Charles Chodkowski Posted January 17, 2014 Share Posted January 17, 2014 On a cigarette plug is the centre positive(live) and the outside negative(earth). I have a 150w pure sine inverter which I want to wire directly to the leisure battery (using a 15amp fuse of course) Link to comment Share on other sites More sharing options...
capcloser Posted January 17, 2014 Share Posted January 17, 2014 I'm pretty sure it is centre pos outside neg but dont wire it on my say so please :-( Link to comment Share on other sites More sharing options...
paulmold Posted January 17, 2014 Share Posted January 17, 2014 Correct Link to comment Share on other sites More sharing options...
capcloser Posted January 17, 2014 Share Posted January 17, 2014 Also partner just said our 300watt inverter has removable wires on the back so we can choose to use either cigarette plug or wired to battery,it came with both wires Link to comment Share on other sites More sharing options...
Keithl Posted January 17, 2014 Share Posted January 17, 2014 Charles, Keep 12v wires as short as possible and use longer mains wire if necessary to avoid excessive voltage drop on the 12v where the current will be higher (power loss is square of current times resistance so will be higher for lower voltage). Also a 15 Amp fuse may not be sufficient as the inverter is likely to draw significantly more on start up, be warned. And Yes, centre pin is positive. Keith. Link to comment Share on other sites More sharing options...
tonyg3nwl Posted January 17, 2014 Share Posted January 17, 2014 Hi, Are you are sure that your vehicle battery is negative connected to chassis. It probably is but do check it first at the vehicle battery. Then buy a spare unwired cigarette lighter plug and open it up as though you were going to add some wiring to it. Get your test meter and check which is which on the connections. You have a test meter of course, The socket may Not be live until you switch on engine and start it. Assuming it is live, then you will need to check the existing fuse rating that feeds the socket, AND THE RATING OF THE WIRE TO THE SOCKET. DO NOT ASSUME THAT IS RATED AT 15 AMPS, IT PROBABLY IS NOT, AND MAY BE ONLY 8 OR 10 AMP RATING. It is very unlikely that your invertor can be run from this socket, as the socket contacts themselves are neverman enough to handle the kind of current your inverter would require at working load. Please get the proper wiring done by an acknowledged auto electrician. You could be risking a fire by overloading underrated wiring. Take Care. tonyg3nwl I strongly advise NOT attempting to use the socket in this way, but get proper wiring done direct from the battery. I would hate to hear of a resultant fire damaged motorhome. Link to comment Share on other sites More sharing options...
Keithl Posted January 17, 2014 Share Posted January 17, 2014 Tony, Charles did say that he wanted to wire a new socket directly from the leisure battery using a 15A fuse and not use an existing one... Charles Chodkowski - 2014-01-17 3:19 PM On a cigarette plug is the centre positive(live) and the outside negative(earth). I have a 150w pure sine inverter which I want to wire directly to the leisure battery (using a 15amp fuse of course) But I do agree with you, check and double check polarity and connections before powering up any new wiring and sockets. Keith. Link to comment Share on other sites More sharing options...
T8LEY Posted January 17, 2014 Share Posted January 17, 2014 I'm confused with some of the replies you've had. I don't see where you mentioned a cigarette socket and can't work out how it's been assumed you are going to use one when you clearly said you wanted to connect an inverter directly to your leisure battery. Your query has been answered indirectly by references to sockets by others. You need a 20A fuse for a 150W pure sine wave inverter. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted January 18, 2014 Share Posted January 18, 2014 T8LEY - 2014-01-17 11:04 PM I'm confused with some of the replies you've had. I don't see where you mentioned a cigarette socket and can't work out how it's been assumed you are going to use one when you clearly said you wanted to connect an inverter directly to your leisure battery. Your query has been answered indirectly by references to sockets by others. You need a 20A fuse for a 150W pure sine wave inverter. It's likely that Charles' 150W inverter is fitted with a 'cigarette-lighter'-type plug (as many lowish-output inverters are). As Keith says, Charles seems to be planning to rig up wiring from his leisure-battery using a 15A-fused power-supply and a 'cigarette-lighter'-type socket to which he can connect his inverter's plug. Presumably Charles has inquired about the normal 'polarity' of a cigarette-lighter-type plug so that he can ensure that the socket he'll be fitting to the cabling from his leisure-battery matches. A 12V 150W inverter may have a peak output well above its continuous rating, as in the following example. In such cases the fuse used will need to reflect the peak output. http://www.maplin.co.uk/p/maplin-12v-pure-sinewave-150w-inverter-a71jw 'capcloser' mentions "...our 300watt inverter..." If 300W is the inverter's continuous output, a fuse of 30A would be needed and even that may not be adequate to deal with 'peaking'. It's unlikely that any vehicle's dashboard socket would be suitable for plugging in a 300W inverter and it's doubtful that auxiliary sockets (as advertised on the following webpage) would have an adequate Amperage rating. https://www.roadpro.co.uk/retail/product_level_2.aspx?prod=Plugs,+Sockets+and+Adaptors+12V+and+24V Link to comment Share on other sites More sharing options...
