We're going to buy a petrol generator for use on our (fairly small)
boat, it will be for two main purposes:-

Recharging the main batteried when more than a day or two away
from mains electricity.

Running the electric oven/cooker (around 1.2kW).

The battery charging will be via the existing mains chargers so
there's no need for a 12v charger output from the generator. To cope
with the cooker load I think something around 1600 to 1700 watts
should suffice (probably 2kva).

Diesel would be wonderful but I suspect much more expensive and,
possibly, noiser too.

The generator will probably live outside[ish] but boxed in a metal
cabinet to protect it from the weather (and being nicked).

What recommendations do people have? Prices seem to range from around
£200/£250 up to as much as you want to spend. What do you get for
more money and are there any brands to be avoided and/or looked for?

--
Chris Green

On 10/02/2012 14:19, wrote:
We're going to buy a petrol generator for use on our (fairly small)
boat, it will be for two main purposes:-

Recharging the main batteried when more than a day or two away
from mains electricity.

Ok.

Running the electric oven/cooker (around 1.2kW).

Insane.

I know propane on boats needs a certain amount of care, but surely it's
the way forwards?

On 10/02/2012 14:19, wrote:
We're going to buy a petrol generator for use on our (fairly small)
boat, it will be for two main purposes:-

Recharging the main batteried when more than a day or two away
from mains electricity.

Running the electric oven/cooker (around 1.2kW).

The battery charging will be via the existing mains chargers so
there's no need for a 12v charger output from the generator. To cope
with the cooker load I think something around 1600 to 1700 watts
should suffice (probably 2kva).

Diesel would be wonderful but I suspect much more expensive and,
possibly, noiser too.

The generator will probably live outside[ish] but boxed in a metal
cabinet to protect it from the weather (and being nicked).

What recommendations do people have? Prices seem to range from around
£200/£250 up to as much as you want to spend. What do you get for
more money and are there any brands to be avoided and/or looked for?


What you get for more money is a quiet(ish) 4-stroke engine, better
reliability and a decent spike-free sine-wave mains output. If any of
these are important to you, have a look at Honda's inverter-based
jobbies. However, a 2kW model (which is what I've got, for providing
emergency essential domestic mains) will set you back about a grand. If
that's too much, have a look at the similar but cheaper ones offered by
Machine Mart. Their 2.2kW Clarke model is under £500.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Fri, 10 Feb 2012 14:19:28 +0000, wrote:

We're going to buy a petrol generator for use on our (fairly small)
boat, it will be for two main purposes:-



Diesel would be wonderful but I suspect much more expensive and,
possibly, noiser too.

The generator will probably live outside[ish] but boxed in a metal
cabinet to protect it from the weather (and being nicked).

Main thing to ensure that any spilt petrol or vapour from filling or a
leak or can be vented away safely. Petrol vapour is heavier than air
and can accumulate in bilges and other low down areas.
If enough accumulates and then gets ignited it usually ruins somebodys
day. I would stick with diesel for that reason.
Deisel used in a generator can be purchased at a lower duty rate as ll
which is also an advantage, and you can legally store more cans of it
if you have to purchase it and transport it to the boat.
This is a useful guide if you wish to use petrol.
http://www.boatsafetyscheme.com/down...dingPETROL.pdf

You don't indicate where you keep and what type of vessel it
is,sometimes the custodians of the water where you wish to use/keep it
have regulations that have to be complied with.

G.Harman

wrote:
[snip]

What recommendations do people have? Prices seem to range from around
£200/£250 up to as much as you want to spend. What do you get for
more money and are there any brands to be avoided and/or looked for?

For a boat you want a quiet generator and probably a suitcase design for
ease of lifting into and out of the cockpit. Given that you want to run a
1.2kW oven I'd suggest around 2-2.4kVA as you have stated.

Personally I would look for four stroke, key start and preferably remote
stop/start.

This item on eBay is the sort of thing I had on mind. I wouldn't fancy
paying £760 for one though.

300648629418

I've found Kipor generators to be good, if not as quiet as Honda. When I
bought mine it cost £450 for a 5kVA "silent" generator. The same unit would
cost me £ 1200 to replace. Modest 2.4kVA sets now cost around £500.

Don't get a frame type generator. The noise will drive you and anyone
within a km barking mad.

On 10/02/2012 19:10, Steve Firth wrote:
wrote:
[snip]

What recommendations do people have? Prices seem to range from around
£200/£250 up to as much as you want to spend. What do you get for
more money and are there any brands to be avoided and/or looked for?

For a boat you want a quiet generator and probably a suitcase design for
ease of lifting into and out of the cockpit. Given that you want to run a
1.2kW oven I'd suggest around 2-2.4kVA as you have stated.

