Generators

[nearlythere]

Hi all

 

Another question that I hope some of you can help with please. We are looking into acquiring a generator and wondered what is the best size ie as in power output? As we may not always have a shoreline, this would be used to help provide additional power and to give the boat's batteries a boost save us running the engine up? What sort of output should we be looking at and what are your thoughts on diesel vs petrol.Any particular brands to avoid or go for?

 

Many thanks in advance.

[BEngo]

Hi all

 

Another question that I hope some of you can help with please. We are looking into acquiring a generator and wondered what is the best size ie as in power output? As we may not always have a shoreline, this would be used to help provide additional power and to give the boat's batteries a boost save us running the engine up? What sort of output should we be looking at and what are your thoughts on diesel vs petrol.Any particular brands to avoid or go for?

 

Many thanks in advance.

 

What do you want to provide additional power for? How many things do you want to use at once? The maximum power demand of all the things you want to use at once will set the smallest size of generator you need- and you will need to allow fore some start-up surge.

 

 

Petrol gennies are cheaper and lighter than diesel, but more expensive to run. Diesels are generally noisy unless built-in and well cocooned. Diesel as a fuel is much lower fire risk than petrol and you probably already have a tank. You also have an LPG tank, probaly and some petrol genberators can be converted to run on LPG.

 

Honda generators have a good reputation and the EU10i and 20i seem to be well liked- but they are not the cheapest.

 

N

[Arthur Brown]

http://www.victronenergy.com/upload/documents/Book-EN-EnergyUnlimited.pdf

 

Read the book and understand it. Note the solutions they offer and try to apply them to your situation, which you haven't said much about!

 

Consider whether you need a DC generator to charge your batteries and support 12vdc appliances, or a 230VAC generator to run AC things and drive a battery charger.

 

Consider whether you are looking for a hand portable unit or one built into the engine room.

 

Start with knowing exactly what power you draw from your hook-up (peak and average)

 

Look also at the exhaust system. You will be unpopular running a standard generator for long as they are noisy. Most of the noise is in the exhaust so fabricating a wet exhaust for a built in genset can be MUCH more sociable than leaving a hot exhaust banging away into the night.

 

Remember that cheap gensets have very poor regulation and may well put out over 300v unless loaded into the middle of their rating (mine does! 325vac unloaded ) However a small petrol generator will be found for sub £100 and a nice big diesel will cost as much as the boat.

 

Added;

This one is so cheap but it is small and noisy and petrol or may even be two stroke,

http://www.ebay.co.uk/itm/MARKSMAN-GENERATOR-950-DC-12V-8-3-SINGLE-PHASE-4-LTR-UNTESTED-/130627841093?pt=UK_BOI_Industrial_Tools_Generators_ET&hash=item1e6a06ac45

 

This one is expensive but charges batteries directly at a fair rate.

http://www.ebay.co.uk/itm/PORTABLE-GENERATOR-50-AMP-12-VOLT-QUIET-BATTERY-CHARGER-MOTORHOME-CARAVAN-BOAT-/200700691064?pt=UK_BOI_Industrial_Tools_Generators_ET&hash=item2ebab18278

Edited January 15, 2012 by Arthur Brown

[nearlythere]

What do you want to provide additional power for? How many things do you want to use at once? The maximum power demand of all the things you want to use at once will set the smallest size of generator you need- and you will need to allow fore some start-up surge.

 

 

Petrol gennies are cheaper and lighter than diesel, but more expensive to run. Diesels are generally noisy unless built-in and well cocooned. Diesel as a fuel is much lower fire risk than petrol and you probably already have a tank. You also have an LPG tank, probaly and some petrol genberators can be converted to run on LPG.

 

Honda generators have a good reputation and the EU10i and 20i seem to be well liked- but they are not the cheapest.

 

N

 

Thank you for your quick reply. We would be looking maybe to run say the washing m/c, or the laptop as an extra? Would it be something around the 3kw mark? Thanks again

 

http://www.victronenergy.com/upload/documents/Book-EN-EnergyUnlimited.pdf

 

 

Thank you, this is extremely useful and will be passed on to HWMBO for bedtime reading

[jelunga]

Thank you for your quick reply. We would be looking maybe to run say the washing m/c, or the laptop as an extra? Would it be something around the 3kw mark? Thanks again

 

 

 

Thank you, this is extremely useful and will be passed on to HWMBO for bedtime reading

 

 

I have a petrol Kipor 2600. It was cheap, but it is relatively quiet, and runs on invertor technology so is "economic", well as much as a generator can be.

Some people say they are rubbish and fail quickly. Others like them. My view is that as they are 1/3rd of the price of an equivalent Honda, you get 3 Kipors / Honda.

 

Mine has run only low hours at the moment, some 30 hrs odd. The only trouble I have is starting it after it has sat for a while when it takes a few minutes for the carburettor to fill with fuel.

