Inverter Recommendations?

[Nattysw]

Hi all! So currently myself and my partner are hooked up to shore power and we've not ventured out, but we're planning on going full time travelling later in the year so need to prepare! We recently had 4 new leisure batteries fitted with a victron charger and we'd like to fit an inverter for using the 240V. In our boat the lights, fridge and water pump run on the 12V, so we're mostly only looking to charge devices, toaster, kettle (though we can put one on the hob and use gas) and the TV. We also have a record player and a pretty hefty collection though we prepared to lay off the records whilst we're not hooked up! Does anyone have any good recommendations for an inverter that suits our system? Thanks in advance! 

[Alan de Enfield]

Before you decide on the Inverter you need to decide on by what method you are going to charge to batteries to replace what is being used (you have very heavy consumption devices - toaster and kettle - so will need to do a full electrical audit)

 

You can replace the electricity either by running the engine for (maybe) 4+ hours per day, or you can run a generator and power the battery charger for several hours per day.

 

If your boat electrical system is not geared around an inverter you may need to make some 'adjustments / alterations' to what you have. Basically you need to look at "is your system suitable for an inverter", rather than buying an inverter "suitable for your system".

Edited February 28 by Alan de Enfield

[Nattysw]

We're planning on running the engine to power the batteries as we're wanting to keep on the move! Our boat electrics are definitely not geared around an inverter and we're new to boating in the last year so will ing to bend however we need to to make it work (for example cut out the toaster and kettle and use the oven for both). The only non negotiable is charging my laptop as I work remotely, though it would be nice to meet in the middle!

[Tony Brooks]

1 minute ago, Nattysw said:

We're planning on running the engine to power the batteries as we're wanting to keep on the move! Our boat electrics are definitely not geared around an inverter and we're new to boating in the last year so will ing to bend however we need to to make it work (for example cut out the toaster and kettle and use the oven for both). The only non negotiable is charging my laptop as I work remotely, though it would be nice to meet in the middle!

 

You do know that you can get car (12V) computer power supplies and 12V USB sockets for phone charging etc. The only problem with the computer is that some makers use a fancy power supply, lead and plug that excludes you using a generic 12V power supply. Most 12V supplies seem to come with a set of interchangeable plugs for the computer end. No point in wasting electricity converting 12V to 240V via and inverter and the 240V back to about 20V ish for the computer, each conversion wastes electricity.

[IanD]

4 minutes ago, Nattysw said:

We're planning on running the engine to power the batteries as we're wanting to keep on the move! Our boat electrics are definitely not geared around an inverter and we're new to boating in the last year so will ing to bend however we need to to make it work (for example cut out the toaster and kettle and use the oven for both). The only non negotiable is charging my laptop as I work remotely, though it would be nice to meet in the middle!

There's a massive difference between powering low-power devices like a laptop (dead easy and cheap) and high-power ones like toaster/kettle (much harder and more expensive) -- and not just powering them (inverter) but where you get the energy from to recharge the batteries. If you're on the move all the time (hours per day) then recharging from the engine is fine, if you're moored and have to run the engine for hours per day that's not so good. At least in summer solar panels are an excellent and relatively cheap way to provide power nowadays, but they're not much use in winter.

2 minutes ago, Tony Brooks said:

 

You do know that you can get car (12V) computer power supplies and 12V USB sockets for phone charging etc. The only problem with the computer is that some makers use a fancy power supply, lead and plug that excludes you using a generic 12V power supply. Most 12V supplies seem to come with a set of interchangeable plugs for the computer end. No point in wasting electricity converting 12V to 240V via and inverter and the 240V back to about 20V ish for the computer, each conversion wastes electricity.

On most laptops the DC input from the mains adaptor isn't 12V, 20V or so is more usual. Doesn't mean you can't use an external DC-DC supply but care is needed. Many modern laptops now use USB-C for both power and external connections, any 12V-to-USB-C power supply with high enough rating will then do.

[Alan de Enfield]

2 minutes ago, Tony Brooks said:

 

You do know that you can get car (12V) computer power supplies and 12V USB sockets for phone charging etc. The only problem with the computer is that some makers use a fancy power supply, lead and plug that excludes you using a generic 12V power supply. Most 12V supplies seem to come with a set of interchangeable plugs for the computer end. No point in wasting electricity converting 12V to 240V via and inverter and the 240V back to about 20V ish for the computer, each conversion wastes electricity.

