Electric System

[jaysdream]

I have a 35ft 1963 Owens Grandfisher. I have 2 12volt running all ships 12vlt stuff and starting my 2 - 350 Chryslers. <br /><br />I would like to add more (3 or 4) 12 vlt and a small generator and inverter running from my batt charger so I can run 110vlt stuff (Lights fridge coffeemaker toaster oven) <br /><br />We will spend 2 or three days over at Catalina Island and need the power for those days while moored. <br /><br />I want to run the current 2 12vlt just for starting – the others running through an inverter to run the appliances. When they get run down, run a small generator 1800 or 2000 watt so I can use my current Batt charger to fill them back up during non-peak times.<br /><br />Does this sound like a good plan?

 

[Richard Petersen]

Re: Electric System

I don't mean to hurt you feelings. BUUT. If you have to ask . Do not start to wire up a boat the size of yours. Get someone who can do this so a storm tossing the boat around does not flame out. Or start a fire where the 120 vac wires are pulled thru the boat. This is serious modifications.

 

[jaysdream]

Re: Electric System

Thanks - yes it will most certainly b done by a pro - just want to explore options - get some info before some guy charging me $$ says Oh yea, this is what you need -0 and me nt knowing a single thing.

 

[waterone1@aol.com]

Re: Electric System

This issue gets debated fairly often. I personally will not run any kind of generator that is not a marine approved unit. Other people have used the Honda portable units with success. Everything you mentioned above about running lights and small appliances from an inverter is do-able...untill you get to the toaster oven. That thing will most likely draw 12 amps or more on 120 volt, that translates to 120 amps at 12 volt....that is a-lot. My suggestion would be to install a permanent mount marine genset such as a Kohler 6 KW. Run your heavy draw items from the genset.

 

[18rabbit]

Re: Electric System

A few thoughts:<br /><br />(1) Do some reading. You need to estimate your max current draw to appropriately size the inverter. You’re probably looking at something in around the 2.5kw (or +) size. Start here, with the inverter, and work backward from there. Also consider the invert type, modified sine wave vs true sine wave. Powerboat Reports did an evaluation of 6 inverters (1.8 – 2.6kw) last April. Let me know and I’ll post a summery. More on inverters below.<br /><br />(2) You’ll need a house battery bank to support the inverter. If you will be doing this frequently, higher-end batteries are a better value. They cost more initially, but last longer, resulting a greater return for the dollar. It is possible to do what you are thinking of without the need for generator/genset if you have a big enough house bank.<br /><br />(3) Alternator: getting a bigger and/or second alternator (100amps or +) allows you dump a lot of power back into the house bank in a short time by running your boat’s engine. This can make up the difference of kw/hrs that are needed for that 3-day weekend.<br /><br />(4) You also might want to consider this: http://www.meps.com I like this idea but I would have to get creative with pulley sizes between the jack extension on the engine and the generator to get the required 4500rmps at ideal. Also, they’re not cheap!<br /><br />(5) Also know that starting Jan this year, the EU, the EPA, and the IMO (Int’l Maritime Org) are looking at controlling genset emissions. Don’t know if/when changes will come down the line, what they are looking to accomplish, and how (if?) it will impact existing gensets. My understanding is better combustion was already mandated and implemented in some gensets, so you may want to research this before buying.<br /><br />(6) Note: you can/should be running house lights off your house bank battery, not the inverter. You get better return for dc discharge with dc house lights. Also consider replacing existing 12vdc (24vdc) incandescent house lamps/bulbs with newer LED bulbs that use a lot less energy, and will likely outlive you…get them on ebay.<br /><br />(1.5) Definitely start by figuring out what size inverter you will need based on the anticipated max ac current you will need at any given time. Most inverter also function as a battery charger for the house battery bank, too. Some inverters have power sharing technology that allows any incoming ac to go to the house on demand; the rest of the ac (if any) goes into charging the house battery bank.<br /><br />Edit: Oh, and welcome to the board! <br /><br />Do you set in at Avalon or Two Harbours or ?<br /><br />Btw, most marine refrigerators run on ac if available, otherwise they take dc from the house bank.

 

[Richard Petersen]

Re: Electric System

Your Wattage is big. A bank of batteries to run the inverter and it's losses and the losses due to a non pure sinewave are putting your battery bank into a load of BIG & HEAVY golf cart batteries. They are not maintanance free and at 6 volts each, 20 are needed =1,200pounds. at 25 amps cont. they will last 383 min. charging will be different and 3 hours at 80 amps at 120 vdc.---------------------------- The 1,200# and the explosive gas of Hydrogen are what make a constant speed 60 cycle gas-diesel or whatever MARINE generator the only pratical course. Smaller, lighter, safer and about the same price when either way is completed.-------------Bite the bullit and size it for a large 120 vac window AC unit. Shore power on the boat. Get a unit that uses the same fuel as your main engines. You will laugh at the heat and humidity. 3 to 4 KW should do so you can run everything at once and not trip out.

 

[jaysdream]

Re: Electric System

[Thanks for all the great feedback <br /><br />this has helped me very much.