Invertor Use - best practice?

[RichLech]

Interested in how people use their invertors.

 

When motoring during the day, is it best to have the invertor switched on all the time so that 230V is available whenever it is needed, or is it better to run with it off until actually required?

 

Same question for when the engine isn't running eg. in the evening. I am aware that the invertor itself consumes dc power so is it sensible to leave switched off until 230v is actually required?

 

So far, I've left it off until actually required but I'm wondering if it is better for the invertor to leave it on rather than switch it on and off (perhaps) several times during the day.

 

My fridge is 12v so the invertor is used for things like kettle, toaster, charging dyson, wife's hairdryer, tv.

 

How do you do it?

 

 

[atsoft22]

I don't see any point or benefit in having the inverter on unless you need it, unless you have one of the inverter combi's and it needs to be on to charge batteries off shore power.

[Paul C]

I turn it on when I need it and turn it off when I don't need it. If I'm feeling lethargic, it can get left on for some occasions "in between" usage of mains stuff. Definitely off overnight and when I'm not on the boat though. We did have an inverter catch fire, hence its not just for power saving reasons that you might want to switch it off while you're not there (or asleep).

 

The other school of thought is to leave it on 24/7/365, that way it doesn't go through an on/off cycle and it is believed this makes it more reliable. But it would consume more power like that.

[Taslim]

Interested in how people use their invertors.

 

When motoring during the day, is it best to have the invertor switched on all the time so that 230V is available whenever it is needed, or is it better to run with it off until actually required?

 

Same question for when the engine isn't running eg. in the evening. I am aware that the invertor itself consumes dc power so is it sensible to leave switched off until 230v is actually required?

 

So far, I've left it off until actually required but I'm wondering if it is better for the invertor to leave it on rather than switch it on and off (perhaps) several times during the day.

 

My fridge is 12v so the invertor is used for things like kettle, toaster, charging dyson, wife's hairdryer, tv.

 

How do you do it?

 

 

Hi.

 

People who know better than I will be along soon, no doubt, though you are opening quite a can of worms there.

 

So before I become a spectator. It's not quite that simple. (I wish it was) My 2 peneth=

 

Engine running= high loads running, Engine= off light loads only and briefly. Unless you have kit that MUST be on constant 240 switch off.

[Chris Pink]

Indeed the TV is the only one of those I'd run with the engine off (as the dyson might as well be charged when the engine's on)

mmmmm......

 

 

it's no good......

 

Toaster, kettle? On an inverter? You're nuts.

Edited July 4, 2013 by Chris Pink

[deckhand]

Chris, just expand on your comment "your nuts". For all us newbies out there, this is a good opportunity to actually learn why you think its nuts.

[Hawkmoth]

 

Toaster, kettle? On an inverter? You're nuts.

Kettle I agree,(we don't have an electric one) But a toaster is indispensable.

We do run it on the inverter as it makes our toast for breakfast before starting up and moving.

[Ange]

We only use the inverter for the printer (got a 12v tv now) so it only gets switched on when I want to scan or print something.

[Justme]

Toaster, kettle? On an inverter? You're nuts.

 

 

Why?

 

Our toaster is 600watts.

 

Each two slice cycle takes about 2 mins tops.

 

So thats 20wh (1.6ah) per serving.

 

We dont use an electric kettle as we cook on a wood fired range so the kettle goes on that.

[matty40s]

Items like the aforementioned along with the wife,iron,hoover and hair straighteners etc, use high amounts of leccy to either heat up or run motors. Not a problem if the engine is running, indeed you will hear the engine noise change as an iron heats then rests.

However, running these off batteries is a quick way to kill your bank if you do not follow a strict charging regime. (Or have a landline available, then none of this is relevant.

[Ange]

I detest ironing. One of the joys of moving aboard was having an excuse to give up ironing and sport the "crumpled look" forever more

[Kiwidad]

Not to mention how much a bean to cup coffee machine uses!

[Ange]

Not to mention how much a bean to cup coffee machine uses!

Ah but when you come from the land of heavenly flat whites it's a must!

[Chris Pink]

Chris, just expand on your comment "your nuts". For all us newbies out there, this is a good opportunity to actually learn why you think its nuts.

 

Using electricity to heat anything, especially electricity generated on a boat = the most expensive form of power, is highly inefficient compared to burning gas or other fossil fuel or (I know deep down in the swamp they use wood but lets get our toast before 9 huh?)