 

That's how I power my 19 volt Acer laptop.

 

Plug into the boat 12v system (cigarette lighter socket) and the other end outputs 19v - 20v and powers the laptop.

 

Simples !

 

[Nattysw]

I definitely will look into 12V car charger for my laptop then for efficiency! My laptop charger takes 240V and outputs 20.3V so I will need to check that's ok. Though we only have one 12V socket in the living space (also our TV is 240V amongst other things) so I'm conscious I probably will still need an inverter as well.

[Tony Brooks]

2 minutes ago, Nattysw said:

I definitely will look into 12V car charger for my laptop then for efficiency! My laptop charger takes 240V and outputs 20.3V so I will need to check that's ok. Though we only have one 12V socket in the living space (also our TV is 240V amongst other things) so I'm conscious I probably will still need an inverter as well.

 

Are you sure the TV is 240V? Many nowadays use a wall wart type plug that converts the 240V to something around 12 to 20V to power the TV. If yours is like this then a C to DC converter will run it from 12V. If the TV runs on 12v be a bit wary abut cutting the plug off and fitting one suitable for you 12V socket because the 12V system can run at close to 15v and suffer surges so a TV expecting a steady 12V might turn its toes up after a while.

[nicknorman]

Blimey the luddites have got in first while I wasn't looking! I would get a Victron inverter, they seem to be the best bet at the moment. In terms of what size, you need to look at the most powerful device you plan to use. For example a toaster is probably under 1000 watts, whereas an electric kettle is more likely 2000 to 3000 watts. If you are looking at something with a motor, be aware that the initial surge of power required to start the motor, can be a lot more than the continuous power consumption. Sometimes as much as 5 or 10 times as much!

 

You do have to be careful about how much power you take out of the batteries, and all the power you take out has to be put back, but as well as looking at the power consumption you also should look at the duration that device will be on. So for example a toaster, although using a fair bit of power, is only on for a couple of minutes, so the amphours taken from the battery is not that much. Same for the kettle, although the amphours will be more because it takes twice as much power and is probably on for longer. One solution to this is to only use these "thirsty" devices when the engine is running (and running a bit above idle). So it is fine to use the kettle while you are cruising, not a good idea to use the kettle in the evening when you are moored.

 

The other thing is that with all this ability to use lots of power, it becomes more important to keep track of the state of charge of the batteries and to make sure they get fully charged regularly, otherwise you can kill them in a few months. I would recommend getting some sort of battery monitor fitted eg a BMV712 or a Smartgauge.

 

Once you have the inverter and it is wired to the batteries with short fat cables, you will need to work out how to connect it to your boat's mains sockets etc. The rules are that you must not be able to have the inverter and the shore power connected at the same time, and the short socket must not be live when the inverter is on. So you need a mains changeover switch that is "break before make" ie when you move the switch, it disconnects the one source before connecting the other source.

[cheesegas]

46 minutes ago, Nattysw said:

I definitely will look into 12V car charger for my laptop then for efficiency! My laptop charger takes 240V and outputs 20.3V so I will need to check that's ok. Though we only have one 12V socket in the living space (also our TV is 240V amongst other things) so I'm conscious I probably will still need an inverter as well.

Either do it yourself or get some more 12v circuits added, it'll greatly reduce power consumption as you can fit USB A or C sockets to charge devices, and also charge your laptop with a 12v laptop adaptor.

 

I highly highly recommend not buying the cheapo universal 12v laptop chargers on ebay/amazon as they tend to run very hot and can be extremely electrically noisy which puts strain on the DC power supply inside your laptop. Most major manufacturers will sell a car charger for their laptops which is more expensive but better made and won't void the warranty. If you have a big 15" laptop though, check that your 12v wiring is up to the task; the laptop charger could draw around 10-12a, and if your wiring is too thin it'll overheat. More of a problem on older boats.

 

If you have 500W+ of solar, you'll generally find that power is plentiful in the summer but if you go off grid in the darker months you'll need to run the engine.

