INVERTERS

[Guest DAYTONA-BILL]

Hi all, would anybody know if a 150w or even a 300w plug in inverter (with a ciggy lighter socket plug) would be ok to use on a ciggy lighter socket on a hire boat?. Do they have to have a minimum safe wattage limit, and if so, what is is it. I`ve been looking at low powered inverters of 150-300watts for Karen to plug in her hair staighteners. I`m also looking at the power lead with sockets and circuit breakers option, which for this year, w44nty has very generously offered to loan me his. I`m pretty sure these small inverters are man enough to power a small DVD player and phone and camera battery chargers, but are they man enough for a pair of hair straighteners?. Looking on the hair straighteners, it reads 110-120 60hz 47w, and 220-240 50/60hz 47w. Does that mean they draw 47 watts at 220-240 volts. Also, i`ve read elsewhere that some inverters are not nessecarily the right type of wave for whatever, what type of wave should it be to run a set of hair straighteners, and a small DVD player?. I now wish i`d payed a lot more attention when i did electronics at school . Regards to all ..................... Neil.

[petersjoy]

Hi Neil, As far as hair straighteners go my daughter's tried hers on the boat, i've got 3 150w inverters and an 800w too and none of them power her tongs.

The 150w ones have no problem with phone chargers laptops or a 19" tv/dvd player. The cheap 800w one will run Lorna's haidryer on med settings.

Hope that explains a bit.

[Antares_9]

Paul is dead right on the lack of capacity for anything producing heat from smaller inverters Neil. As for whether the installed DIN lighter socket would support an inverter the answer is nobody can say, though it should have a minimum rating there is no way of knowing (without inspecting it or a detailed wiring diagram) what cabling size is used or what length of cable which all determine the actual draw that can be safely taken, and for a decent size inverter that is pretty heavy cable.

[Guest DAYTONA-BILL]

chaps, at least we`ll be able to use the small DVD player if it`s pouring down. I suppose the next option is the 12 volt straighteners from the caravan suppliers, though i would imagine they`re as effective as the 12v hair dryers. Thanks anyway gus. Regards ............. Neil.

[Hockham Admiral]

Neil, Hi

47watts is 47 watts whatever the voltage... at 12V it's 4 Amps so the inverter should cope.. but you will be able to use the shore power cable we all talked about recently?

[Antares_9]

As you say John, Wattage is Wattage, but that is somewhat irrelevant without the rest of the story and for installation and usage of appliances onboard.

For example, divide load watts by actual battery voltage, this will be in the range 12-14V (24-28V). Then to allow for inverter efficiency, typically 85%, divide the figure by 0.85. Thus:

For a 300W load at 12V….300 ÷ 12 ÷ 0.85 = 29.4 Amps.

For a 300W load at 14V….300 ÷ 14 ÷ 0.85 = 25.2 Amps.

Close to 30 amps is being drawn just for a 300 watt load, that would flatten a 100 ah battery to it’s useful level in about 2 hours or less. The cable size to obtain a 3% drop (otherwise the voltage would drop and the amperage draw would rise further) would be quite large indeed. Even if the inverter was 15 feet away from the battery bank it would require 35sq mm cable.

A 12v dc 400w appliance similarly placed in relation to the battery bank would require 50sq mm cable to ensure a 3% voltage drop.

Even to draw your 47 watts from an outlet, let’s assume it’s on the dash panel about 20 feet from the battery bank in cable run terms, it would still require 10 sq mm cabling.

[Guest]

As has now been well pointed out, the thickness of cables feeding inverters is quite a surprise to most people when they first see them. On a 750watt inverter they are like car jump leads, with huge croc clips to match.

Even if hire boats do have heavy feeds to 12v Cig sockets, (and hopefully an appropriate backing fuse or breaker), what are the actual plug and sockets rated at ? Agreed, when they were first designed for lighting cigarettes, they carried a fair current, but that was momentary, till the element glowed and they popped out. The spade terminals on the back of them can't carry that much anyway.

[Guest DAYTONA-BILL]

Neil, Hi

47watts is 47 watts whatever the voltage... at 12V it's 4 Amps so the inverter should cope.. but you will be able to use the shore power cable we all talked about recently?

