Troubleshoothing help: Can't run appliances

[Derek Lumb]

Originally Posted by YoloSF

Fischer Panda genset's getting installed back on board next week, so I'll have that power. I just wanted to know the capabilities of the boat without the genset since I'd only like to run it as a back up if possible.

What's the difference between running the engine vs. the genset? Should I get the same results?

You guys have been so helpful so far, thank you so much for being so patient with me!

There are two problems using the main engine for power generation alone. First it will be lightly loaded, 2kW is equivalent to <3HP so on a yacht with a 40Hp engine it is less than 10%loaded. This can lead to bore glazing with significantly increased oil consumption and shortening of engine life.

Secondly, a parallel thread is talking about running cost for the main engine and is coming up with figures of $6/hr excluding the depreciation on the engine which is likley too add at least another $2/hr.

Conclusion - use the genset.

[Stu Jackson]

You want some information on electrical systems, try this:

Electrical Systems 101 Electrical Systems 101

It also includes a post on books to read.

[Ex-Calif]

Getting back to the heating problem...

Once you get knowledgeable about the energy budget you can limit the time you use a space heater - i.e. Use it an hour at night to knock the chill off the salon. Still wearing sweaters and such as you can't expect a toasty salon on batteries alone.

Then you might consider something to knock the chill off the berths.

http://www.amazon.com/Schumacher-122...ctric+blankets

This 12V blanket reportedly uses 4 amps so a couple of hours maybe be doable.

[YoloSF]

Originally Posted by Ex-Calif

Getting back to the heating problem...

Once you get knowledgeable about the energy budget you can limit the time you use a space heater - i.e. Use it an hour at night to knock the chill off the salon. Still wearing sweaters and such as you can't expect a toasty salon on batteries alone.

Then you might consider something to knock the chill off the berths.

http://www.amazon.com/Schumacher-122...ctric+blankets

This 12V blanket reportedly uses 4 amps so a couple of hours maybe be doable.

I ended up buying one of these: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Once in bed it's pretty easy to stay warm

[Ex-Calif]

Originally Posted by YoloSF

I ended up buying one of these: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Once in bed it's pretty easy to stay warm

Be careful. As a kid we had kerosene heaters that looked very similar. Bedshhets flopped into it one night and burned the bedroom down. My brother and I were lucky. Also the aforementioned carbon monoxide issue.

I wouldn't run one unattended - i.e. sleeping - but I'm a chicken. Also be cautious where you store spare propane.

[Stu Jackson]

Originally Posted by YoloSF

I ended up buying one of these: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Once in bed it's pretty easy to stay warm

Ex-Calif is right. Since it sounds like you're new to all of this, PLEASE whenever you use it beware that you need ventilation.

It sounds counter-intuitive, right? Why would I want to air the boat out when I'm trying to heat it? I'll lock the boat up tight.

Wrong.

You need ventilation.

When I run our trawler lamp and the catalytic heater, I crack the hatch over the companionway. We also have dorades.

Do some of your own research on boat ventilation and heating systems to find out why.

Hope it works for you.

I also close off the V berth, the head and the aft cabin doors to heat just the saloon. Works just fine.

[mitiempo]

As far as the electric heaters are concerned there is one thing nobody has mentioned.

You have a battery bank of 690 AH - 230 x 3. That is measured on a 20 hour rate, meaning you have 690 AH only at a usage of 34.5 amps. If you use only 20 amps your bank is much larger. But if using the 150 amps it takes to power a 1500 watt heater through an inverter you will only effectively have a battery bank of a much smaller size - somewhere around 450 to 550 AH at a guess. You would reach the low voltage cutoff point of the inverter very quickly.

Also, engine charging is only effective until the batteries reach 80 - 85% capacity. No matter how large the alternator the last 15% or so to a full charge will take 6 to 8 hours as the batteries internal resistance increases and they accept less and less current. Solar can make up the difference if you have a large enough array and the sun is shining.

This is why water heaters, any kind of room heater, or air conditioners should not be run off of 12 volts and an inverter with very few exceptions.