 

Fit a battery monitor like a Victron Smartshunt or BMV before the inverter ideally, so you can keep track of the battery state of charge, and get some idea of how much energy you need to put into the batteries to replace what you've used. General rule is to avoid using anything with a heating element in it unless the engine is running; exceptions are if you have lithium batteries (which I doubt you do) or if you have lots of solar and the sun's out.

 

What record player is it? Older ones have an AC synchronous motor which can be sensitive to some inverters and either run too slow or not at all. Newer ones generally have a DC motor powered by an AC to DC converter which means they're not that sensitive.

[blackrose]

18 hours ago, Nattysw said:

...so we're mostly only looking to charge devices, toaster, kettle (though we can put one on the hob and use gas) and the TV. 

 

Yes, put a kettle on the hob and use gas. Why would you want to use your batteries to boil water? - unless the engine happens to be running and the batteries are being charged I suppose.

 

17 hours ago, cheesegas said:

Either do it yourself or get some more 12v circuits added, it'll greatly reduce power consumption as you can fit USB A or C sockets to charge devices, and also charge your laptop with a 12v laptop adaptor.

 

I don't bother and just run the laptop from the mains as my inverter is on all the time anyway to run the mains fridge. I work from the boat so the laptop is on all day and often half the evening, but it hardly uses any power as it is, so I can't see I'd be saving very much if I ran it from 12V? Is it really worth it for me when the inverter is on anyway? I can't remember which make and model of laptop it is offhand as I'm away at the moment and it was given to me by my company, but it's a very recent model. I thought designers made everything as energy efficient as it could possibly be these days, so I'd be surprised if there was some glaring inefficiently at the point where 240v becomes 20v as Tony says. Is that really the case?

 

On the subject of leaving the inverter on all the time, one of my neighbours told me I'd made a mistake buying a mains fridge because even though it's energy efficient I hadn't taken the inverter's quiescent load into account so I was wasting battery power having the inverter on 24/7. Well, my inverter uses 0.6A x 24 hours = 14.4 Ah ÷ 2 because the thermostat only turns it on for about half the time. So that results in about 7 Ah/day. That's hardly worth worrying about and to me it certainly seems justified given the not insignificant cost of a decent 12v fridge. 

Edited February 29 by blackrose

[IanD]

10 hours ago, blackrose said:

 

Yes, put a kettle on the hob and use gas. Why would you want to use your batteries to boil water? - unless the engine happens to be running and the batteries are being charged I suppose.

 

 

I don't bother and just run the laptop from the mains as my inverter is on all the time anyway to run the mains fridge. I work from the boat so the laptop is on all day and often half the evening, but it hardly uses any power as it is, so I can't see I'd be saving very much if I ran it from 12V? Is it really worth it for me when the inverter is on anyway? I can't remember which make and model of laptop it is offhand as I'm away at the moment and it was given to me by my company, but it's a very recent model. I thought designers made everything as energy efficient as it could possibly be these days, so I'd be surprised if there was some glaring inefficiently at the point where 240v becomes 20v as Tony says. Is that really the case?

 

On the subject of leaving the inverter on all the time, one of my neighbours told me I'd made a mistake buying a mains fridge because even though it's energy efficient I hadn't taken the inverter's quiescent load into account so I was wasting battery power having the inverter on 24/7. Well, my inverter uses 0.6A x 24 hours = 14.4 Ah ÷ 2 because the thermostat only turns it on for about half the time. So that results in about 7 Ah/day. That's hardly worth worrying about and to me it certainly seems justified given the not insignificant cost of a decent 12v fridge. 

 

If you've got gas on the boat it's a lot cheaper (and quieter) to use that for cooking instead of electric charged by an alternator which means running the engine.

 

Do you mean your thermostat turns the inverter on and off? Surely it turns the *fridge* on and off? The inverter no-load power is drawn 24h a day unless you turn the mains off...

 

But I agree that with decent modern inverters the no-load draw is usually small enough to be ignored -- at least, unless you've got a honking great big one like mine (60W no-load)... 😉

Edited February 29 by IanD

[doratheexplorer]

Honestly,  if I was doing it all again, I wouldn't bother with an inverter at all.  I'd run all my regular stuff off 12v (laptops, tv, fridge etc).  Don't use electricity to run anything which produces heat (so use the hob/grill for kettle and toast).  I'd have a generator for the occassions when I really need to run 240v (power tools, washing machine), and that way I'd have another way to charge my batteries in case of engine issues.  A reasonable quality genny is cheaper (for the same power) than a reasonable quality inverter.  Doing it this was will also put less strain of your batteries, so they'll last longer, saving you even more money.

