverter ? Or is there even such a thing as a combo unit.

 

[Iggy]

I am sure that most readers/members know this. But for others.........

I also say, you must do the math. What is your load in amps per hour, how many hours do you want to use it for, other loads, and how many amp hours is your house bank?

When converting DC into AC, thats a big load on the batteries. Some one mentioned a microwave. Just to keep numbers round, a 1200 watt microwave at 120v pulls 10 amps. Now pull that same wattage from 12v is 100 amps. Now add in your inverter loss, your in the range of 110amps from your house bank. Its a good sum of power.

 

[mvweebles]

So I need to replace or rebuild my generator. Should I just take this opportunity to get a new generator that is a combo generator / inverter ? Or is there even such a thing as a combo unit.

New generator will be expensive. You should have your current one diagnosed to understand why it's not operational.

First, a baseline. Generators only create AC power, 120vac in your case. . That's it. They burn some sort of hydrocarbon (diesel) and there is NO conversion to or from 12vdc. An inverter converts 12vdc to 120vac household power. That's it. They come in a variety of sizes from small 60 watt ones that plug into a cigarette lighter, up to hard-wired inverters that can power an entire house for solar power applications. A battery charger takes 120vac and converts to 12vdc to replenish (i.e. Charge) a battery. For boats, inverters are often combined with battery charger into a single appliance. A typical sized one on a boat your size would be around 2000 watt inverter with a 55-amp battery charger. Purchase price would be around $1000 with professional install costing around that much with cables and fusing. Right now, your boat already has a battery charger somewhere that operates when plugged into shore power or when generator is working. You also have an alternator on your engine that charges when you are underway, though depending on size of batteries, could take many hours to replenish a charge after a day or two at anchor.

Before you make any decisions on buying stuff, you really need to think about how you will use the boat and what problem you are trying to solve. If you have an electric stove, you need your generator. If you want air conditioning, you need your generator. Everything else can be run off your batteries, just depends on how long you can sustain the system. A GB 32 is a pretty small boat and most folks use these as a day-boat or occasional overnighter. That said, I once owned a Willard 30 and used to take her on extended trips of a few weeks.

If your boat runs entirely on 12vdc (fridge is 12vdc and stove is propane), then your only need for 120vac is likely to charge your PC or perhaps run a TV. This can be done with an inexpensive 300-watt inverter that plugs into a cigarette lighter. A microwave typically needs a 2000-watt inverter due to startup draw.

So you have to decide whether you want to just power individual loads such as charging your PC (inexpensive), or if you want all of your AC outlets to be powered while underway (an inverter charger - relatively expensive and more complex).

Sounds like the boat is new to you and you're just getting started in the wonderful world of boating. My gut-level recommendation is to figure out the generator repair, then do base minimum for an inverter and not go the full system-wide inverter/charger route until you've owned the boat for a while. Also, check your battery bank capacity and age of batteries.

Good luck and welcome aboard. Nice little boat.

Peter

 

[STG]

Peter thx. Yes I am new to trawler boating. I grew up boating and have had a 20’ pontoon for many years. The 32 GB will make it nicer for my wife and daughter to be out on the boat all day and perhaps some over nighters. We are on Mobile Bay so bottom fishing In the Gulf is also in the plans.

My idea was to do just as you mentioned. Repair the generator and decide what the total electrical needs will be. My boat, Maudy, has an electrical stove, Frig, windless, AC/Heat forward and also another in the Main Cabin. I’m sure I’ll get a micro but no coffee maker. We do cold water drip coffee. 4 bilge pumps and the regular set of instruments Navi depth radar vhf stereo. I’ll be doing the math and setting up a power source that fits my needs.

From all the comments Received I now have a much better idea of the inverter and the part it will play on Maudy. Thank you all very much.

My boats name Maudy is a family name. My great grand mother was Maud. She was the daughter of Capt John Tobin the owner of many steamboats on the Mississippi. She was a very lovely and strong willed woman. Her picture will be aboard. She was petite and vivacious, which I feel fits my GB 32 well.

Again thx to you all and have a very Happy New Year.

 

[FF]

"We are on Mobile Bay"

For much of the year a gen set for air cooling will be necessary .

The inverter will only be needed for short 5 min. use of 120v items like a blender, that you don't want to start the gen set for.

Most house 120v items are limited to a 15A plug and wiring , so an inverter of 15A would be all you should need.

 

[rwidman]

Or the inverter can also run off generator.

OK, an inverter converts (in this case) 12 volts DC to 120 volts AC. How, and more importantly why, could you and would you run an inverter of a generator?

 

[rwidman]

I need some advice on inverters. I know they convert DC to AC for small appliances but since batteries can run down quickly what's the real benefit of an inverter ?

The real benefit of an inverter is, you can use it to power appliances designed to operate on 120 volts AC (household power). Examples would be a microwave oven, a coffee maker, a toaster, hair dryer, etc.

To effectively use an inverter to power these things, you have to have a substantial battery bank. On my boat I have four 105 AH batteries as a house bank.

And of course, you need a way to recharge the batteries after using them. Cruising under power will usually do this, so will being plugged into a marina's shorepower for the night.

 

[syjos]

OK, an inverter converts (in this case) 12 volts DC to 120 volts AC. How, and more importantly why, could you and would you run an inverter of a generator?

To recharge batteries.

With hybrid inverters, the inverter can augment the generator during peak load. The inverter switches from charger to inverter, matches waveform and adds the inverters output to the generators output for short periods. Switch back to charger when demand drops.

 

[FF]

"why, could you and would you run an inverter of a generator?"

Probably not , the inverter uses batt power , the gen set gas or diesel.

For a few min of 120v , the inverter is great , few will have enough batt power to run for a half hour.

 

[AZ2Loop]

....Also, check your battery bank capacity and age of batteries.

Good luck and welcome aboard. Nice little boat.

Peter

STG, do not overlook Peter's comment above. Develop an understanding of your house battery bank's capacity. By capacity, think "usable" capacity, which varies across the different battery types (flooded lead acid, AGM, Lithium, etc.).

Your house bank's capacity is very important. The inverter is giving you nice, clean, 120v power for your appliances, but it is drawing that power from some finite source -- your house battery bank. Without an adequate battery bank from which to draw power, the nicest inverter is still useless. So, understand your power needs and how your house bank can meet them.
One extremely helpful resource would be Jeff Cote from Pacific Yacht Systems. His Youtube videos are very good for helping you understand your electrical system. You will find a video from him on almost every electrical need for your boat.

 

[rslifkin]

For a few min of 120v , the inverter is great , few will have enough batt power to run for a half hour.

All depends on what you want to run. Our ice maker runs 24/7 off the inverter when we're not on shore power, but we don't run big draws off it other than the toaster and coffee maker, both of which are only a few minutes.

 

[tdomenech]

I have a pure sinewave hybrid inverter on my boat. I, long ago, changed out the cold plate refrigeration for a regular LG refrigerator/freezer. Also, have tv's, fans, Nespresso coffeemaker, etc. !st, when running, I typically don't use my genset IF the weather is nice since I'm almost always alone going from point A to B (no need to have AC's running, etc.) so my inverter takes care of the fridge/freezer. Since my alternators are charging batteries, I'm good with that AC power. Before I got the pure sinewave inverter, my Nespresso would complain trying to work of modified sinewave....works perfectly now. Short. . . inverter is great and used A LOT! For instance, at night at anchor, nice weather, I just have fans on (again, fridge/freezer needs power) and, with my battery set up, I'm good through the night. Next morning, crank up and go on my way...letting engines charge batteries.