Hi John, yes i know what you mean, but i`m thinking about if we moor somewhere out of the way, which we sometimes like to do. For this scenario, a decent invertor would be a great help, but it looks like it`s a no goer for a ciggy lighter socket as they`re too powerful for the boats circuitit`s, so it looks like it`s going to have to be plan b, and getting hold of some 12v ones especially designed for use in ciggy lighter sockets.Going on holiday used to be so simple years ago . Regards to all .................... Neil.

[Antares_9]

Take yourself a little Honda genset along Neil (or possibly one a bit louder), you can rent them for bus fares and it's probably worth the reduction in earache from 'er indoors and just think of the annoyance you can cause at quiet mooring spots.

[Hockham Admiral]

Take yourself a little Honda genset along Neil (or possibly one a bit louder), you can rent them for bus fares and it's probably worth the reduction in earache from 'er indoors and just think of the annoyance you can cause at quiet mooring spots.

Or tell her you love her with frizzy hair!

[Antares_9]

Or tell her you love her with frizzy hair!

What was the cold war slogan, oh yes "Duck and Cover" I guess you could substitute "natural" for "frizzy" but I wouldn't even risk that personally.

[Guest DAYTONA-BILL]

Or tell her you love her with frizzy hair!

That`s just it John, i DO prefer to see her with wavy/curly hair, as it suits her much better. She had it when we first met (8 years ago), and i thought she looked lovely then too (as well as now). But she won`t listen to me, but then women never do listen to men do they . God am i going to get stick for that?.

[Hockham Admiral]

Neil, "Trust Me!"

I won't say a word about her hair..... frizzy or not..........

[goodall_m1]

But she won`t listen to me, but then women never do listen to men do they . God am i going to get stick for that?.

Neil, after eight years you should have realised the Women ALWAYS listen to what men say,

it is just that they then decide whether or not they wan't to ignore it or not.

Mention spending money on something for them and "BING", mention the possibility of buying a boat and ... silence.. she wasn't listening.

Try it, just mention that little blonde bit that you have on the side down in Ringwood and see if she notices it..

[Guest DAYTONA-BILL]

OK, one 150 watt inverter bought, as well as a pair of 12v hair staraighteners. It did mean a drive into southampton to "Towsure", but it was worth it. They also had a range of the 240v hook up leads with the 3 pin sockets and circuit breakers on the end, but they`re £50 which at the moment is a bit more than we can afford, but we`ll get one for next year, OR, if, in the unlikely event, we decide we can risk the expense of our own boat . But for this year, a very kind Norwich forumite has kindly offered the loan of his . Regards to all ......... Neil.

[Stranger]

lol Neil i would have got a gas powered one no lekky needed then

[g0akc]

Apologies for replying to an old post.

I've tried GHD hair straighteners on a couple of 500W inverters powered from my Land Rover's battery. GHD MkIV and MkV (4 & 5) models worked OK, but you need a GOOD connection to the battery, with the engine running. As mentioned, the voltage drop on the DC wiring can be considerable as the current will be around 25 or 30A during the warm up period.

A cigar lighter socket is unlikely to be suitable.

I've got a hire cruiser booked for an upcoming trip and I'm wondering if I will be able to gain convenient access to the boat's battery to connect my inverter with short leads/croc clips.

Older GHD Mk3.1 straighteners would not work - presumably they did not like the waveform.

[Hockham Admiral]

I've got a hire cruiser booked for an upcoming trip and I'm wondering if I will be able to gain convenient access to the boat's battery to connect my inverter with short leads/croc clips.

.

I'm sure you could but I doubt the hire yard would be too impressed if you knackered their electrics!!!

[NorfolkNog]

I think I’d be a bit cautious. Even with expert knowledge the boatyard would probably not sanction this. All boats have at least 2 batteries – a cranking (starter) battery and a leisure battery to run the domestics. The idea being that even if you flatten the domestic battery you can still start the engine. If the inverter was connected across the cranking battery it could flatten it in which case the boatyard would have to be called out which they probably wouldn’t appreciate. Some boats even have a dedicated battery for the inverter. Swancraft for example have all their boats (bar one – generator) fitted with 1400 watt inverters which should be more than ample to run hair straighteners.

[Hockham Admiral]

Howard, Hi.

Personally I prefer my curly hair to stay that way............