colin Posted January 18, 2014 Share Posted January 18, 2014 T8LEY - 2014-01-17 11:04 PM I'm confused with some of the replies you've had. I don't see where you mentioned a cigarette socket and can't work out how it's been assumed you are going to use one when you clearly said you wanted to connect an inverter directly to your leisure battery. Your query has been answered indirectly by references to sockets by others. You need a 20A fuse for a 150W pure sine wave inverter. Yes I thought same, wiring a inverter direct to battery is not the same as "I want to wire a cigarette socket to battery" Link to comment Share on other sites More sharing options...
T8LEY Posted January 18, 2014 Share Posted January 18, 2014 Derek Uzzell - 2014-01-18 9:27 AM T8LEY - 2014-01-17 11:04 PM I'm confused with some of the replies you've had. I don't see where you mentioned a cigarette socket and can't work out how it's been assumed you are going to use one when you clearly said you wanted to connect an inverter directly to your leisure battery. Your query has been answered indirectly by references to sockets by others. You need a 20A fuse for a 150W pure sine wave inverter. It's likely that Charles' 150W inverter is fitted with a 'cigarette-lighter'-type plug (as many lowish-output inverters are). -- I'll go along with the possibility but In that case he is limiting his supply to 15A, the maximum rating of a cigarette lighter plug (They can also come with other types of wired connection). As Keith says, Charles seems to be planning to rig up wiring from his leisure-battery using a 15A-fused power-supply and a 'cigarette-lighter'-type socket to which he can connect his inverter's plug. Presumably Charles has inquired about the normal 'polarity' of a cigarette-lighter-type plug so that he can ensure that the socket he'll be fitting to the cabling from his leisure-battery matches. -- Don't see where he mentioned a cigarette lighter socket. He clearly stated he wanted to connect his inverter directly to a battery. A 12V 150W inverter may have a peak output well above its continuous rating, as in the following example. In such cases the fuse used will need to reflect the peak output. http://www.maplin.co.uk/p/maplin-12v-pure-sinewave-150w-inverter-a71jw -- So how will a 15A cigarette lighter fuse cope with what you suggest above if that is the case? 'capcloser' mentions "...our 300watt inverter..." If 300W is the inverter's continuous output, a fuse of 30A would be needed and even that may not be adequate to deal with 'peaking'. It's unlikely that any vehicle's dashboard socket would be suitable for plugging in a 300W inverter and it's doubtful that auxiliary sockets (as advertised on the following webpage) would have an adequate Amperage rating. -- What relevance has this information? Or, are you confirming what you originally suggested won't work?? https://www.roadpro.co.uk/retail/product_level_2.aspx?prod=Plugs,+Sockets+and+Adaptors+12V+and+24V (>) (>) The OP asked about polarity and advised he was connecting some equipment in a particular way. Anything else is speculation; So why perpetuate it? Link to comment Share on other sites More sharing options...
Charles Chodkowski Posted January 18, 2014 Author Share Posted January 18, 2014 I will be wiring directly to the battery - not a socket. I never mentioned socket in my initial thread!!!! 15amp is the fuse size Maplin recommend. Link to comment Share on other sites More sharing options...
Keithl Posted January 18, 2014 Share Posted January 18, 2014 OK I understand now. It was just that you asked about cigar lighter plugs and then wiring up the inverter all in the same paragraph. I suppose I (and others) assumed the inverter had a cigar lighter plug fitted and you where asking about polarity as to how to wire up a socket for it. Sorry if we misled others, Keith. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.