Off Grid Home Forums Technical Discussion 12v vacuum cleaner Re: 12v vacuum cleaner


After blowing the fuse in a friends car by plugging in my laptop I discovered that the normal automotive standard for cigarette lighter outlets was 8 Amps max I took a look at the whole issue. As a marine electrician I must have installed dozen and dozens of such lighter outlets in boats but always wired them with fuses and wire gauge to handle 15 amps. The damn things are an anachronism dating back to WW2 when it was considered cool to light up while cruising down the road in your Studz Bearcat convertible looking like some Hollywood jerk in the movies.

BTW crocodile clips are not really suited for lots of amps, they are just convenient. There is insufficient contact area for a solid connection to carry all that current. When I worked for Xantrex we included a note in our product manual to cut off the cig plug and hard wire even our 300 watt product. the reason being at 300 watts @12V the DC current is 30 amps. The only reason we made small inverters with a cigarette plug was because a major retailer demanded these be included as a condition of them buying the small inverters by the truck load.

If you need plug-in convenience look for something called Anderson connectors. They make plugs rated as much as 200 amps DC and I have used them on 2000 watt inverters.

For an over view of what is available in small dimension connectors look at companies like MOLEX industrial catalog then find an electronics resale outlet who can order in small quantities. In North America Digikey is an excellent source but I am not familiar with UK retailers.

Sometimes you can improvise by cannibalizing old computers most of the connectors and pins used are good for 10A at 12V

Now that even older models of computers found in the rubbish bin have USB ports you can often find wire assemblies with A suitable USB socket suitable for other projects. Look for desk top computes having USB sockets in front panels. these invariably plug into the mother board with a wire harness. If you intend to carry a full 10A best upgrade the wire size. A normal USB current rating is under 1 amps. Wires used in computers may be as small as #22 or the metric equivalent. The wires coming out of most power supplies are #18 and can carry 10A.