Use of inverters on boats?

[Richard10002]

Modern DC-DC converters are vastly more efficient than they used to be, generally not using rectifiers any more, up to 98% efficiency.

Sterling quote up to 85% efficiency with their small inverters and a 0.95a current draw at standby.
Victron do better at 87% - 92% (smaller = less efficient). Standby current for a modest model is about 0.7a

I just looked at the 2 DC-DC converters that power my TV and Soundbar (one for each) and the current with no load is unmeasurable with my monitors. If i turn the soundbar on i see a .95 current draw, coincidently the same as the Sterling inverter uses when it's doing nothing.

and what Sterling quote, when compared with reality, are not necessarily even close to the same. My Sterling inverter charger draws 4A when powering nothing. You can't use the standby mode to charge phones and laptops, the power drawn won't fire it up

 

[PaulRainbow]

and what Sterling quote, when compared with reality, are not necessarily even close to the same. My Sterling inverter charger draws 4A when powering nothing. You can't use the standby mode to charge phones and laptops, the power drawn won't fire it up

That's pretty poor Richard, much worse than the documentation states, have you spoken to Sterling about this ?

 

[sailaboutvic]

An inverter supplying a microwave has to be a proper pure sine wave jobbie else the micro will get annoyed and noisy, won't work.

Not true , I have a 10 year old cheap maplin 3000W inverter and it works my microwave fine also my electric radiator oil fire and my 2000W kettle , but it won't work my induction hob or my AC both are less W then the kettle

 

[sailaboutvic]

I'm looking at replacing my so we can run the 2000w induction hob , as anyone brought one of these non named inverter , Chinese type that does what it says on the tin .

 

[pvb]

I'm looking at replacing my so we can run the 2000w induction hob , as anyone brought one of these non named inverter , Chinese type that does what it says on the tin .

I bought my unbranded Chinese 2000W pure sine wave inverter from Amazon - their return/refund policy is superb. It works fine. I'd steer clear of eBay offers.

 

[rogerthebodger]

I'm looking at replacing my so we can run the 2000w induction hob , as anyone brought one of these non named inverter , Chinese type that does what it says on the tin .

The point about any AC inductive appliance. is that there will ba a high inrush current that may overload the inverter so th inverter will cut out.

This will not apply to resistive appliances like your kettle or heater but your air con has motors so inductive.

 

[sailaboutvic]

The point about any AC inductive appliance. is that there will ba a high inrush current that may overload the inverter so th inverter will cut out.

This will not apply to resistive appliances like your kettle or heater but your air con has motors so inductive.

Hey but microwave still work .
I keep seeing these 3000w /5000w startup on Amazon just like pvb posted just wondered if they would kick in and work the induction hob .
I have to admit when I brought my 3000w from maplin 10 years ago I expected it to last a year for what I paid for it £100 still going strong . But its not P/sine

 

[pvb]

I keep seeing these 3000w /5000w startup on Amazon just like pvb posted just wondered if they would kick in and work the induction hob .

I'd imagine they'd work if you choose one with spare capacity. For example, there's a 3500W (7000W peak) inverter for £350 - https://www.amazon.co.uk/Inverter-Converter-Outlets-Remote-Control/dp/B089GGF3FJ

 

[sailaboutvic]

I'd imagine they'd work if you choose one with spare capacity. For example, there's a 3500W (7000W peak) inverter for £350 - https://www.amazon.co.uk/Inverter-Converter-Outlets-Remote-Control/dp/B089GGF3FJ

Funny that one I been looking at , thanks

 

[pvb]

Funny that one I been looking at , thanks

I can't guarantee it'll work though!

 

[sailaboutvic]

I can't guarantee it'll work though!

Who can ha ha , I might drop them a email

 

[PaulRainbow]

Personally, i wouldn't touch a cheap no-name inverter, especially if liveaboard. I can't imagine how those skinny looking cables they supply can hope to deliver up to 500a !

 

[sailaboutvic]

Personally, i wouldn't touch a cheap no-name inverter, especially if liveaboard. I can't imagine how those skinny looking cables they supply can hope to deliver up to 500a !

Agree about cable Paul , mine I have now came with 4 cables two for each and each cable 50mm sq if I did change I keep the cables I got now .

 

[Kelpie]

If you're considering upgrading to lithium batteries at some point (Vic?) a programmable low voltage disconnect could be an extra line of protection for your batteries. Failing that, one with a higher disconnect than your standard 10v would be good.
Some inverters will also support a remote shut-down which the BMS could trigger. This would save you the expense of a high current relay to do the same job.

 

[pvb]

Personally, i wouldn't touch a cheap no-name inverter, especially if liveaboard. I can't imagine how those skinny looking cables they supply can hope to deliver up to 500a !

You don't have to use the cables they supply; I had some new ones made up. Your "liveaboard" reference is something to think about though. As an occasional user, it doesn't really matter to me if my cheap unbranded inverter dies, but if I were living aboard I'd be mightily annoyed. So there is perhaps a case for spending more if you're a liveaboard. However, a 3000W Victron inverter is about £1200....