[BEngo]

Thank you for your quick reply. We would be looking maybe to run say the washing m/c, or the laptop as an extra? Would it be something around the 3kw mark? Thanks again

 

 

 

Thank you, this is extremely useful and will be passed on to HWMBO for bedtime reading

 

 

The power demand for a washing machine will vary a lot. When it is heating water then up to about 3kW, depending on the machine and the heater, but when just washing, less than 1kW. You will need to check either the rating plate odr the makers handbook. The laptop is probaly less than 500W, but using 240v for laptop is less effective than buying a 'proper' 12V powerpack. (unless you have a Dell which are renowned for being deliberately awkward).

 

A 3kW genny will be fine for the w/m (on its own whilst the heater is going) but you may find the electronics don't much like the generator- small generators are notoriously 'noisy' in electrical terms and some of the inverter generators have a very poor waveform. If possible try before you buy.

 

Diesel engines do not like running at light load so a, say, 3kW genny thrashing round at 3000rpm and 500W will not be happy over a long period unless it gets a good run at 2500W or so to clear it out.

 

Generators with auxiliary outputs which charge batteries at 12v are, as a rule, less use than the 240v generator output charging through a decent battery charger. This is not true for a purpose-designed battery charging generator, but the yopu don't get the advantages of having 240v.

 

Skin cooled generators need larger skin tanks than you would think, at least twice as big as a propulsion engine of the same size, because there is no water flow over them whilst you are stationary.

 

I have no experience of the alternator and inverter devices like the travelpower, but if your engine is suitable these might be an option.

 

Read the victron handout, remembering they do have equipment to sell, then write down what it is you want to run, when, for how long and how much power it will consume. Armed with that information you should get some more specific solutions which you can compare with your budget.

 

N

Edit for spillking

Edited January 15, 2012 by BEngo

[The Bagdad Boatman (waits)]

You can't beat the honda li for being super quite bug greedy on petrol. I see that ebay are advertising super silent klipor diesel gennys for a reasonable price.

[TUGBOAT]

Hi all

 

Another question that I hope some of you can help with please. We are looking into acquiring a generator and wondered what is the best size ie as in power output? As we may not always have a shoreline, this would be used to help provide additional power and to give the boat's batteries a boost save us running the engine up? What sort of output should we be looking at and what are your thoughts on diesel vs petrol.Any particular brands to avoid or go for?

 

Many thanks in advance.

 

A little tip here if you intend to use a washing machine fill it with your clothes and soap powder then poor hot water in before you close the door and this will save you a lot of power from your genni as most power is used to heat the water.

 

Reagards

 

John

[bottle]

I have never been able to see the logic of this, the generator is running so where is the saving.

 

If you get the water temperature wrong (to low) the heating element will still kick in and the generator will still have to supply the power.

 

Of course if you get the temperature to high the only thing that may suffer is the clothes.

 

There is another factor hot water has to be available.

 

Disconnecting the heating element will still not help, see above about temperature (low)

[mrsmelly]

I have never been able to see the logic of this, the generator is running so where is the saving.

 

If you get the water temperature wrong (to low) the heating element will still kick in and the generator will still have to supply the power.

 

Of course if you get the temperature to high the only thing that may suffer is the clothes.

 

There is another factor hot water has to be available.

 

Disconnecting the heating element will still not help, see above about temperature (low)

 

This is all of course very true. Perhaps the best way forward is a good machine with quality washing up stuff ( Womens work ) and a cold wash button which eliminates the heaters, if we do that with ours we can run it straight off the inverter with engine off and it uses very little power at any stage of the cycle, I know cos I am a sad git and watched mi ampgauge thingy

[Justme]

I have never been able to see the logic of this, the generator is running so where is the saving.

 

 

 

The generator does not consume the same amount of fuel for all loads. So if the water is hot (hotter than the cold) then some fuel will be saved even if the heater still needs to come on to get the water up to full temp.

 

Down side is that gennies have a minimum amount that it takes to run them so running on low loads for long periods can be costly.

 

Our solution is to either do the washing when the genny needs to be on anyway to charge the bats or use the power level settings of the Victron software to start the genny when the heater cuts in but to stop it when it cuts out. The inverter can easily handle the actual wash cycles minus the heater run times.

[cereal tiller]

This is all of course very true. Perhaps the best way forward is a good machine with quality washing up stuff ( Womens work ) and a cold wash button which eliminates the heaters, if we do that with ours we can run it straight off the inverter with engine off and it uses very little power at any stage of the cycle, I know cos I am a sad git and watched mi ampgauge thingy

My boat has a CANDY ECLYPSA washing machine,which is ten years old.

 

it has a HOT and a COLD inlet,the heating element was disconnected on the day it was installed in the boat,and has never been used.

 

the washing machine is just 2 feet of pipe run from the calorifier,and it mixes hot and cold water to obtain the correct temperature.

 

a LONG and hot wash can be carried out without the main engine or genarator running,the inverter and battery bank cope with the power demand.

 

i understand that only cold fill machines are available these days,when the candy is worn out the only replacement has to be a TWINTUB?

 

I also have a HONDA g28 engine with a centrifugal clutch which drives a 70 AMP alternator,more efficient than an A.C. genset ,and the amperage can be varied by adjusting the engine speed.