Personally I would look for four stroke, key start and preferably remote
stop/start.

This item on eBay is the sort of thing I had on mind. I wouldn't fancy
paying £760 for one though.

300648629418

I've found Kipor generators to be good, if not as quiet as Honda. When I
bought mine it cost £450 for a 5kVA "silent" generator. The same unit would
cost me £ 1200 to replace. Modest 2.4kVA sets now cost around £500.

Don't get a frame type generator. The noise will drive you and anyone
within a km barking mad.
Another vote for Kipor (Honda clones)
I have one of their 3kVA ones which has been very reliable.

On Fri, 10 Feb 2012 14:19:28 +0000, wrote:

Recharging the main batteried when more than a day or two away
from mains electricity.

Don't they recharge from the engine?

Diesel would be wonderful but I suspect much more expensive and,
possibly, noiser too.

And heavier. I can *just* lift our 2kVA open frame diesel set, mind
you that would normally include 20l of diesel as well. And it is fing
noisy, we can park it with hefty solid stone walls in the way but it
still becomes wearing after a while.

The 2kVA inverter jobbies are good. If I'd had the dosh when getting
a generator I'd bought one and probably the conversion kit to
propane. I'm not keen on petrol, easy to slop and has tendancy to go
WOOF!

A diesel would mean you could siphon the main engines fuel tank.
Would you have paid full duty on that diesel though, I know the rules
were changing on red diesel and boats but don't know what happened.

--
Cheers
Dave.

On Feb 10, 2:19*pm, wrote:
We're going to buy a petrol generator for use on our (fairly small)
boat, it will be for two main purposes:-

* * Recharging the main batteried when more than a day or two away
* * from mains electricity.

* * Running the electric oven/cooker (around 1.2kW).

The battery charging will be via the existing mains chargers so
there's no need for a 12v charger output from the generator. *To cope
with the cooker load I think something around 1600 to 1700 watts
should suffice (probably 2kva).

Diesel would be wonderful but I suspect much more expensive and,
possibly, noiser too.

The generator will probably live outside[ish] but boxed in a metal
cabinet to protect it from the weather (and being nicked).

What recommendations do people have? *Prices seem to range from around
£200/£250 up to as much as you want to spend. *What do you get for
more money and are there any brands to be avoided and/or looked for?

For something very different there are Listeroids. Extremely long
lived and heavy.


NT

Clive George wrote:
On 10/02/2012 14:19, wrote:
We're going to buy a petrol generator for use on our (fairly small)
boat, it will be for two main purposes:-

Recharging the main batteried when more than a day or two away
from mains electricity.

Ok.

Running the electric oven/cooker (around 1.2kW).

Insane.

I know propane on boats needs a certain amount of care, but surely it's
the way forwards?

We have gas rings but a small combi microwave/grill/oven, much smaller
than anything similar (if there was such a thing) driven by gas. We
have enough battery capacity to run the microwave off the inverter for
the few minutes one usually runs the microwave but sometimes it's nice
to roast/grill things.

--
Chris Green

Roger Mills wrote:
On 10/02/2012 14:19, wrote:
We're going to buy a petrol generator for use on our (fairly small)
boat, it will be for two main purposes:-

Recharging the main batteried when more than a day or two away
from mains electricity.

Running the electric oven/cooker (around 1.2kW).

The battery charging will be via the existing mains chargers so
there's no need for a 12v charger output from the generator. To cope
with the cooker load I think something around 1600 to 1700 watts
should suffice (probably 2kva).

Diesel would be wonderful but I suspect much more expensive and,
possibly, noiser too.

The generator will probably live outside[ish] but boxed in a metal
cabinet to protect it from the weather (and being nicked).

What recommendations do people have? Prices seem to range from around
£200/£250 up to as much as you want to spend. What do you get for
more money and are there any brands to be avoided and/or looked for?


What you get for more money is a quiet(ish) 4-stroke engine, better
reliability and a decent spike-free sine-wave mains output. If any of
these are important to you, have a look at Honda's inverter-based
jobbies. However, a 2kW model (which is what I've got, for providing
emergency essential domestic mains) will set you back about a grand. If
that's too much, have a look at the similar but cheaper ones offered by
Machine Mart. Their 2.2kW Clarke model is under £500.

Thanks, I'll take a look at the Machine Mart ones. I don't know how
critical the microwave will be of non sine-wave electricity, I don't
think anything else will object.

--
Chris Green

wrote:
On Fri, 10 Feb 2012 14:19:28 +0000, wrote:

We're going to buy a petrol generator for use on our (fairly small)
boat, it will be for two main purposes:-



Diesel would be wonderful but I suspect much more expensive and,
possibly, noiser too.