 

To make toast you need to burn diesel (or even petrol) to make 12v electric to store it in a chemical form to make 12V electricity to convert that to 230V to run your toaster/ kettle to make heat. Each time you lose horrendous percentages of that power. If you simply heat water or toast by burning gas.

 

There is a slight argument that whilst running the engine you may have a surplus if a leisure boat but it's pretty unlikely in any liveaboard regime. Solar just isn't in the running, even the "I've got more than you" boys only have a kilowatt, that will take an 3 hour to boil a kettle of water on a good day.

 

There are a few forum members with all electric boats but they have multi-kilowatt generators to do it with and if you say nothing else about it, it's not efficient.

 

And that's only argument one.

 

A toaster or a kettle is around 3,000W - that's around 300A at 12V, even 150A at 24V to run an inverter. To move that around takes some serious copper and expensive bits of equipment. The cost of a Victron alone to run that lot would probably pay for a cafe breakfast for the next 5 years.

 

 

Yes. Nuts.

 

 

Why?

 

Our toaster is 600watts.

 

Each two slice cycle takes about 2 mins tops.

 

So thats 20wh (1.6ah) per serving.

 

We dont use an electric kettle as we cook on a wood fired range so the kettle goes on that.

 

1.6Ah to make 2 slices of toast?

 

That's around 5% of my daily usage.

 

and you have a large solar array so you are costing less. What's the typical cost of a boat Ah?

 

compared to the almost nothing it costs with gas?

You notice I didn't say anything about the hair dryer or the dyson.

 

You don't have to be a troglodyte to live off grid but you do have to be conscious of what you do use and choose where you spend your power pound (I just made that up, neat huh?)

[Chalky]

A lot depends on what loads you're running and were they factored into your load balance / power audit calculations and use cases.

 

We have an AAA rated mains fridge - to run the fridge requires the 800W pseudo sine inverter to be on. The inverter draws 400ma (0.4A) continuously to run the electronics in it. When running the fridge it draws about 6A however it only draws this for about 20 minutes an hour (on it's lowest setting). The inverter is turned off over night (at about 21:00) and back on the next morning at about 8:00 ish). The fridge is normally turned down to it's lowest setting however when the engine is running (and there's lots of power available) it's turned up to max - it can freeze the milk! This allows us to use the fridge contents as a thermal store/mass and reduce the fridge on time.

When the engine is running then we charge phones etc off the mains supply. Everything else is low current 12V.

We have 400Ah of batteries. The design use case was that with a fully charged battery bank we should be able to go for 2 days without running the engine which is achievable. The batteries then take about 2 hours to bulk (80% soc) charge and then about 6 - 8 to come up to 14.4V - approx 100% soc.

We're a leisure boat so tend to cruise most days, a very different use case to a live aboard.

[nicknorman]

A toaster or a kettle is around 3,000W - that's around 300A at 12V, even 150A at 24V to run an inverter. To move that around takes some serious copper and expensive bits of equipment. The cost of a Victron alone to run that lot would probably pay for a cafe breakfast for the next 5 years.

 

Steady Chris, making your point by exaggerating loses credibility. A toaster is less than 1000w. Most kettles are 2000 to 2200w. Both are on for short periods so use little energy

 

If you are using your boat as God intended (to cruise) then the marginal cost of using electricity, generated when the engine would be running anyway, is comparable with gas and possibly less since there is a lot more wasted heat in both a gas grill and a gas hob.

 

On the other hand if you are using your boat as somewhere to lurk with curtains closed whilst glued to the forum, or something worse on the Internet, and resent every moment you have the engine running to generate power, then gas is probably a better idea.

 

Anyway, regarding the OP's comment we leave the inverter on all day. I do sometimes turn it off on going to bed and restart it on awakening if the batteries are getting a bit low, but TBH I haven't really noticed much difference in the elec consumption either way.

Edited July 4, 2013 by nicknorman

[matty40s]

On that note, if I am on boat it is on, if not, it is off.

[deckhand]

mmm Interesting. We are going to be liveaboards in September so all this is important to us. Looking at televisions just now so need to decide 12v or 230v. We will be in a marina over winter periods but are hoping to get out there from spring onwards. Would you suggest 12 or 230 ?

 

Thankyou for all the other info above , it really does help us newbies. Have no doubt we will learn by our mistakes but don't think that we can avoid listening to experience.