[NorfolkNog]

Personally I prefer my curly hair to stay that way........

[Guest DAYTONA-BILL]

Apologies for replying to an old post.

I've tried GHD hair straighteners on a couple of 500W inverters powered from my Land Rover's battery. GHD MkIV and MkV (4 & 5) models worked OK, but you need a GOOD connection to the battery, with the engine running. As mentioned, the voltage drop on the DC wiring can be considerable as the current will be around 25 or 30A during the warm up period.

A cigar lighter socket is unlikely to be suitable.

I've got a hire cruiser booked for an upcoming trip and I'm wondering if I will be able to gain convenient access to the boat's battery to connect my inverter with short leads/croc clips.

Older GHD Mk3.1 straighteners would not work - presumably they did not like the waveform.

DON`T EVEN THINK ABOUT IT .

If you start messing with the boats systems, there`s no telling what damage you may do, even accidentally. If you were to interfere with the boats electrics, and "god forbid" there`s some sort of short, or an elctrical fire, you could end up with a hire fleet operator suing you, not just for the cost of the boat, but also the loss of revinue that boat will bring, not to mention the possibility of risking a fire to any boats moored next to you. It`s just not worth the risk, so personally, i`d just go out and buy a pair of the 12v ones that are available. As i`ve posted on another thread, we bought some last year for my wife, and they worked very well. In comparison, considering the difference of a 240v hair dryer, to a 12v one, the difference in performance is huge, whereas the difference in performance of the 240v and 12v hair straighteners is much much closer.

[Antares_9]

12vDC straighteners should be fine, unlike dryers which have the heat ripped away from them by a fan (not unlike 12vDC demisters) which means the voltage and more importantly amps available can simply not produce the heat quickly enough, it would be possible to produce ones that do but the cable size required and the size of the unit would make it impractical and unweildy. Straighteners on the other hand (good quality ones anyway) actually store the heat for use in ceramic or other suitable material pads, you may have to wait for them to heat up after using them for a minute or two but the performance should be acceptable. You can't fight Ohm's law, just work with it. And as Neil and others have said, don't fiddle with any part of a hire boat, or anything else for that matter without the owners permission, I know its ultra low voltage but given a path to the return it can still make a mess of your and other peoples day.

[MBA Marine]

12vDC straighteners should be fine, unlike dryers which have the heat ripped away from them by a fan (not unlike 12vDC demisters) which means the voltage and more importantly amps available can simply not produce the heat quickly enough, it would be possible to produce ones that do but the cable size required and the size of the unit would make it impractical and unweildy. Straighteners on the other hand (good quality ones anyway) actually store the heat for use in ceramic or other suitable material pads, you may have to wait for them to heat up after using them for a minute or two but the performance should be acceptable. You can't fight Ohm's law, just work with it. And as Neil and others have said, don't fiddle with any part of a hire boat, or anything else for that matter without the owners permission, I know its ultra low voltage but given a path to the return it can still make a mess of your and other peoples day.

does it annoy you as it does me that people think 12v is safe because its a low voltage? its the amount of current that can discharge thats the problem, please dont try it at home but do people know a mess it can make of a spanner if it arcs accross the poles? and the mess of your hand if the spanner is not insulated.

not many people die from a tazer and how many thousand volts are they but amperage is low or you would fry!

I was talking to a guy the other day who was bragging he had 10x 110Ah on his 12v system (live aboard) and all i was thinking was i hope he never get on the wrong side of it.

[Antares_9]

does it annoy you as it does me that people think 12v is safe because its a low voltage? its the amount of current that can discharge thats the problem, please dont try it at home but do people know a mess it can make of a spanner if it arcs accross the poles? and the mess of your hand if the spanner is not insulated.

not many people die from a tazer and how many thousand volts are they but amperage is low or you would fry!

I was talking to a guy the other day who was bragging he had 10x 110Ah on his 12v system (live aboard) and all i was thinking was i hope he never get on the wrong side of it.

Not so much annoys as reminds me not to park my ship near theirs. I can't see an issue with an install of that size though, if done correctly with MRBFs to protect it, I wouldn't hessitate to sign it off, I agree though if incorrectly executed it has potential to supply a high current for a longer time not only as designed but also as not designed and I see your point on that score.