The generator will probably live outside[ish] but boxed in a metal
cabinet to protect it from the weather (and being nicked).

Main thing to ensure that any spilt petrol or vapour from filling or a
leak or can be vented away safely. Petrol vapour is heavier than air
and can accumulate in bilges and other low down areas.

That's why it's going to live outside, on the bathing platform, any
leakage of petrol or vapour will go away fairly harmlessly.


If enough accumulates and then gets ignited it usually ruins somebodys
day. I would stick with diesel for that reason.
Deisel used in a generator can be purchased at a lower duty rate as ll
which is also an advantage, and you can legally store more cans of it
if you have to purchase it and transport it to the boat.
This is a useful guide if you wish to use petrol.
http://www.boatsafetyscheme.com/down...dingPETROL.pdf

The difference isn't so great in France (where the boat is), though
their diesel is cheaper anyway of course.

The trouble with diesel generators is the price and more difficult
starting, I'd prefer manual start if possible.


You don't indicate where you keep and what type of vessel it
is,sometimes the custodians of the water where you wish to use/keep it
have regulations that have to be complied with.

Good point, we have good relations with the capitaine and want to keep
it that way.

--
Chris Green

Dave Liquorice wrote:
On Fri, 10 Feb 2012 14:19:28 +0000, wrote:

Recharging the main batteried when more than a day or two away
from mains electricity.

Don't they recharge from the engine?

Yes, of course, but as that's a 4.5 litre 100bhp diesel it's not the
most economical way to charge the batteries. If we're travelling
along then the batteries will be charged but we want the ability to
stop for, say, 48hrs.


Diesel would be wonderful but I suspect much more expensive and,
possibly, noiser too.

And heavier. I can *just* lift our 2kVA open frame diesel set, mind
you that would normally include 20l of diesel as well. And it is fing
noisy, we can park it with hefty solid stone walls in the way but it
still becomes wearing after a while.

The 2kVA inverter jobbies are good. If I'd had the dosh when getting
a generator I'd bought one and probably the conversion kit to
propane. I'm not keen on petrol, easy to slop and has tendancy to go
WOOF!

Do the "inverter jobbies" generate 12 (or 24) volts and use the
inverter to step it up to 240 volts mains? Can one get generators
without the inverter? We have a 2kva inverter on the boat already.

.... we also have propane for cooking.

Thus a propane drive 12 volt generator would work quite well.


A diesel would mean you could siphon the main engines fuel tank.
Would you have paid full duty on that diesel though, I know the rules
were changing on red diesel and boats but don't know what happened.

It's a bit of a minefield, but mostly you can't use red diesel in
boats now, especially not in France where our boat is.

--
Chris Green

wrote:

What you get for more money is a quiet(ish) 4-stroke engine, better
reliability and a decent spike-free sine-wave mains output. If any of
these are important to you, have a look at Honda's inverter-based
jobbies. However, a 2kW model (which is what I've got, for providing
emergency essential domestic mains) will set you back about a grand. If
that's too much, have a look at the similar but cheaper ones offered by
Machine Mart. Their 2.2kW Clarke model is under £500.

Why should a basic generator, which is actually an alternator, not
produce a true sine wave?

Bill

On Sun, 12 Feb 2012 23:42:00 +0000, wrote:

Yes, of course, but as that's a 4.5 litre 100bhp diesel it's not the
most economical way to charge the batteries. If we're travelling
along then the batteries will be charged but we want the ability to
stop for, say, 48hrs.

Bigger batteries?

Do the "inverter jobbies" generate 12 (or 24) volts and use the
inverter to step it up to 240 volts mains?

Even at 24v 2kVA is 80+ amps before taking into account conversion
losses. Needs significantly chunky bits of copper... I'd say for ease
of handling the alternator chucks out a few hundred volts at a
possibly a higher frequency. The Hondas vary engine speed as well as
throttle setting depending on load. The invertor takes care of
providing stable 50Hz 230v.

I doubt you can buy one without the invertor.

--
Cheers
Dave.

wrote:
Clive George wrote:
On 10/02/2012 14:19, wrote:
We're going to buy a petrol generator for use on our (fairly small)
boat, it will be for two main purposes:-

Recharging the main batteried when more than a day or two away
from mains electricity.
Ok.

Running the electric oven/cooker (around 1.2kW).

It would be very annoying to have to start and run the genny just so you
can cook.

Have you considered the relative cost, convenience, and efficiency of
doing the following:

1. Abandon the idea of using an electric oven. It's mad. Use gas.
2. Install a 200Ah (at 12V) battery set that is dedicated to the
microwave. That will run the micro for about twenty five minutes, in
practice.
3. Use really good intelligent chargers for each battery set. The
chargers to be powered from a 2kW inverter powered in turn from the
engine alternator. This will allow the batteries to be kept in really
good condition and they will be charged quite quickly; far faster than
from the alternator direct.

