Generators?

[Khayamanzi]

Just wondering, I have seen some people with very neat and fairly silent little generators that they plug into their landline socket and use to charge their batteries. I have just started thinking the same. The advantage seems to be that the gennerator can be positioned on the bank away from the boat in secluded areas without the need to run the engine which vibrates through the boat. I have a 2.5KW Mastervolt combi unit with an adverc battery management system. Is there anything I would need to be aware of and which makes/models do people find the best for this purpose - if I plug it in, will my 240v power come from that and over-ride my inverter? I know nothing about this configuration and so am intrigued by peoples responses?

Any help?

many thanks

Andy

[Gary Peacock]

Just wondering, I have seen some people with very neat and fairly silent little generators that they plug into their landline socket and use to charge their batteries. I have just started thinking the same. The advantage seems to be that the gennerator can be positioned on the bank away from the boat in secluded areas without the need to run the engine which vibrates through the boat. I have a 2.5KW Mastervolt combi unit with an adverc battery management system. Is there anything I would need to be aware of and which makes/models do people find the best for this purpose - if I plug it in, will my 240v power come from that and over-ride my inverter? I know nothing about this configuration and so am intrigued by peoples responses?

Any help?

many thanks

Andy

 

Both Mastervolt and Victron equipment can be a bit fussy about accepting the output from small generators if the frequency is a bit iffy. The only real test is to try it.

[DHutch]

Cant say about Mastervolt or Victron, but we have a Honda EX1000 genny which works fine on our Sterling Charger.

- Even if where messing up the frequency somthing cronic with a big 750w drill fluing the tubes.

 

 

Daniel

[Ernie]

I am also looking at a similar sort of set up but am thinking about going for diesel rather than a petrol generator for safety and also ease of obtaining fuel. If on the boat for a long period on the move, I don't want to have to travel to get petrol and I am not keen on the idea of storing petrol on the boat while staying on it.

 

Also, I thought that if I am going to buy a generator to keep the batteries charged while moored up for a while, I may as well go for one powerful enough to run the washing machine and hoover etc. Maybe this is not such a great idea - I have a 3.5kW Electrolux generator on the engine but don't like having to run the engine for long periods of time without a load on it. To get a reasonable output from the Electrolux, I need to run the engine at around 1500 RPM so then have problems with noise and vibration.

Regards

Ernie

[bottle]

I am also looking at a similar sort of set up but am thinking about going for diesel rather than a petrol generator for safety and also ease of obtaining fuel. If on the boat for a long period on the move, I don't want to have to travel to get petrol and I am not keen on the idea of storing petrol on the boat while staying on it.

 

Also, I thought that if I am going to buy a generator to keep the batteries charged while moored up for a while, I may as well go for one powerful enough to run the washing machine and hoover etc. Maybe this is not such a great idea - I have a 3.5kW Electrolux generator on the engine but don't like having to run the engine for long periods of time without a load on it. To get a reasonable output from the Electrolux, I need to run the engine at around 1500 RPM so then have problems with noise and vibration.

Regards

Ernie

 

It has been said that running the engine with a 3.5Kw generator is enough load for the engine.

[Ernie]

Thanks bottle,

 

I am also concerned about the noise and vibration from running the engine. I am hoping that a generator up at the bow (my cabin is at the stern) will be a lot quieter and vibration should be minimal - maybe I am hoping for too much?

 

Regards

Ernie

[bottle]

(my cabin is at the stern)

 

Ah! that would make a difference, I do not know the type of engine you have, if its a thumper then I suspect the vibration would be excessive but as you have 3.5Kw gen. I would imagine it is a modern one.

 

The engine should not vibrate excessivley if it is have the mountings checked, also if the noise is to much have you thought of sound insulation.

 

Just some thoughts, of course check all the costings but personally I would be loathe to buy another generator when I already had one.

[Ernie]

Bottle,

 

You could well be right, perhaps a generator isn't the answer. Perhaps I should go for a big charger and run it off the 3.5kW Electrolux. I have a 90A alternator but even at reasonable revs, it doesn't seem to put a lot of charge into the batteries. It means running the engine ( a Nannidiesel 1.9) and living with the noise and vibration but with a big charger, perhaps I shouldn’t have to run it for too long??

 

I think I have pulled this thread off topic from Andy's original question - sorry.

 

At the end of the day, I guess what I really need is an efficient way of charging my batteries without running the engine for extended periods. The batteries are 4 years old now, perhaps replacing them in conjunction with better charging is the answer??

