What size inverter?

Whitelighter

Whitelighter

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So I am thinking about an inverter for the new boat. I dont really need a genny as the cooktop, oven and heating are diesel powered, the TV's and fridges are 12v and there is not that much other kit I have on board. That said, I would like the option to run mobile phone charges, brew a cup of tea and have the option to use a couple of oil filled radiators as I dont like leaving the eber type systems on when not on or near the boat (but I do like it abit toatsy when I come back from the pub).

I guess the biggest draw would be the rads, but the oil filled only really trickle the heat in and then turn off. What size inverter should I be considering? I have seen some advertised as pure sign, id this important or not?

ta
 
I would only go for a pure sinewave inverter. Size is just a case of summing up the wattage that you want - plus a little extra. You'll need more headroom if there are any inductive (motor) loads.

Oil filled radiators can be hungry - I have a small one in my office and its 1500watts. A kettle will be quite hungry too, so I guess you're looking at a 2.5kw inverter and that probably couldn't run the rads and a kettle at the same time. You'll need to size the battery bank to suite as well....

Rick
 
Thanks Rick - I wouldn't be running the rads with anything else, they are for use when we are not on the boat. I take your point about the pure sinewave inverter so will look for one of those.

Battery bank I think is ok - the boat has 6 in total, 2 engine and 4 domestic. Not sure of the size, but they are pretty big/powerful.

Any ideas on the best makes to look at?
 
If you're specing the boat from scratch - maybe look at a combined charger/inverter like the Victron unit. Mastervolt are good (used their kit throughout the Elling). Or there are a tonne of no-brand sinewave units that probably do the job just fine.

Rick
 
As far as I can tell, sinewave is important for running more hi-tech equipment such as lcd-tv, laptops, playstations, etc. Charging a mobile would probably be ok from a non-sinewave unit.

Still, I would (and am going to) go for a sinewave although they are more expensive.

Using a kettle or a 1500 watt radiator is going to be heavy on the batteries (tried that).

Also, efficiency on inverters is only ~90% so take that into account as well.
 
Yep, and as soon as some progress is made at the factory I promise to cover the forum in lots of questionably commerical build pics!!!!! /forums/images/graemlins/blush.gif /forums/images/graemlins/blush.gif /forums/images/graemlins/blush.gif

It may be for the business, but I am paying for the damn thing and as far as I am concerned it will be my boat so getting quite excited now.
 
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I would only go for a pure sinewave inverter.

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Yep definately a sinewave one - dont cut corners here.
I built a PC into the sailing club's committee boat and someone had bought one of the cheap very square wave inverters.
Some laptops worked some didnt work at all and the system I was trying to put in didnt have a chance but it goes to show that you dont want this type of equipment to fail for the sake of a few quid.
 
For all the loads you mention you do not need sine wave. You would be fine with a much cheaper non sine-wave. As folks have said, you need pure sine wave for a laptop, but you didn't mention a laptop and a laptop will have a couple of hours of its own battery anyway. So why not save £££ and get a non sine wave job?

You will need pretty chunky 12v wiring for a 1500w inverter, as it will be 125 Amps plus on the 12v side, which is like starter-motor style cabling that must be connected back to the high-current breaker panel (where the BT and winches are connected to) not the ordnary low-current breaker panel where all your lights and fridges are connected.

Also i wouldn't leave 1500w running off a 12v inverter while at the pub. 24v maybe, but not 12v. It is much safer to leave the Eberspacher running. The Eber is designed to run continuously for hours. A pukka inverter might run ok but I'd want 200% confidence in my electrical installer and I'd want to know he had sized the cables for continuous duty and hadn't inadvertently caused any hotspots in them where they pass thru panels or are otherwise insulated/jacketed. And even then I'd be very concerned about leaving 100amps DC running thru cables for a couple of hours unattended. That is 100x the fire risk of an Eberspacher, imho. And it will shag your batteries anyway.
 
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So why not save £££ and get a non sine wave job?

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Assuming that this is also a demo boat, I'd be tempted not to skimp on things like that. You never know when a customer is going to want to charge their laptop or god knows what whilst on a demo...

Rick
 
Hi Kipper,

I hadn't thought of that but would like some more info. The boat is on a marina, but I really dont want to be marina dependant. I like being on the hook or on a bouy in places like Alderney when using the boat and Mrs. Banks insists on life's little luxuries remaining intact /forums/images/graemlins/grin.gif

The last boat had an eber, but I found that it wasnt always pleasant sleeping with the system on as it makes the cabin very dry, plus I never felt i could leave it on when down the pub away from the boat. It is nice to come back to a toasty warm boat /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

I want some form of heat other than the eber which the boat also has, and is useful for heating the cocnpit which is where the galley and saloon is any way.

cheers

Jez
 
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plus I never felt i could leave it on when down the pub away from the boat

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Your choice ofcourse, but we've left the eber on numerous times while away for a dinner. As it also has a weekly timer and an option for a remote control, I assume it safe to leave it on. So personally don't see a risk in leaving it on. Besides if worse comes to worse it's better to be at the pub than in the front cabin /forums/images/graemlins/cool.gif

Or do you have some other reason for not leaving it on?
 
Jezz regarding the Dimplex heaters, You can get them from most Swindlery sites but I got mine from a Euronics ( i think thats how you spell it) electricl store and they were £60 for the pair. When i leave the boat i just leave them on low setting and as they have a built in thermostat they switch on and off as reuired.

Glad to be of some use.

Gary
 
Have you got a piccie of what you have? I went on the dimplex site and they seem to do either oil filled or fan heaters. Dont want a fan heater as they are seriously dangerous, and I cant see any difference between a normal oil rad and the dimplex.

Or am I missing something? Webby here
 
I have a 2Kw and runs the 2.5Kw kettle although I am going to get a smaller kettle to take the pressure off.
I too use an Eber when away from the boat for an evening. I can't see it setting the boat alight and don't know of any instances where this has happened.
My Victron inverter charger is excellent for both power and charging.
 
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