Running a genny whilst moored is a total pain in the arse. You will be
constantly worried about whether the noise is bothering anyone; you have
to store the fuel; and the bloody thing won't start when you really need
it. And it's very very stealable. Gennys are always getting nicked, and
if you have one visible it attracts thieves who, even if they can't
release the genny will look round for other things. If you only park for
two days it's quite unnecessary to use a genny.

Bill

On Mon, 13 Feb 2012 00:22:36 +0000, Bill Wright wrote:

Why should a basic generator, which is actually an alternator, not
produce a true sine wave?

Winding impedance, reactance of load, saturation of cores.

--
Cheers
Dave.

On Mon, 13 Feb 2012 00:35:23 +0000, Bill Wright wrote:

Running a genny whilst moored is a total pain in the arse. You will be
constantly worried about whether the noise is bothering anyone;

Honda EU20i sets are pretty damn quiet. Nothing like an open frame
set.

... you have to store the fuel; ...

And with petrol or propane on a boat how to make sure the vapours
don't end up in bilge. Petrol would have to stored in with the gas
cyclinder locker that is sealed from the boat and vented to the
outside. Not sure what the regulations say about having an oil fuel
in there as any leak from the container would end up with the fuel in
the watercourse...

... and the bloody thing won't start when you really need it.

Can't say I have any problems starting any of my small engined stuff
from 2 stroke strimmer to single cyclinder diesel genset. Even after
being stood in the unheated garage through the winter.

And it's very very stealable. Gennys are always getting nicked, and
if you have one visible it attracts thieves who, even if they can't
release the genny will look round for other things.

That I will agree with and EU20i's aren't very heavy or particulary
bulky.

If you only park for two days it's quite unnecessary to use a genny.

I think so as well. The OP may need to do some maths on how long the
generator will have to run to recharge the batteries. The main engine
may well be running for 8hrs when cruising, I wouldn't want to run a
generator for that length of time when stopped.

--
Cheers
Dave.

Bill Wright wrote:
wrote:
Clive George wrote:
On 10/02/2012 14:19, wrote:
We're going to buy a petrol generator for use on our (fairly small)
boat, it will be for two main purposes:-

Recharging the main batteried when more than a day or two away
from mains electricity.
Ok.

Running the electric oven/cooker (around 1.2kW).

It would be very annoying to have to start and run the genny just so you
can cook.

Have you considered the relative cost, convenience, and efficiency of
doing the following:

1. Abandon the idea of using an electric oven. It's mad. Use gas.
2. Install a 200Ah (at 12V) battery set that is dedicated to the
microwave. That will run the micro for about twenty five minutes, in
practice.

We have 3 x 200Ah batteries already.

3. Use really good intelligent chargers for each battery set. The
chargers to be powered from a 2kW inverter powered in turn from the
engine alternator. This will allow the batteries to be kept in really
good condition and they will be charged quite quickly; far faster than
from the alternator direct.

We have these too.

Running a genny whilst moored is a total pain in the arse. You will be
constantly worried about whether the noise is bothering anyone; you have
to store the fuel; and the bloody thing won't start when you really need
it. And it's very very stealable. Gennys are always getting nicked, and
if you have one visible it attracts thieves who, even if they can't
release the genny will look round for other things. If you only park for
two days it's quite unnecessary to use a genny.

Well I disagree, 24 hours we can manage but anything longer than that
and we need to recharge the leisure batteries. The main 'base line'
electricity consumption is the refrigerator and we really can't do
much to reduce that.

--
Chris Green

Dave Liquorice wrote:
If you only park for two days it's quite unnecessary to use a genny.

I think so as well. The OP may need to do some maths on how long the
generator will have to run to recharge the batteries. The main engine
may well be running for 8hrs when cruising, I wouldn't want to run a
generator for that length of time when stopped.

Our 'cruising' isn't like that! For relaxed travelling one does only
three or four hours travelling each day and some days one does none at
all.

We have had the boat for almost two years now and it's after two years
experience that we have decided that we need a generator, even with
600Ah of batteries.

--
Chris Green

Dave Liquorice wrote:
On Sun, 12 Feb 2012 23:42:00 +0000, wrote:

Yes, of course, but as that's a 4.5 litre 100bhp diesel it's not the
most economical way to charge the batteries. If we're travelling
along then the batteries will be charged but we want the ability to
stop for, say, 48hrs.

Bigger batteries?

We already have 3 x 200AH.


Do the "inverter jobbies" generate 12 (or 24) volts and use the
inverter to step it up to 240 volts mains?