 

Cheers

Ernie

[bottle]

The batteries are 4 years old now, perhaps replacing them in conjunction with better charging is the answer??

 

Hi Ernie

 

If the batteries are taking excessive time to charge maybe one or more of them has a 'duff'' (technical word ) cell. Try checking with an hydrometer.

 

This is now going outside my understanding but is the 90amp alternator battery sensed, my understanding is this gives a better chargeing rate and also charges the batteries to a higher level.

 

I will have to pass over to the experts on that.

[Khayamanzi]

It has been said that running the engine with a 3.5Kw generator is enough load for the engine.

 

 

Thanks for all the advice so far. I am still unclear as to the size of generator I ought to look for being that I'm looking at a portable one, (as opposed to gen set or 240v alternator,) Should I look for one that will absorb all my 240v power requirements or can I get a smaller one which will charge the batteries relatively quickly and will my Mastervolt combi and Adverc cope OK with any generator as a battery charger or not?

[bottle]

Hi Andy

 

Hope we have not confused you too much, the 3.5Kw generator Ernie has on his boat is just like an oversized alternator but 240V.

 

As to the size of generator you need it depends on what you wish to run at the same time, if say you wish to run kettle (1Kw) an electric fire (3Kw) then you would need one of 4Kw. (minimum possibly slightly larger)

 

Do not forget that you will not be running all your items at the same time and if you know the size of the generator you will know the amount of load it will take.

 

For instance if you only had a 3Kw gen. then you would be aware that to have the fire and the kettle on at the same time at least one of the 'bars' on the fire would need to be turned off.

 

Edit typo

Edited May 16, 2006 by bottle

[DHutch]

If you got a 1kva portable, and the mastervolt work flat out in inverter-mode, then i bealve you could theretical draw upto 3.5kva peak. Which i would have though was enought for most things?

- Then when you thortal back a little the combi should start puting back some of what its taken out. right?

- And 1kva is more than enought to power the MV, as long as it doesnt throw a paddy about the quality of the supply...

 

In terms of weather the MV will cope with the supply, you'd have to ask someone who has one, or MV themselfves, i have no experasice on them.

- But as i say, our sterling charger is fine on the Ex1000's output.

 

The tiny little 500/750kva 2-stroke units are mostly to the be the worse, the output of the slitghty larger Kiptor or Honda 4-strokes seam to be good enought for most things, from what ive heard.

- The new models all seam to be "inverting" generators. weather this is good or not i dont know tho!

 

 

Daniel

[Khayamanzi]

Hi Andy

 

Hope we have not confused you too much, the 3.5Kw generator Ernie has on his boat is just like an oversized alternator but 240V.

 

As to the size of generator you need it depends on what you wish to run at the same time, if say you wish to run kettle (1Kw) an electric fire (3Kw) then you would need one of 4Kw. (minimum possibly slightly larger)

 

Do not forget that you will not be running all your items at the same time and if you know the size of the generator you will know the amount of load it will take.

 

For instance if you only had a 3Kw gen. then you would be aware that to have the fire and the kettle on at the same time at least one of the 'bars' on the fire would need to be turned off.

 

Edit typo

 

Thanks for that, yes I guessed Ernie was talking about a 240V alternator - slightly different to my requirements. I suppose I would also need to calculate in the charging ability in addition to any power load I'm putting on it. OK take this scenario! Supposing I have the inverter switched off but the battery charger switched on and a generator plugged in to the land-line socket, My alternators charge at a rate of between 20-50Amps on a bulk charge dropping to about 10-15 on absorbtion and 3-5 on float - How woulda generator compare and what size would I need to be at least equivalent - any maths, techie people have a magic formula??

[bottle]

Andy

 

The generator size will not have any effect on the charging of the batteries that will depend on the 'size' of the charger.

 

The 'load' of the charger should be on it somewhere.

 

I take it we are talking about a 240V generator and a 240v charger.

Edited May 16, 2006 by bottle

[TeeELL]

I am considering buying one of the Honda 'suitcase' models (probably the 2Kva model) firstly because it is,relatively, quiet secondly because it has an economy sensing system and finally because I can run it off bottled gas (with suitable adaptor). I really don't see the point in wearing out the boat engine charging the batteries, other than when I am cruising that is.

