How big a DC to AC inverter can I plug into cig lighter socket?

Discussion in 'ICE (In Car Entertainment)' started by Not THAT kind of 'escort', Jan 17, 2017.

  1. Not THAT kind of 'escort'

    Not THAT kind of 'escort' FEOA Donator

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    http://www.ebay.com/sch/i.html?_fro...&_nkw=automovtive DC to AC converter&_sacat=0

    ultimately, of course, I want to run heavy power tools out of the back of my wagon, which would require big fat wires from battery to a big fat inverter, etc.

    But how much wattage can I realistically get out the cig lighter of a 1992 Escort?

    Can I run plug a 3 way expander and run a 40w laptop with 12v to 17.3v AND a 27" monitor?
  2. neuspeedescort

    neuspeedescort FEOA Member

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    do it right from the start. get an extra battery and trunk mount it. your wiring to the cigar lighter is only going to be good to about 5 amps. it would likely barely run the laptop if you're that lucky.
  3. cwol97401

    cwol97401 FEOA Member

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    The lighter socket fuse on a Ford Escort is rated at 20 amps if its installed properly. 20 amps at 12 volts equals 240 Watts. When using an inverter always look at the watt output of the inverter, not the volts or the amps. Watts do not change when you're going through an inverter only the amps and volts. So if your inverter is rated at more than 240 Watts roughly you should consider hooking it directly to the battery. Also I agree that a second battery installed in the rear is a better option than plugging into the cigarette lighter socket. You can always run an isolator from the alternator to charge the battery in the rear when the engine battery does not need charged, just like they do in RVs and large trucks.

    Tapatalk
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  4. neuspeedescort

    neuspeedescort FEOA Member

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    that 20 amp fuse is the popping point. the wiring to the cigar lighter is low strand count 18 or 20ga. that is really only good to about 70 watts constant. it will hit thermal point and start getting warm = melting from the inside out. second battery should be the only way you are thinking. run at minimum a 4ga wire to the second battery. fuse it just after your front battery and just before the rear. if you're planning on doing more equipment in the future a large output alternator and 0ga wire should be considered.
  5. cwol97401

    cwol97401 FEOA Member

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    The theory behind fuses is simply protect wiring. A fuse is designed to fail long before the wires it was installed to protect. Otherwise, why even have a fuse to begin with? I'm certain Ford would not install a wire that could burn up at seven amps and then protect it with a 20 amp fuse. That's a class-action suit just waiting to happen.

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  6. denisond3

    denisond3 Moderator Staff Member

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    Agree with above advice.
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  7. neuspeedescort

    neuspeedescort FEOA Member

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    agreed. lawsuit would ensue. but look at ohms law and a wire gauge chart. it's that simple. if you pulled 20 amps thru that wire it would get hot. no two ways about it.

    http://www.bigboyzheadporting.com/ohmslaw.htm

    http://connersrepair.com/wp-content/themes/redux1-2/pdf/Conner's Wire Chart.pdf
  8. zzyzzx

    zzyzzx FEOA Member

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    Honestly, you can barely run a drill or any other power tool off of any inverter that you can plug into the lighter socket. If you wanted to run a shop vac, or anything more substantial than a drill than you want to connect the inverter directly to the car battery.
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  9. novanutcase

    novanutcase FEOA Member

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    CWOL - While I agree, in theory, with what you are saying I think Neuspeed's suggestion would be a better way to go for the OP. Especially since he will be running heavy power tools off of it that will be pulling some serious amps. It would suck to be in the middle of a job only to have the fuse blow and have to get in there and replace the fuse.

    If it were me I would find a battery box that will fit a 2 gang box along with the battery comfortably. This way he has 4 plugs, if that's what he needs, or he can install a single gang box/2 plugs, again, depending on his needs. I would also mount the inverter to the side of the box so that you have the shortest distance from the battery to the inverter.

    I'd also run 02 wire directly from the engine bay battery to the rear battery.

    Of course the easiest solution would be to just go buy a gas powered generator from Harbor Freight. For $300, more or less, you can get a 3200 watt running/4000 watt peak generator with (2) 120V , 20A duplex outlets, 3 prong, (1) 240V, 30A twist lock outlet, 4 prong, (1) 12V DC outlet and a GFCI outlet to boot.

    http://www.harborfreight.com/4000-peak3200-running-watts-65-hp-212cc-generator-epa-iii-63080.html

    The cost of a battery, battery box, inverter, 02 cabling and all the other miscellaneous stuff you'll need along with the labor involved would add up to pretty much what you spend on the generator.

    Just my .02!

    John
    Last edited: Feb 3, 2017
  10. cwol97401

    cwol97401 FEOA Member

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    John, I agree with the second battery idea as well. I'm only tried to state what the factory wiring is capable of. I've blown enough hard to find fuses to know not to draw heavy loads through them stock, but knowing their limits is useful when needed, as opposed to severely underestimating them if needed. If I needed this amount of power out of my wagon, I would have a marine battery and a large inverter setup. Carrying a generator around in the back of an escort isn't always practical.

    Tapatalk
    Edit: I would use a battery isolator and keep the batteries seperate so I don't end up with a dead starting battery at the end of the day.
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  11. novanutcase

    novanutcase FEOA Member

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    True but you can always take it out when you aren't using it. It would be handy to have a portable generator rather than a fixed one bolted to the back of the wagon.

    Again, theoretically I agree with you but I, like Neuspeed, don't like to push anything to it's limits if you don't have to. Better to have some headroom especially with all things electrical.

    John
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