Even at 24v 2kVA is 80+ amps before taking into account conversion
losses. Needs significantly chunky bits of copper... I'd say for ease
of handling the alternator chucks out a few hundred volts at a
possibly a higher frequency. The Hondas vary engine speed as well as
throttle setting depending on load. The invertor takes care of
providing stable 50Hz 230v.

Ah, I see, the inverter is between "varying voltage and frequency" and
"240 volt sine wave". That makes a lot of sense.

--
Chris Green

wrote:
Bill Wright wrote:
wrote:
Clive George wrote:
On 10/02/2012 14:19, wrote:
We're going to buy a petrol generator for use on our (fairly small)
boat, it will be for two main purposes:-

Recharging the main batteried when more than a day or two away
from mains electricity.
Ok.

Running the electric oven/cooker (around 1.2kW).
It would be very annoying to have to start and run the genny just so you
can cook.

Have you considered the relative cost, convenience, and efficiency of
doing the following:

1. Abandon the idea of using an electric oven. It's mad. Use gas.
2. Install a 200Ah (at 12V) battery set that is dedicated to the
microwave. That will run the micro for about twenty five minutes, in
practice.

We have 3 x 200Ah batteries already.

3. Use really good intelligent chargers for each battery set. The
chargers to be powered from a 2kW inverter powered in turn from the
engine alternator. This will allow the batteries to be kept in really
good condition and they will be charged quite quickly; far faster than
from the alternator direct.

We have these too.

Running a genny whilst moored is a total pain in the arse. You will be
constantly worried about whether the noise is bothering anyone; you have
to store the fuel; and the bloody thing won't start when you really need
it. And it's very very stealable. Gennys are always getting nicked, and
if you have one visible it attracts thieves who, even if they can't
release the genny will look round for other things. If you only park for
two days it's quite unnecessary to use a genny.

Well I disagree, 24 hours we can manage but anything longer than that
and we need to recharge the leisure batteries. The main 'base line'
electricity consumption is the refrigerator and we really can't do
much to reduce that.

Gas fridge?

--
Tciao for Now!

John.

John Williamson wrote:
Running a genny whilst moored is a total pain in the arse. You will be
constantly worried about whether the noise is bothering anyone; you have
to store the fuel; and the bloody thing won't start when you really need
it. And it's very very stealable. Gennys are always getting nicked, and
if you have one visible it attracts thieves who, even if they can't
release the genny will look round for other things. If you only park for
two days it's quite unnecessary to use a genny.

Well I disagree, 24 hours we can manage but anything longer than that
and we need to recharge the leisure batteries. The main 'base line'
electricity consumption is the refrigerator and we really can't do
much to reduce that.

Gas fridge?

While there are such things they are rare now, and expensive (as is
anything specifically for boats etc.).

--
Chris Green

Dave Liquorice wrote:
On Mon, 13 Feb 2012 00:35:23 +0000, Bill Wright wrote:

Running a genny whilst moored is a total pain in the arse. You will be
constantly worried about whether the noise is bothering anyone;

Honda EU20i sets are pretty damn quiet. Nothing like an open frame
set.
I have one, and in a very quiet location I am always worried that it
will disturb people.



... and the bloody thing won't start when you really need it.

Can't say I have any problems starting any of my small engined stuff
from 2 stroke strimmer to single cyclinder diesel genset. Even after
being stood in the unheated garage through the winter.
No, but Sod's Law does apply.


If you only park for two days it's quite unnecessary to use a genny.

I think so as well. The OP may need to do some maths on how long the
generator will have to run to recharge the batteries. The main engine
may well be running for 8hrs when cruising, I wouldn't want to run a
generator for that length of time when stopped.

Even using 15A intelligent chargers, one for each battery set, I need
eight hours for a full charge.

Bill

John Williamson wrote:

We have 3 x 200Ah batteries already.

If you only park for two days it's quite unnecessary to use a
genny.

Well I disagree, 24 hours we can manage but anything longer than that
and we need to recharge the leisure batteries. The main 'base line'
electricity consumption is the refrigerator and we really can't do
much to reduce that.

I can't imagine why you need all that power. Is this a big mains fridge
running from an inverter? I have a 24VDC fridge that draws 2A. The duty
cycle is about 25% on 75% off in normal ambient temps. The fridge has a
thermal 'sink' which means that it keeps cold for 8 hours with no power,
as long as that follows a longish period of being powered.

I though I was an intensive power glutton but we can go two winter days
and nights with electrically driven gas powered central heating,
electric fridge, telly, PVR, lights, etc. That's on a total of five
110Ah 12V batteries.

I have a genny but it's very rare I use it.

Would a small wind turbine suit you better, by the way, just to top up?