Edited January 20, 2012 by cereal tiller

[bottle]

it mixes hot and cold water to obtain the correct temperature

 

How?

[Eeyore]

This one is expensive but charges batteries directly at a fair rate.

http://www.ebay.co.uk/itm/PORTABLE-GENERATOR-50-AMP-12-VOLT-QUIET-BATTERY-CHARGER-MOTORHOME-CARAVAN-BOAT-/200700691064?pt=UK_BOI_Industrial_Tools_Generators_ET&hash=item2ebab18278

Interesting find Arthur, but the claims they make on thier website are very questionable.

Its a blatant copy of an "Outback" battery charger by Christie Engineering in Australia.

The "Outback" has a genuine Honda engine and Bosch alternator, this one has an unknown (probably Chinese clone) engine and what appears to be a Lucas ACR type alternator.

Their claim to be able to recharge a 70amp(hour) battery from 50% depth of discharge in 42 mins makes Star Trek seem more believable.

If I didn't already own the genuine article I might be tempted to have a look at one, but to my mind its seriously over priced.

Steve

[Arthur Brown]

Yes the ebay item comes with all the provenance that ebay confers -none! I expect it will work for a while at less performance and more noise than specified -HOWEVER it is a useful concept a string start genset capable of charging batteries rapidly

 

If cold fill washers are all that exist, what is to stop people from fitting a mixer tap to the feed? If the water goes in the cold tap at 60C then it will not take much heating if any, then turn the thermostat to cold for the rinses.

[mrsmelly]

 

 

i understand that only cold fill machines are available these days,

 

Hi

 

This is a popular myth. It is true they are not as readily available as they once were but Hot and Cold fill machines are readily available. My Lg direct drive 7kg machine is both hot and cold fill, can wash one sock or anything up to a full load and has no drive belt to snap. They are not cheap at around 700 quid but I suppose as with most things you get what you pay for.

[Guest wanted]

I have just been told that these guys sometimes have some recon hondas for a lot cheaper than the going rate. Might be worth a sniff?

http://www.brownpower.co.uk/generators_leisure.html

[Arthur Brown]

The point of my link was that you could poll a string and start the charger to recharge a boat's batteries simply and quickly, without having to have a genset and battery charger.

 

As ever someone will have something cheap to offer as recon or second user.

 

Having seen on ebay the inverter unit for a Honda genset I began to wonder, could a generator spun by the marine engine be used to feed the inverter board giving 240v 50Hz from whatever revs the propellor needs???

[smileypete]

How?

Generally they still cold fill for wash temperatures of 60°C or below.

 

Above that they hot fill and top up with the heater as and when needed.

 

cheers,

Pete.

[Timleech]

The point of my link was that you could poll a string and start the charger to recharge a boat's batteries simply and quickly, without having to have a genset and battery charger.

 

As ever someone will have something cheap to offer as recon or second user.

 

Having seen on ebay the inverter unit for a Honda genset I began to wonder, could a generator spun by the marine engine be used to feed the inverter board giving 240v 50Hz from whatever revs the propellor needs???

 

I built my own charging set years ago with a Petter AA1 (v.small diesel) and 11AC alternator, with belt drive. Noisy, but cheap to make and to run & worked very well.

 

Your last point sounds like reinventing the Travel Power unit.

 

Tim

[bottle]

Hi Pete

 

Maybe my quote was little 'short'. quoting a little more and highlighting may make the point more obvious.

 

it has a HOT and a COLD inlet,the heating element was disconnected on the day it was installed in the boat,and has never been used.

 

the washing machine is just 2 feet of pipe run from the calorifier,and it mixes hot and cold water to obtain the correct temperature.

 

There are so many variables as to the final water temperature that just filling with both will not give the correct temperature.

 

ps. I may be have been being a little tongue in cheek.

[Arthur Brown]

Yes I was looking at a solution for the flat batery miles down the cut, and a pull start unit seemed good, eswpecially if it had an automotive alternator with regulator suited to lead acid included rather than added on later.

[cereal tiller]

How?

yes,HOW..,greetings to you oh great chief of the plains....

 

Always assumed it must have internal temp. control.

 

if a 40 degree temp is selected the water in the drum is neither hot nor cold.

 

the calorifier water can be as high as 73 degrees,so it must be reduced inside the machine?

[Justme]

Use an easily adjustable TMV (not all are easy to adjust)or a shower tap fitting with built in TMV.

 

(TMV= Thermostatic Mixer Valve)

 

Set it to the wash temp for the fill & then turn down for the rinses.

[bottle]

Exactly. but even then the exact temperature in the machine will be unknown

 

the calorifier water can be as high as 73 degrees,so it must be reduced inside the machine?

 

True but it will always be mixed with the cold and the flow is usually higher on the cold, so the maximum temperature in the machine will be lower than the minimum wash temperature.

 

Any wash cycle at a higher temperature will require the heating element to work.

Edited January 21, 2012 by bottle