 

To the OP, it's not until you go cruising permanently, that you'll realise just how important it is to minimise electricity consumption.  Until you do, repeatedly wrecked batteries will be the order of the day.  Also, get solar panels fitted.

[Tony Brooks]

2 minutes ago, doratheexplorer said:

Honestly,  if I was doing it all again, I wouldn't bother with an inverter at all.  I'd run all my regular stuff off 12v (laptops, tv, fridge etc).  Don't use electricity to run anything which produces heat (so use the hob/grill for kettle and toast).  I'd have a generator for the occassions when I really need to run 240v (power tools, washing machine), and that way I'd have another way to charge my batteries in case of engeine issues.  A reasonable quality genny is cheaper (for the same power) than a reasonable quality inverter.  Doing it this was will also put less strain of your batteries, so they'll last longer, saving you even more money.

 

To the OP, it's not until you go cruising permanently, that you'll realise just how important it is to minimise electricity consumption.  Until you do, repeatedly wrecked batteries will be the order of the day.  Also, get solar panels fitted.

 

Watch out, @nicknorman will be along to call you a Luddite because you don't need, or want, all the fripperies of a floating cottage. I agree with you. Especially the implication of getting solar before an inverter.

[doratheexplorer]

3 minutes ago, Tony Brooks said:

 

Watch out, @nicknorman will be along to call you a Luddite because you don't need, or want, all the fripperies of a floating cottage. I agree with you. Especially the implication of getting solar before an inverter.

I'm not saying Nick's wrong, it's just that I think a newish boater would do better by going down the simple route.  Nick's set up is, I'm sure very impressive, but it's also complex and requires considerable understanding to use it in the best way.  It's also very expensive, and I'm not sure a cost-benefit analysis would support the necessary investment.

[Rob-M]

We use an inverter for powering our router, TV, media streamer, laptop, phone\tablet chargers, hairdryer and DAB radio as it is easier to just plug those things in with the supplied cable.  I do switch the laptop charger on and off throughout the day though to preserve the laptop battery.

 

Having solar installed made a massive difference and enables us to go throughout the summer only running the engine to move the boat.

 

I do use gas for the kettle and for making toast though.

[nicknorman]

20 minutes ago, Tony Brooks said:

 

Watch out, @nicknorman will be along to call you a Luddite because you don't need, or want, all the fripperies of a floating cottage. I agree with you. Especially the implication of getting solar before an inverter.

Luddite!

Just joking, but I think one should perhaps bear in mind the question being asked "which model of inverter do I need" rather than a different question "do I need an inverter at all". The answer to the latter question is of course no. We spent 20 years borrowing a friend's boat to go boating for a 2 week holiday every year. It didn't have an inverter.

But, these days lots of people do have an inverter. Times move on! And if you have an inverter, there is of course no complusion to turn it on! It is helpful to answer the question asked rather than answering a question not asked.

 

On Mike (Blackrose's) point, having a good inverter and a mains fridge is a perfectly valid alternative to a 12v fridge. The 12v fridges around at the moment seem to be very low budget (and hence low efficiency) mains fridges that have had a 12v compressor added. So if you look at the overall efficiency of a 24/7 quality inverter and a modern high efficiency mains fridge, vs a 12v fridge, there is not much in it and with the former you have the advantage of always-on mains power in the boat.

22 minutes ago, doratheexplorer said:

I'm not saying Nick's wrong, it's just that I think a newish boater would do better by going down the simple route.  Nick's set up is, I'm sure very impressive, but it's also complex and requires considerable understanding to use it in the best way.  It's also very expensive, and I'm not sure a cost-benefit analysis would support the necessary investment.

Well yes but we had an always-on inverter right from the start, when we had ordinary Lead Acid batteries.

[cheesegas]

11 hours ago, blackrose said:

Yes, put a kettle on the hob and use gas. Why would you want to use your batteries to boil water? - unless the engine happens to be running and the batteries are being charged I suppose.