Bill

On Mon, 13 Feb 2012 14:47:51 +0000, Bill Wright wrote:

Honda EU20i sets are pretty damn quiet. Nothing like an open frame
set.

I have one, and in a very quiet location I am always worried that it
will disturb people.

You haven't heard my open frame diesel set. It's hard to hold a
conversation next to it when running...

Even using 15A intelligent chargers, one for each battery set, I need
eight hours for a full charge.

That's what I thought and possibly not what the OP has, hence doing
the maths. I'm surprised that 600AH doesn't last two days, that's an
average drain of 12.5A or 150W over 48hrs.

I think perhaps a survey of what is really taking the energy is in
order. The "small" load" of 50W for lights over 8 hours takes the
same energy as the "large load "1200W microwave uses in 15 mins.

--
Cheers
Dave.

Bill Wright wrote:
John Williamson wrote:

We have 3 x 200Ah batteries already.

If you only park for two days it's quite unnecessary to use a
genny.

Well I disagree, 24 hours we can manage but anything longer than that
and we need to recharge the leisure batteries. The main 'base line'
electricity consumption is the refrigerator and we really can't do
much to reduce that.

I can't imagine why you need all that power. Is this a big mains fridge
running from an inverter? I have a 24VDC fridge that draws 2A.

Yes.

The duty
cycle is about 25% on 75% off in normal ambient temps. The fridge has a
thermal 'sink' which means that it keeps cold for 8 hours with no power,
as long as that follows a longish period of being powered.

I bet it cost an arm and a leg (relative to a normal mains powered
domestic one) *and* isn't very big.


I though I was an intensive power glutton but we can go two winter days
and nights with electrically driven gas powered central heating,
electric fridge, telly, PVR, lights, etc. That's on a total of five
110Ah 12V batteries.

I don't think any of that electronic stuff uses much, we have quite a
lot of "always on" stuff like that, a router, an eeePc, etc. Those
don't cause any problems really.


I have a genny but it's very rare I use it.

Would a small wind turbine suit you better, by the way, just to top up?

If you look into the economics/effectiveness of a turbine it really
doesn't help much.

For keeping the batteries healthy over winter and other times when the
boat is laid up a turbine or solar cells can provide what's needed but
for actual living on board one needs a little more. Other members of
the DBA (the barge association) who run bigger boats than I have and
expect to be able to be independent of shore power nearly *all* have a
generator which they run regularly. Some have *large* areas of solar
cells which provide most of their top-up power but they usually have a
generator as well.

--
Chris Green

Dave Liquorice wrote:
On Mon, 13 Feb 2012 14:47:51 +0000, Bill Wright wrote:

Honda EU20i sets are pretty damn quiet. Nothing like an open frame
set.
I have one, and in a very quiet location I am always worried that it
will disturb people.

You haven't heard my open frame diesel set. It's hard to hold a
conversation next to it when running...
Well, I used have one of those for site work in the days before battery
tools. What a noisy bugger!


Even using 15A intelligent chargers, one for each battery set, I need
eight hours for a full charge.

That's what I thought and possibly not what the OP has, hence doing
the maths. I'm surprised that 600AH doesn't last two days, that's an
average drain of 12.5A or 150W over 48hrs.

I think perhaps a survey of what is really taking the energy is in
order. The "small" load" of 50W for lights over 8 hours takes the
same energy as the "large load "1200W microwave uses in 15 mins.
Lighting uses a lot as you say because it's on a long time. The more
lights there are the less power used because the light is targeted. A
10W halogen spot makes a really effective task light/ reading light.
LEDs even better but I won't use them because they aren't continuous
spectrum. High efficiency lighting can make a massive difference though.
Ye olde fashioned 12V fluorescents (good quality ones) can be a good
solution.

It can be quite pleasant to supplement the lighting with a Tilley. Quite
a nice atmosphere.

Incidentally my microwave draws 45A at 24VDC. Not too bad if you say it
quick. We normally try to remember to use the micro when the engine is
still running.

Bill

Dave Liquorice wrote:
On Mon, 13 Feb 2012 14:47:51 +0000, Bill Wright wrote:

Honda EU20i sets are pretty damn quiet. Nothing like an open frame
set.

I have one, and in a very quiet location I am always worried that it
will disturb people.

You haven't heard my open frame diesel set. It's hard to hold a
conversation next to it when running...

Even using 15A intelligent chargers, one for each battery set, I need
eight hours for a full charge.

That's what I thought and possibly not what the OP has, hence doing
the maths. I'm surprised that 600AH doesn't last two days, that's an
average drain of 12.5A or 150W over 48hrs.