 

[sailaboutvic]

If you're considering upgrading to lithium batteries at some point (Vic?) a programmable low voltage disconnect could be an extra line of protection for your batteries. Failing that, one with a higher disconnect than your standard 10v would be good.
Some inverters will also support a remote shut-down which the BMS could trigger. This would save you the expense of a high current relay to do the same job.

I'm taken the relay route so I have control of high and low voltage,
Batteries sitting in Germany should arrive next week I guess with the holiday back log .
But thanks for the imput , can never have too much I put .

 

[PaulRainbow]

I'm taken the relay route so I have control of high and low voltage,
Batteries sitting in Germany should arrive next week I guess with the holiday back log .
But thanks for the imput , can never have too much I put .

If you are going ahead with the Lithium project i'd think very carefully about the rest of your setup. It's worth considering a Victron BMS which could integrate with a Victron charger/inverter, such as a 3000w Multi Plus. It's does cost around £1500, but it's a very sophisticated piece of equipment, which does include low voltage shutdown of the inverter. You need to be extremely careful with an inverter installation, especially with expensive Lithium batteries, unless you are using a very high current relay you can't use it to protect from the inverter depleting the batteries. The highest current relay Victron make is 220a, not enough for a 3kw inverter load. But, you wouldn't need to worry about that with the Victron inverter. Also worth looking at the Cerbo GX and a GX touch 50 display, so you can monitor and control everything.

 

[sailaboutvic]

If you are going ahead with the Lithium project i'd think very carefully about the rest of your setup. It's worth considering a Victron BMS which could integrate with a Victron charger/inverter, such as a 3000w Multi Plus. It's does cost around £1500, but it's a very sophisticated piece of equipment, which does include low voltage shutdown of the inverter. You need to be extremely careful with an inverter installation, especially with expensive Lithium batteries, unless you are using a very high current relay you can't use it to protect from the inverter depleting the batteries. The highest current relay Victron make is 220a, not enough for a 3kw inverter load. But, you wouldn't need to worry about that with the Victron inverter. Also worth looking at the Cerbo GX and a GX touch 50 display, so you can monitor and control everything.

I wish I had that money to keep spending Paul
but have to stop some where , the plain was to keep the inverter we have and run the Gen for the hob if we use it ,
Only used now when in combination with other stuff if we ripening the Gen , other wise we use the gas .
but if I can find an inverter that will run the hob to use on days when we have power to waste it's a route I like to use .

I can't see use useing a 3000w inverter at full power for a starti don't think these Chinese once will run that high and the only reason I would go for a 3000w would be We need one to start the hob up .
I checked it on our Gen and it draws on full power 1200 w at 240v so that about 100A at 12v if my sum right Running that for half an hour when our batteries are up I guess will be fine and then there always the gas to full back on plus ere the Gen too .
I only plain to run large load when we have power to waste but it be ashame to spend all this money on lithium and waste power when we can use it else where and cut down on fuel and pollution.

BMS will be our last protect, I be the first as I be keeping an eye while we are running large loads which is what I do now .
In between the BMS and Me I setting up some very load alarm to warn me when the batteries are near the knee 20% and 90% .

 

[PaulRainbow]

I wish I had that money to keep spending Paul
but have to stop some where , the plain was to keep the inverter we have and run the Gen for the hob if we use it ,
Only used now when in combination with other stuff if we ripening the Gen , other wise we use the gas .
but if I can find an inverter that will run the hob to use on days when we have power to waste it's a route I like to use .

You know your budget better than i

I can't see use useing a 3000w inverter at full power for a starti don't think these Chinese once will run that high and the only reason I would go for a 3000w would be We need one to start the hob up .

Yes they do go that high and more.

I checked it on our Gen and it draws on full power 1200 w at 240v so that about 100A at 12v if my sum right

You need to make an allowance for the inefficiencies, rule of thumb is divide AC watts by 10 for DC amps, so that'll be 120a

Running that for half an hour when our batteries are up I guess will be fine and then there always the gas to full back on plus ere the Gen too .
I only plain to run large load when we have power to waste but it be ashame to spend all this money on lithium and waste power when we can use it else where and cut down on fuel and pollution.

120a for an hour is a hell of a lot of current draw.

BMS will be our last protect, I be the first as I be keeping an eye while we are running large loads which is what I do now .
In between the BMS and Me I setting up some very load alarm to warn me when the batteries are near the knee 20% and 90% .

Just be careful with those expensive Lithium batteries Vic, given that you hold the forum record for killing Trojans

 

[Garold]

I’m no techie, but as far as I remember we have 350ah batteries, a 2000w inverter and a 4.5kw genny. On a 38foot yacht.

We use the microwave or kettle or charging for laptops/phones etc as we sail, with just the inverter. Then, in the evening, when we are cooking, we use the genny for about 40 mins so that any extended or multiple use of the above, is possible. Also, any extra power at that time goes into charging the batteries. And if not enough else is running to use the genny kw, water heating.

When we are on shore power we use everything including hot water heating whenever we want.

Except for 2020, we have been 6months on board each year for the last 5 years. We had to renew our batteries at about 3.5 years. I’m not sure if our usage shortened the life of our batteries but most people reckoned that with our usage the battery life was average.