 

27 minutes ago, doratheexplorer said:

Honestly,  if I was doing it all again, I wouldn't bother with an inverter at all.  I'd run all my regular stuff off 12v (laptops, tv, fridge etc).  Don't use electricity to run anything which produces heat (so use the hob/grill for kettle and toast).

The advantage of using an induction hob and electric kettle is that you don't need to use gas in the summer months to boil water and cook. With the correct setup - a modest amount of lithium battery capacity and around 1kw of solar, you can cook mostly with electricity for a good 6 months of the year without having the run the engine to charge the batteries. A 13kg gas bottle now lasts me around 8 months as it's only used to cook in winter and for the instant water heater. Not a massive money saver but the convenience of not having to change the bottle and using an electric kettle is nice.

 

I do however agree that if you're new to being off grid, the general rule of not using electric heating things is good to stick by!

 

My alternator is switched off in late April until the solar gets less in Oct. Looking at re-doing the kitchen with a 2 burner gas hob and a 1 ring induction hob for year-round cooking, to replace the usual 4 burner + oven stove I have at the moment.

[MtB]

6 minutes ago, cheesegas said:

Looking at re-doing the kitchen with a 2 burner gas hob and a 1 ring induction hob for year-round cooking, to replace the usual 4 burner + oven stove I have at the moment.

 

How on earth will you cook a Sunday roast with all the trimmings, with no oven?!! 

 

 

[IanD]

39 minutes ago, doratheexplorer said:

I'm not saying Nick's wrong, it's just that I think a newish boater would do better by going down the simple route.  Nick's set up is, I'm sure very impressive, but it's also complex and requires considerable understanding to use it in the best way.  It's also very expensive, and I'm not sure a cost-benefit analysis would support the necessary investment.

 

People build and install things on boats -- and everywhere else -- for lots of reasons, not just cost-benefit. Why have an expensive trad engine when you can have a cheap secondhand modern diesel? Why pay the extra for a hull from one of the premium builders and fit it out expensively when you could get something superficially similar from a cheapo builder? Why have an inverter at all when you can make do with much less electrical "stuff" on board, if that suits your lifestyle? Why have an expensive comfy sofa or bed when you could have a much cheaper one?

 

A modern electrical setup with things like LFP batteries/inverter/solar/big alternator+controller/generator does cost a lot more money than a "traditional" narrowboat one with a few LA batteries, but means you can treat the mains more like in a house with whatever appliances you want -- but in the end it's a matter of convenience/preference, not absolute necessity. If you don't want to do this or can't afford it, then stick with "traditional" electrics, neither approach is "wrong" or "right".

 

Going the whole hog with massive LFP batteries/inverter/generator just to get rid of gas for cooking really doesn't make sense on a conventional diesel boat due to the cost; the reverse is true on an electric/hybrid (like mine) where all this exists anyway as part of the propulsion system, but there are only a tiny number of boats like this on the canals today due to the very high up-front cost... 😉

 

 

Edited February 29 by IanD

[MtB]

(Or a birthday cake for the GF, even?)

 

 

That's weird. Has 'post merging' just been turned off?

 

 

[cheesegas]

1 minute ago, MtB said:

How on earth will you cook a Sunday roast with all the trimmings, with no oven?!! 

Just now, MtB said:

(Or a birthday cake for the GF, even?)

I like to cook but I've found I rarely use the oven...it's used for the occasional pizza from Tescos when I'm feeling lazy and that's it. Must be a good couple of months since it was last on. In winter, I do casseroles and baked potatoes on the woodburner, and in summer I have a little airfryer which heats up the boat less than the oven!

[nicknorman]

4 minutes ago, MtB said:

 

How on earth will you cook a Sunday roast with all the trimmings, with no oven?!! 

 

 

Air fryer.

[MtB]

1 minute ago, nicknorman said:

 

Air fryer.

 

 

Fried beef and Yorkshire pudding. DELICIOUS!

[cheesegas]

5 minutes ago, MtB said:

Fried beef and Yorkshire pudding. DELICIOUS!

Not sure why they call it an air fryer as it's more like a really tiny fan oven. Mine's definitely too small for more than a couple of Yorkshires but it makes a cracking roast beef in half an hour. Uses about 40ah which is replaced in less than an hour in summer, but if I fitted a bigger MPPT it would probably come mostly from solar directly. In winter it's stovetop casserole beef though!

Edited February 29 by cheesegas