12.5 x 48 = 600, yes I agree, however that's to "totally discharged",
if you ever get there your battery is dead. Even with "deep
discharge" leisure batteries it's not recommended to take them below
50% charge.

When the refrigerator is running the inverter draws about 8 amps, in
hot weather thats for quite a lot of the time. Given that one doesn't
want to get below 50% charge we're down to less than 48 hours with
nothing else on at all.

--
Chris Green

wrote:
John Williamson wrote:
Running a genny whilst moored is a total pain in the arse. You will be
constantly worried about whether the noise is bothering anyone; you have
to store the fuel; and the bloody thing won't start when you really need
it. And it's very very stealable. Gennys are always getting nicked, and
if you have one visible it attracts thieves who, even if they can't
release the genny will look round for other things. If you only park for
two days it's quite unnecessary to use a genny.

Well I disagree, 24 hours we can manage but anything longer than that
and we need to recharge the leisure batteries. The main 'base line'
electricity consumption is the refrigerator and we really can't do
much to reduce that.

Gas fridge?

While there are such things they are rare now, and expensive (as is
anything specifically for boats etc.).

I had a three way one (Mains, 12 volt and gas) in various caravans. The
same one in the chandlers cost about twice the price, as did the
identical wall spotlights.

--
Tciao for Now!

John.

On 13/02/2012 11:14, wrote:
Dave wrote:
On Sun, 12 Feb 2012 23:42:00 +0000, wrote:

Yes, of course, but as that's a 4.5 litre 100bhp diesel it's not the
most economical way to charge the batteries. If we're travelling
along then the batteries will be charged but we want the ability to
stop for, say, 48hrs.

Bigger batteries?

We already have 3 x 200AH.


Do the "inverter jobbies" generate 12 (or 24) volts and use the
inverter to step it up to 240 volts mains?

Even at 24v 2kVA is 80+ amps before taking into account conversion
losses. Needs significantly chunky bits of copper... I'd say for ease
of handling the alternator chucks out a few hundred volts at a
possibly a higher frequency. The Hondas vary engine speed as well as
throttle setting depending on load. The invertor takes care of
providing stable 50Hz 230v.

Ah, I see, the inverter is between "varying voltage and frequency" and
"240 volt sine wave". That makes a lot of sense.


I've investigated inside a sinewave generator before.
The alternator was a 3-phase unit, output several hundred volts IIRC.
The engine throttle is controlled by a stepper motor, and automatically
adjusted by the system to match the load - keeping the speed (and noise
/ fuel consumption) as low as possible.
The inverter took care of the variable input and produced a *very* good
sinewave output (viewed on a 'scope, under load)

All very clever. Makes traditional governor controlled open-frame
generators look very crude. (Which they are!)

wrote:

I can't imagine why you need all that power. Is this a big mains fridge
running from an inverter? I have a 24VDC fridge that draws 2A.

Yes.

The duty
cycle is about 25% on 75% off in normal ambient temps. The fridge has a
thermal 'sink' which means that it keeps cold for 8 hours with no power,
as long as that follows a longish period of being powered.

I bet it cost an arm and a leg (relative to a normal mains powered
domestic one) *and* isn't very big.
It cost £250. The brand is 'Waeco' I think. It isn't very big but it's
big enough. It's about 2/3rds of the size of a normal domestic fridge I
guess. If you examine what you put in the fridge a lot of it needn't be
there.
Incidentally I found it greatly reduces the power consumption of a
fridge to mount it on an outside wall and fit two vents to the outside,
one at the top and one at the bottom of the radiator thing on the
fridge-back that gets hot, and seal around the fridge so the vents can't
let a draught in. There's quite a good chimney effect.

Bill

Bill Wright wrote:
wrote:

I can't imagine why you need all that power. Is this a big mains fridge
running from an inverter? I have a 24VDC fridge that draws 2A.

Yes.

The duty
cycle is about 25% on 75% off in normal ambient temps. The fridge has a
thermal 'sink' which means that it keeps cold for 8 hours with no power,
as long as that follows a longish period of being powered.

I bet it cost an arm and a leg (relative to a normal mains powered
domestic one) *and* isn't very big.
It cost £250. The brand is 'Waeco' I think. It isn't very big but it's
big enough. It's about 2/3rds of the size of a normal domestic fridge I
guess. If you examine what you put in the fridge a lot of it needn't be
there.

So it cost more than twice as much as an ordinary domestic fridge
which is also bigger. I can pay for part of my generator (or maybe,
alternatively buy some solar cells) for that difference and have a
bigger fridge too.

Most larger boats find that standardising on using mains power for
almost everything and using an inverter and/or generator saves money
in the long run because of the exorbitant cost of anything that runs
on 12 or 24 volts and designed for boats etc.