[Tommo]

Andy

 

I also have got a Mastervolt 2500 combi and I believe Gary is quite right; they are very fussy about the input from a generator. When I purchased it I was asked if I was going the use a generator, when I answered no, the reply was “that’s OK then as they can cause problems” I suggest you ask Mastervolt, or Keith Meadowcroft of Volt-Master who I notice will be at Crick, if you are going, a good man to speak to about all things Mastervolt.

 

Tommo

[Khayamanzi]

Andy

 

The generator size will not have any effect on the charging of the batteries that will depend on the 'size' of the charger.

 

The 'load' of the charger should be on it somewhere.

 

I take it we are talking about a 240V generator and a 240v charger.

 

 

I am considering buying one of the Honda 'suitcase' models (probably the 2Kva model) firstly because it is,relatively, quiet secondly because it has an economy sensing system and finally because I can run it off bottled gas (with suitable adaptor). I really don't see the point in wearing out the boat engine charging the batteries, other than when I am cruising that is.

Sorry, yes - both are 240V Thanks for the clarification here. I (wrongly it seems,) thought that a higher power generator would charge the batteries faster than a lower power one! I did say I know nothing about this area!!

 

I appreciate all the comments and help and will look and see if I feel I can justify the cost and space now I know the facts!!

 

Cheers once again.

[Tommo]

Andy

 

The generator size will not have any effect on the charging of the batteries that will depend on the 'size' of the charger.

 

The 'load' of the charger should be on it somewhere.

 

I take it we are talking about a 240V generator and a 240v charger.

 

 

Yes it will, the full output of the combi charger is 100 amps! However if you use a

CSCP control panel you are able to adjust the charger consumption to suit the 240v fuse rating.

 

Tommo

[DHutch]

I (wrongly it seems,) thought that a higher power generator would charge the batteries faster than a lower power one!

Assuming the generator is power enought to power the charger, then the any extra power will not speed up the charge.

- If the geneator is not powerfull enough to power the charger, it almost certainly will simply fail to work.

 

However, even really quite a high power/current charger doesnt need much mains to work it.

- A 25amp charger, charging at say 14v, 24*14=350w (about 0.35KVA)

- 50 amp charger is 50*14=700w (0.7KVA) [which incendently at 230v is about 3amps]

- But its unlikely that they will be running flatout for very long at all, unless the batterys are really flat, or damaged.

 

 

 

Daniel

Edited May 16, 2006 by dhutch

[bottle]

Any Charger should the correct size for the battery bank size/type.

 

I have in the back of my mind a figure of 10% of the battery bank as the maximum charging rate, ie 250 amp/hour bank, max charge rate 25amps. but as to the type lead/acid,agm etc I cannot remember. They all vary.

 

I will just have to have a trawl.

[Khayamanzi]

Oh brother!! Just as I thought I was getting things nicely wrapped up!!

[bottle]

Andy

 

We seem to be confusing you even more, lets try to simplyfy it,

 

The amount your batteries are charged is controled by the 'charger'

 

The generator needs to be big enough to run whatever you wish to run, at the same time, whether it is just the charger or any other pieces of equipment.

 

All electrical equipment will have a plate on it somewhere stating its load ( watts or amps) find all of the loads you wish to run at the same time add them up and that is the minimum size of generator you require.

 

If the plates gives the load in amperes (amps) just multiply the amps by the voltage and this will give the watts (5amps*240volts =1200watts=1.2Kw)

[bottle]

Andy

 

Look at it another way your 230volt inlet from a shore-line is rated at 16amp. this equates to 230v*16amps=3680watts=3.68Kw

 

Now its unlikely you will use all of that so the biggest generator you will need is 3.5Kw

[DHutch]

Look at it another way your 230volt inlet from a shore-line is rated at 16amp. this equates to 230v*16amps=3680watts=3.68Kw

Yeah, thats a point!

- I guess if you use a 5/6KVA genset you would need to use more than just a 16amp lead!

 

Also, a lot of marinas have there shore-line sockets fused quite a bit lower. The socket we had use of at anderton was fused at 2amps, with others being fused at 4 or 6. (thats 460w, 920w and 1.380kw respectively)

 

 

Daniel

[Richard Bustens]

10% for lead acid but AGM and some others will charge at up to 90%

 

When he has found a 5K gen set for £500 why not get it the extra will come in usefull, 3.5 will only run a kettle and will not run the charger and a kettle at the same time, the cost is in the gen set and a big one is not a lot more than a small one but the extra will come in handy . Toaster, Kettle, Coffee maker, heaters, Imertion heater, Power tools, Presure washers etc the list is endless.

 

It does not make sense not to fit the biggest you can fit in and afford.