[canals are us?]

mmm Interesting. We are going to be liveaboards in September so all this is important to us. Looking at televisions just now so need to decide 12v or 230v. We will be in a marina over winter periods but are hoping to get out there from spring onwards. Would you suggest 12 or 230 ?

 

Thankyou for all the other info above , it really does help us newbies. Have no doubt we will learn by our mistakes but don't think that we can avoid listening to experience.

Why not a 240volt and 12 volt combi.

 

I have a Cello 22 inch off Amazon that can run on both. Very useful when cruising using 12v and while in a Marina on 240v.

There are other makes like kogan etc.

 

James

Edited July 4, 2013 by canals are us?

[Biggles]

I switch mine on an hour or 2 before we get to the boat to pre chill the fridge and freezer.

 

It remains on until we leave the boat when its switched off again.

Edited July 4, 2013 by Biggles

[nicknorman]

I'm not sure it makes a big difference whether 240 or 12v TV. More important is how long you spend glued to the box, whether its an economical LED TV or an older more power hungry one, and what you feed it with. When we switched from an ordinary Humax Freesat box to a recording HD Freesat box I noticed a significant increase in power consumption. Mind you it is good to be able to pause and rewind live TV for when you miss a critical moment in Eastenders.

I switch mine on an hour or 2 before we get to the boat to pre chill the fridge and freezer.

It remains on until we leave the boat when its switched off again.

Presumably you have to leave the fridge and freezer doors closed. Any problems with mould etc?

[deckhand]

Why not a 240volt and 12 volt combi.

 

I have a Cello 22 inch off Amazon that can run on both. Very useful when cruising using 12v and while in a Marina on 240v.

There are other makes like kogan etc.

 

James

I need to take a look at these, not heard of them but actually sound ideal. I will look into, thankyou

I'm not sure it makes a big difference whether 240 or 12v TV. More important is how long you spend glued to the box, whether its an economical LED TV or an older more power hungry one, and what you feed it with. When we switched from an ordinary Humax Freesat box to a recording HD Freesat box I noticed a significant increase in power consumption. Mind you it is good to be able to pause and rewind live TV for when you miss a critical moment in Eastenders.

 

Presumably you have to leave the fridge and freezer doors closed. Any problems with mould etc?

We have been used to sky here at home but that looks a bit hit and miss on a boat (only get this from what I have read previously) but Freesat sounds interesting. Can you get the other channels (like sky type channels) We don't watch so much during the day but evening we like to have an hour or so. I like crime channels and dramas. (not into any soaps)

[Biggles]

I'm not sure it makes a big difference whether 240 or 12v TV. More important is how long you spend glued to the box, whether its an economical LED TV or an older more power hungry one, and what you feed it with. When we switched from an ordinary Humax Freesat box to a recording HD Freesat box I noticed a significant increase in power consumption. Mind you it is good to be able to pause and rewind live TV for when you miss a critical moment in Eastenders.

 

Presumably you have to leave the fridge and freezer doors closed. Any problems with mould etc?

No we are never away that long. Seldom more than 4-5 days either I'm there or we both are. Indeed Mrs Biggles thinks I do live there and come back to the house to visit. Edited July 4, 2013 by Biggles

[nb Innisfree]

When off grid we keep our Victron Multiplus on 24/7. 230v lighting, tv, 2.8kw instant boiler, food mixer, overhead timevprojector all night plus wifi router on 24/7. Can't be arsed to keep switching on and off for the sake of several ah per day.

[nicknorman]

We have been used to sky here at home but that looks a bit hit and miss on a boat (only get this from what I have read previously) but Freesat sounds interesting. Can you get the other channels (like sky type channels) We don't watch so much during the day but evening we like to have an hour or so. I like crime channels and dramas. (not into any soaps)

Freesat has very similar channels to freeview, but not the Sky channels. I don't see any problem with sky/Freesat vs freeview. With the former, you need a clear view of the sky to the SE, but hedges, trees & tall buildings permitting you can get it anywhere in the country. Freeview is less affected by obstructions but there are chunks of the system where signal strength is too low to get a picture with a modest sized aerial. Since the TV probably has built in freeview, you can do as we do and have the choice between freeview direct from the TV, or Freesat from a separate box, depending on mooring location. We have sky+HD at home and the box gets quite warm (= heavy power consumption) so I would check the power consumption of a normal sky box vs a Freesat box.