Our problem is that we're just "on the cusp" as it were between being
a big boat where it makes sense to run everything on 240 volts (like
in bigger boats) or to do everything on a camping/caravanning sort of
basis and find 12 volt ways of doing things.


Incidentally I found it greatly reduces the power consumption of a
fridge to mount it on an outside wall and fit two vents to the outside,
one at the top and one at the bottom of the radiator thing on the
fridge-back that gets hot, and seal around the fridge so the vents can't
let a draught in. There's quite a good chimney effect.

Good idea, unless/until the outside temperature gets too low and the
refrigerant can't do its job by evaporating at the right place.
Fridges have a minimum ambient temperature below which they can stop
working properly.

--
Chris Green

wrote:

I bet it cost an arm and a leg (relative to a normal mains powered
domestic one) *and* isn't very big.
It cost £250. The brand is 'Waeco' I think. It isn't very big but it's
big enough. It's about 2/3rds of the size of a normal domestic fridge I
guess. If you examine what you put in the fridge a lot of it needn't be
there.

So it cost more than twice as much as an ordinary domestic fridge
which is also bigger. I can pay for part of my generator
Yes but you have to put fuel in a genny and it makes a racket and you
have to actually start it and stop it.

Most larger boats find that standardising on using mains power for
almost everything and using an inverter and/or generator saves money
in the long run because of the exorbitant cost of anything that runs
on 12 or 24 volts and designed for boats etc.
That's a very good point. I always advise my customers to use mains TV
eqpt and a small inverter.


Our problem is that we're just "on the cusp" as it were between being
a big boat where it makes sense to run everything on 240 volts (like
in bigger boats) or to do everything on a camping/caravanning sort of
basis and find 12 volt ways of doing things.
My attitude to that is to have both. In my motorhome I have a 12V supply
that has a small battery and a permanent charge from the mains or one of
the 24V supplies. The 12V supply is for the radio, the alarm, some of
the lights, etc. But I run the inverter all the time when driving and
almost all the time when parked up. The inverter powers the cameras and
monitor for instance.


Incidentally I found it greatly reduces the power consumption of a
fridge to mount it on an outside wall and fit two vents to the outside,
one at the top and one at the bottom of the radiator thing on the
fridge-back that gets hot, and seal around the fridge so the vents can't
let a draught in. There's quite a good chimney effect.

Good idea, unless/until the outside temperature gets too low and the
refrigerant can't do its job by evaporating at the right place.
Fridges have a minimum ambient temperature below which they can stop
working properly.
I forgot to say, you can buy a kit comprising two vents with baffles for
use when it's really cold, from Electrolux. But I used two ordinary
large domestic vents with sliding baffles.

Bill

In message , writes
John Williamson wrote:
Running a genny whilst moored is a total pain in the arse. You will be
constantly worried about whether the noise is bothering anyone; you have
to store the fuel; and the bloody thing won't start when you really need
it. And it's very very stealable. Gennys are always getting nicked, and
if you have one visible it attracts thieves who, even if they can't
release the genny will look round for other things. If you only park for
two days it's quite unnecessary to use a genny.

Well I disagree, 24 hours we can manage but anything longer than that
and we need to recharge the leisure batteries. The main 'base line'
electricity consumption is the refrigerator and we really can't do
much to reduce that.

Gas fridge?

While there are such things they are rare now, and expensive (as is
anything specifically for boats etc.).

Are they any different to those used in touring caravans? Those are
readily available and if you don't want to buy new go to a breaker.
They're all 3 way, mains, gas, 12v. Not just fridges but fridge freezers
also.

A fridge on 12v soon flattens a battery, only used when connected to car
and engine running on caravans.
Latest models have automatic energy source selection - mains - gas - 12v
--
hugh

hugh wrote:

A fridge on 12v soon flattens a battery, only used when connected to car
and engine running on caravans.
Latest models have automatic energy source selection - mains - gas - 12v

These are absorption types. They draw 17A at 12V. The ones with a motor
are far better and use a tenth as much power. Absorption ones aren't
practical for ships etc because they have to be perfectly level when
used on gas.

Bill

In message , Bill Wright
writes
hugh wrote:

A fridge on 12v soon flattens a battery, only used when connected to
car and engine running on caravans.
Latest models have automatic energy source selection - mains - gas - 12v

These are absorption types. They draw 17A at 12V. The ones with a motor
are far better and use a tenth as much power. Absorption ones aren't
practical for ships etc because they have to be perfectly level when
used on gas.

Bill
Not "perfectly" level, but yes they do have a maximum tolerance - mine
won't work if the caravan is parked on my sloping drive. This applies
regardless of energy source.
I can see that being a problem with a ship, but a canal boat?
--
hugh